Merge remote-tracking branch 'origin/main' into HEAD

docs: remove the README build section
chore: v0.1.33
2026-11-07 18:38:33 -10:00 · 2026-11-01 18:59:17 +08:00 · 2026-11-01 18:46:40 +08:00 · 2026-11-01 18:35:25 +08:00 · 2026-11-01 18:26:24 +08:00 · 2026-11-01 18:05:05 +08:00
389 changed files with 21350 additions and 1380 deletions
@@ -4038,7 +4038,7 @@ checksum = "3d3067d79b975e8844ca9eb072e16b31c3c1c36928edf9c6789548c524d0d954"

 [[package]]
 name = "ide-agent"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dunce",
 "encoding_rs",
@@ -4061,7 +4061,7 @@ dependencies = [

 [[package]]
 name = "ide-analysis"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ast-grep-core",
 "ide-core",
@@ -4075,7 +4075,7 @@ dependencies = [

 [[package]]
 name = "ide-build"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dirs 6.0.0",
 "dunce",
@@ -4090,7 +4090,7 @@ dependencies = [

 [[package]]
 name = "ide-clipboard"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "objc2 0.6.5",
 "objc2-app-kit 0.3.2",
@@ -4099,7 +4099,7 @@ dependencies = [

 [[package]]
 name = "ide-core"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dunce",
 "encoding_rs",
@@ -4115,7 +4115,7 @@ dependencies = [

 [[package]]
 name = "ide-coverage"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "ide-run",
@@ -4129,7 +4129,7 @@ dependencies = [

 [[package]]
 name = "ide-dap"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "ide-jsonrpc",
@@ -4147,7 +4147,7 @@ dependencies = [

 [[package]]
 name = "ide-db"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "bb8",
 "dirs 6.0.0",
@@ -4169,7 +4169,7 @@ dependencies = [

 [[package]]
 name = "ide-docker"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "libc",
@@ -4183,18 +4183,19 @@ dependencies = [

 [[package]]
 name = "ide-fonts"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "objc2-core-foundation",
 "objc2-core-text",
 "serde",
+ "serde_json",
 "specta",
 "windows",
 ]

 [[package]]
 name = "ide-github"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "ide-vcs",
@@ -4208,7 +4209,7 @@ dependencies = [

 [[package]]
 name = "ide-host"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dirs 6.0.0",
 "dunce",
@@ -4253,7 +4254,7 @@ dependencies = [

 [[package]]
 name = "ide-http"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "parking_lot",
@@ -4271,7 +4272,7 @@ dependencies = [

 [[package]]
 name = "ide-index"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "blake3",
 "criterion",
@@ -4293,7 +4294,7 @@ dependencies = [

 [[package]]
 name = "ide-jsonrpc"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "encoding_rs",
 "futures",
@@ -4309,7 +4310,7 @@ dependencies = [

 [[package]]
 name = "ide-language"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "blake3",
 "criterion",
@@ -4364,7 +4365,7 @@ dependencies = [

 [[package]]
 name = "ide-lsp"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dunce",
 "futures",
@@ -4373,6 +4374,7 @@ dependencies = [
 "ide-jsonrpc",
 "ide-language",
 "ide-text",
+ "ide-vfs",
 "ignore",
 "lsp-types",
 "parking_lot",
@@ -4388,7 +4390,7 @@ dependencies = [

 [[package]]
 name = "ide-notebook"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "futures",
 "ide-core",
@@ -4411,7 +4413,7 @@ dependencies = [

 [[package]]
 name = "ide-plugin"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "ide-language",
@@ -4429,7 +4431,7 @@ dependencies = [

 [[package]]
 name = "ide-profiler"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "ide-run",
@@ -4442,7 +4444,7 @@ dependencies = [

 [[package]]
 name = "ide-remote"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "globset",
 "ide-core",
@@ -4459,7 +4461,7 @@ dependencies = [

 [[package]]
 name = "ide-run"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dunce",
 "encoding_rs",
@@ -4482,7 +4484,7 @@ dependencies = [

 [[package]]
 name = "ide-sdk"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dunce",
 "ide-core",
@@ -4501,7 +4503,7 @@ dependencies = [

 [[package]]
 name = "ide-search"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "criterion",
 "globset",
@@ -4521,7 +4523,7 @@ dependencies = [

 [[package]]
 name = "ide-spell"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "parking_lot",
@@ -4534,7 +4536,7 @@ dependencies = [

 [[package]]
 name = "ide-ssh"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dirs 6.0.0",
 "flate2",
@@ -4553,7 +4555,7 @@ dependencies = [

 [[package]]
 name = "ide-syntax"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "ide-language",
@@ -4568,7 +4570,7 @@ dependencies = [

 [[package]]
 name = "ide-terminal"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "libc",
@@ -4581,7 +4583,7 @@ dependencies = [

 [[package]]
 name = "ide-text"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "criterion",
 "ide-core",
@@ -4593,7 +4595,7 @@ dependencies = [

 [[package]]
 name = "ide-tools"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "flate2",
 "hex",
@@ -4614,7 +4616,7 @@ dependencies = [

 [[package]]
 name = "ide-vcs"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "dunce",
 "encoding_rs",
@@ -4633,7 +4635,7 @@ dependencies = [

 [[package]]
 name = "ide-vfs"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "chardetng",
 "dunce",
@@ -4655,7 +4657,7 @@ dependencies = [

 [[package]]
 name = "ide-web"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "ide-core",
 "open",
@@ -4671,7 +4673,7 @@ dependencies = [

 [[package]]
 name = "ide-workspace"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "blake3",
 "dunce",
@@ -5806,6 +5808,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2a180dd8642fa45cdb7dd721cd4c11b1cadd4929ce112ebd8b9f5803cc79d536"
 dependencies = [
 "bitflags 2.13.2",
+ "block2 0.6.2",
 "dispatch2",
 "objc2 0.6.5",
 ]
@@ -6141,7 +6144,7 @@ dependencies = [

 [[package]]
 name = "openidea"
-version = "0.1.32"
+version = "0.1.33"
 dependencies = [
 "blake3",
 "block2 0.6.2",
@@ -6183,7 +6186,9 @@ dependencies = [
 "ide-workspace",
 "objc2 0.6.5",
 "objc2-app-kit 0.3.2",
+ "objc2-core-foundation",
 "objc2-foundation 0.3.2",
+ "objc2-web-kit 0.3.2",
 "parking_lot",
 "serde",
 "serde_json",
@@ -3,7 +3,7 @@ resolver = "3"
 members = ["crates/*", "src-tauri"]

 [workspace.package]
-version = "0.1.32"
+version = "0.1.33"
 edition = "2024"
 rust-version = "1.96"
 license = "Apache-2.0"
@@ -14,8 +14,6 @@
  &nbsp;·&nbsp;
  <a href="#benchmark">Benchmark</a>
  &nbsp;·&nbsp;
-  <a href="#build">Build</a>
-  &nbsp;·&nbsp;
  <a href="https://discord.gg/2Zy4yn7gP">Discord</a>
 </p>

@@ -47,24 +45,6 @@ IDEA analyses Python more deeply, so "ready" doesn't mean the same work on
 both sides. Both are measured from the outside, the same way: see
 [`perf/compare`](perf/compare) to run it on your machine and projects.

-## Build
-
-```sh
-pnpm install
-pnpm tauri dev
-```
-
-Rust 1.96, Node 22, pnpm and the [Tauri prerequisites](https://v2.tauri.app/start/prerequisites/).
-
-Native notebook execution tests are opt-in and need two distinct Python environments
-with `ipykernel` installed:
-
-```sh
-OPENIDEA_TEST_PYTHON=/first/env/bin/python \
-OPENIDEA_TEST_PYTHON_SECOND=/second/env/bin/python \
-cargo test -p ide-notebook --test kernel_runtime -- --ignored --test-threads=1
-```
-
 ## License

 [Apache 2.0](LICENSE). Bundled third-party assets are listed in [`THIRD_PARTY_LICENSES.md`](THIRD_PARTY_LICENSES.md).
@@ -1,5 +1,13 @@
 # Third-party licenses

+## Project Lombok
+
+`plugins/lombok/lombok-1.18.48-openidea.1.jar` contains Project Lombok v1.18.48 with the Equinox
+classloader fix from [projectlombok/lombok#4059](https://github.com/projectlombok/lombok/pull/4059).
+Copyright (C) 2009-2021 The Project Lombok Authors. MIT license and bundled component
+notices are retained in [plugins/lombok/LICENSE](plugins/lombok/LICENSE) and inside the jar.
+Source tag, patch commits and build instructions: [plugins/lombok/README.md](plugins/lombok/README.md).
+
 ## JetBrains IntelliJ Platform icons

 `src/ui/expui/**` contains SVG icons from the IntelliJ Platform "new UI" (expui)
@@ -27,6 +35,20 @@ icon set, copied unmodified (some renamed) from JetBrains' open-source repositor
  `fileTypes/hashiCorp`, Apache-2.0); `makefile` (`expui/makefile` →
  `fileTypes/makefile`, MIT, Copyright (c) 2016 Victor Kropp — full text below).

+The read/write usage filter assets (`actions/showReadAccess{,_dark}.svg` and
+`actions/showWriteAccess{,_dark}.svg`) are copied unmodified from
+`platform/icons/src/expui/actions/` at intellij-community commit
+[`e992ff4750b4c36afe2caadfa8b191a8f36fb7a2`](https://github.com/JetBrains/intellij-community/tree/e992ff4750b4c36afe2caadfa8b191a8f36fb7a2/platform/icons/src/expui/actions).
+Their original copyright headers and Apache-2.0 licensing are retained.
+
+- [intellij-rust](https://github.com/intellij-rust/intellij-rust) (MIT):
+  `src/main/resources/icons/expui/rustFile{,_dark}.svg` →
+  `src/ui/expui/fileTypes/rust{,_dark}.svg`;
+  `src/main/resources/icons/expui/cargo{,_dark}.svg` and `cargoLock{,_dark}.svg` →
+  `src/ui/expui/fileTypes/cargo{,_dark}.svg` and `cargoLock{,_dark}.svg`.
+  Copyright (c) 2015 Aleksey Kladov, Evgeny Kurbatsky, Alexey Kudinkin and contributors;
+  Copyright (c) 2016 JetBrains. MIT licence, full text below.
+
 At render time `src/ui/icons.tsx` may recolour monochrome icons to `currentColor`.

 ## JetBrains IntelliJ Platform diff algorithm
@@ -43,7 +65,7 @@ from its tests (`LineComparisonUtilTest`, `WordComparisonUtilTest`,
 JetBrains s.r.o. and contributors. Apache License 2.0 (below).

 `src/ui/openidea/**` holds OpenIDEA's own file-type icons drawn in the expui style for
-languages whose JetBrains icons are not open source (Go, Rust, Ruby, Dart, Lua, Zig,
+languages whose JetBrains icons are not open source (Go, Ruby, Dart, Lua, Zig,
 Svelte, …). Those using the page-with-corner-badge layout (`goMod`, `goWork`,
 `dotenv`, `readme`, `lock`, `license`) reuse the page outline of the Apache-2.0
 expui `fileTypes/h.svg`; that outline is modified from the original by JetBrains.
@@ -54,6 +76,31 @@ The lettering in `src-tauri/icons/source/openidea-wordmark*.svg` is outlined fro
 Inter Tight (Copyright 2022 The Inter Project Authors, SIL Open Font License 1.1,
 https://github.com/rsms/inter-tight).

+### MIT License (Rust and Cargo icons)
+
+The MIT License (MIT)
+
+Copyright (c) 2015 Aleksey Kladov, Evgeny Kurbatsky, Alexey Kudinkin and contributors
+Copyright (c) 2016 JetBrains
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
 ### MIT License (makefile icon)

 Copyright (c) 2016 Victor Kropp
@@ -915,7 +915,11 @@ impl Session {
                        } else {
                            "end_turn"
                        };
-                        finished = st.turn.take().map(|t| (t, TurnEnd::Stop(stop)));
+                        finished = st.turn.take().map(|mut t| {
+                            // Claude Code reports a turn that failed as cancelled here.
+                            let failure = t.failure.take().filter(|_| !t.cancelled);
+                            (t, failure.unwrap_or(TurnEnd::Stop(stop)))
+                        });
                    }
                }
                "assistant" if msg.get("parent_tool_use_id").is_none_or(Value::is_null) => {
@@ -1139,7 +1143,8 @@ where
 /// Whether `result` ends `turn`: it answers the turn's last message, or (stopped) any of
 /// its messages, or names none (the CLI's own error before the turn began).
 fn belongs(turn: &Turn, result: &Value) -> bool {
-    if result.get("origin").is_some_and(|o| !o.is_null()) {
+    // Prompts are sent with the origin `human`, and their results echo it.
+    if result.get("origin").is_some_and(|o| !o.is_null() && o.get("kind").and_then(Value::as_str) != Some("human")) {
        return false;
    }
    let mut uuids = strings(result.get("user_message_uuids"));
@@ -738,6 +738,50 @@ async fn a_stop_ahead_of_its_prompt_cancels_it() {
    assert!(cli.sent.lock()[0].iter().all(|m| m["type"] != "user"), "nothing was sent");
 }

+#[tokio::test(flavor = "multi_thread")]
+async fn a_failed_turn_reports_its_failure() {
+    let text = "Failed to authenticate: OAuth session expired and could not be refreshed";
+    let lifecycle = |uuid: &str, state: &str| {
+        Frame::Cli(json!({ "type": "command_lifecycle", "command_uuid": uuid, "state": state }))
+    };
+    let result = |uuid: &str| {
+        Frame::Cli(json!({
+            "type": "result", "subtype": "success", "is_error": true, "result": text, "stop_reason": "stop_sequence",
+            "terminal_reason": "api_error", "origin": { "kind": "human" }, "user_message_uuids": [uuid],
+        }))
+    };
+    // As Claude Code sends it, and with the turn's end ahead of its result.
+    for lifecycle_first in [false, true] {
+        let mut process = load_fixture("simple").remove(0);
+        process.truncate(6);
+        let Some(Frame::Shim(prompt)) = process.last() else { panic!("the fixture's prompt") };
+        let uuid = prompt["uuid"].as_str().unwrap().to_owned();
+        process.push(Frame::Cli(json!({
+            "type": "assistant", "error": "authentication_failed", "parent_tool_use_id": null,
+            "message": { "id": "m", "model": "<synthetic>", "content": [{ "type": "text", "text": text }] },
+        })));
+        if lifecycle_first {
+            process.extend([lifecycle(&uuid, "cancelled"), result(&uuid)]);
+        } else {
+            process.extend([result(&uuid), lifecycle(&uuid, "cancelled")]);
+        }
+        let cli = Arc::new(Replay {
+            processes: Mutex::new(VecDeque::from([process])),
+            sent: Arc::default(),
+            launched: Mutex::default(),
+            errors: Arc::default(),
+        });
+        let (dir, cwd) = (tempfile::tempdir().unwrap(), tempfile::tempdir().unwrap());
+        let h =
+            Harness::connect(cli.clone(), dir.path().into(), dir.path().join("p"), cwd.path().into(), Vec::new()).await;
+        let s = h.new_session().await;
+        let Err(RpcError::Server { message, .. }) = h.prompt(&s, "hi").await else {
+            panic!("the turn should fail (lifecycle first: {lifecycle_first})");
+        };
+        assert_eq!(message, format!("Claude Code authentication failed: {text}"));
+    }
+}
+
 /// Fork and undo against the real CLI, across connections, in a symlinked directory
 /// (macOS `/tmp`).
 #[tokio::test(flavor = "multi_thread")]
@@ -829,6 +873,7 @@ fn which_result_ends_a_turn() {
    assert!(!belongs(&t, &json!({"user_message_uuids": ["a"]})), "a steer superseded it");
    assert!(belongs(&t, &json!({"subtype": "error_during_execution"})), "names no message");
    assert!(!belongs(&t, &json!({"origin": {"kind": "task-notification"}})), "Claude Code's own turn");
+    assert!(belongs(&t, &json!({"origin": {"kind": "human"}, "user_message_uuids": ["b"]})), "the prompt's own result");
    assert!(belongs(&turn(&["a", "b"], true), &json!({"user_message_uuids": ["a"]})));
 }

@@ -0,0 +1,218 @@
+//! Resource processing by the project's build tool, then publishing to the live JVM's output directory.
+use crate::BuildModel;
+use ide_core::{IdeError, IdeResult};
+use std::collections::BTreeMap;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+pub struct ResourceBuild {
+    pub command: String,
+    pub args: Vec<String>,
+    pub cwd: String,
+    pub env: BTreeMap<String, String>,
+    pub kind: &'static str,
+}
+
+fn literal(value: &str) -> String {
+    format!("'{}'", value.replace('\\', "\\\\").replace('\'', "\\'"))
+}
+
+pub fn plan(root: &Path, model: &BuildModel, module: &Path, cache: &Path) -> IdeResult<ResourceBuild> {
+    fs::create_dir_all(cache)?;
+    let manifest = cache.join("resource-output.txt");
+    if manifest.exists() {
+        fs::remove_file(&manifest)?;
+    }
+    let module = dunce::canonicalize(root.join(module))?;
+    if let Some(p) = model.maven.as_ref().and_then(|m| m.projects.iter().find(|p| root.join(&p.dir) == module)) {
+        let mut args = p.options.clone();
+        args.extend([
+            "process-resources".into(),
+            "help:evaluate".into(),
+            "-Dexpression=project.build.outputDirectory".into(),
+            format!("-Doutput={}", manifest.display()),
+        ]);
+        return Ok(ResourceBuild {
+            command: p.command.clone(),
+            args,
+            cwd: p.dir.clone(),
+            env: p.env.clone(),
+            kind: "maven",
+        });
+    }
+    if let Some(g) = &model.gradle
+        && let Some(p) = g.projects.iter().find(|p| root.join(&p.dir) == module)
+    {
+        let script = cache.join("resources.init.gradle");
+        fs::write(
+            &script,
+            format!(
+                r#"gradle.projectsEvaluated {{
+    def p = gradle.rootProject.project({})
+    def resources = p.tasks.named('processResources')
+    p.tasks.register('openideaUpdateResources') {{
+        dependsOn resources
+        doLast {{ new File({}).setText(resources.get().destinationDir.absolutePath, 'UTF-8') }}
+    }}
+}}
+"#,
+                literal(&p.path),
+                literal(&manifest.to_string_lossy())
+            ),
+        )?;
+        return Ok(ResourceBuild {
+            command: g.command.clone(),
+            args: vec![
+                "--init-script".into(),
+                script.to_string_lossy().into_owned(),
+                format!("{}:openideaUpdateResources", p.path.trim_end_matches(':')),
+            ],
+            cwd: g.dir.clone(),
+            env: g.env.clone(),
+            kind: "gradle",
+        });
+    }
+    Err(IdeError::invalid("The Spring Boot module must belong to a linked Maven or Gradle build"))
+}
+
+pub fn publish(root: &Path, cache: &Path, class_paths: &[String], main_class: &str) -> IdeResult<()> {
+    let output = PathBuf::from(fs::read_to_string(cache.join("resource-output.txt"))?.trim());
+    if !output.is_absolute() || !output.is_dir() {
+        return Err(IdeError::invalid("The resource build did not report an output directory"));
+    }
+    let output = dunce::canonicalize(output)?;
+    let paths: Vec<_> = class_paths.iter().filter_map(|p| dunce::canonicalize(root.join(p)).ok()).collect();
+    // A separate resource directory is already on the runtime classpath (e.g. build/resources/main).
+    if paths.contains(&output) {
+        return Ok(());
+    }
+    // jdtls uses bin/main for Gradle, rather than Gradle's build/resources/main.
+    let class_file = main_class.split('.').collect::<PathBuf>().with_extension("class");
+    let destination = paths.iter().find(|p| p.join(&class_file).is_file()).ok_or_else(|| {
+        IdeError::invalid("Cannot find the running main class output directory; restart the application")
+    })?;
+    let previous: Vec<String> = fs::read(cache.join("published-resources.json"))
+        .ok()
+        .and_then(|bytes| serde_json::from_slice(&bytes).ok())
+        .unwrap_or_default();
+    let mut current = Vec::new();
+    copy_resources(&output, &output, destination, &mut current)?;
+    for rel in previous.iter().filter(|p| !current.contains(p)) {
+        let path = destination.join(rel);
+        if path.is_file() {
+            fs::remove_file(path)?;
+        }
+    }
+    fs::write(
+        cache.join("published-resources.json"),
+        serde_json::to_vec(&current).map_err(|e| IdeError::internal(e.to_string()))?,
+    )?;
+    Ok(())
+}
+
+fn copy_resources(root: &Path, from: &Path, to: &Path, copied: &mut Vec<String>) -> IdeResult<()> {
+    for entry in fs::read_dir(from)? {
+        let entry = entry?;
+        let path = entry.path();
+        let kind = entry.file_type()?;
+        if kind.is_symlink() {
+            continue;
+        }
+        if kind.is_dir() {
+            copy_resources(root, &path, to, copied)?;
+        } else if kind.is_file() && path.extension().is_none_or(|e| e != "class") {
+            let rel = path.strip_prefix(root).map_err(|e| IdeError::internal(e.to_string()))?;
+            let dest = to.join(rel);
+            if let Some(parent) = dest.parent() {
+                fs::create_dir_all(parent)?;
+            }
+            fs::copy(&path, dest)?;
+            copied.push(rel.to_string_lossy().into_owned());
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn resource_plans_use_the_selected_module_and_build_configuration() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        fs::create_dir(root.join("app")).unwrap();
+        let mut model = BuildModel {
+            maven: Some(crate::MavenModel {
+                projects: vec![crate::MavenProject {
+                    dir: "app".into(),
+                    command: "/tools/mvnw".into(),
+                    options: vec!["-Pdev".into()],
+                    env: BTreeMap::from([("JAVA_HOME".into(), "/jdk".into())]),
+                    ..Default::default()
+                }],
+                ..Default::default()
+            }),
+            ..Default::default()
+        };
+        let cache = root.join("cache");
+        let maven = plan(&root, &model, Path::new("app"), &cache).unwrap();
+        assert_eq!(maven.command, "/tools/mvnw");
+        assert_eq!(maven.cwd, "app");
+        assert_eq!(maven.args[0..2], ["-Pdev", "process-resources"]);
+        assert!(maven.args.contains(&"-Dexpression=project.build.outputDirectory".into()));
+        assert_eq!(maven.env["JAVA_HOME"], "/jdk");
+        model.maven = None;
+        model.gradle = Some(crate::GradleModel {
+            command: "/tools/gradlew".into(),
+            projects: vec![crate::GradleProject { path: ":app".into(), dir: "app".into(), ..Default::default() }],
+            ..Default::default()
+        });
+        let gradle = plan(&root, &model, Path::new("app"), &cache).unwrap();
+        assert_eq!(gradle.command, "/tools/gradlew");
+        assert_eq!(gradle.args.last().unwrap(), ":app:openideaUpdateResources");
+        let script = fs::read_to_string(cache.join("resources.init.gradle")).unwrap();
+        assert!(script.contains("processResources") && script.contains("destinationDir.absolutePath"));
+        assert!(!script.contains("build/resources/main")); // The task owns custom output locations.
+    }
+
+    #[test]
+    fn publishes_maven_and_gradle_resource_outputs_to_the_runtime_classpath() {
+        for layout in ["target/classes", "build/resources/main", "custom resource output"] {
+            let tmp = tempfile::tempdir().unwrap();
+            let root = tmp.path();
+            let cache = root.join("cache");
+            let output = root.join(layout);
+            let runtime = if layout == "target/classes" { output.clone() } else { root.join("bin/main") };
+            fs::create_dir_all(output.join("static")).unwrap();
+            fs::create_dir_all(runtime.join("example")).unwrap();
+            fs::create_dir_all(&cache).unwrap();
+            fs::write(cache.join("resource-output.txt"), output.to_string_lossy().as_bytes()).unwrap();
+            fs::write(output.join("static/index.html"), "after").unwrap();
+            fs::write(output.join("unrelated.class"), "do not publish").unwrap();
+            fs::write(runtime.join("example/Application.class"), "running").unwrap();
+            publish(root, &cache, &[runtime.to_string_lossy().into_owned()], "example.Application").unwrap();
+            assert_eq!(fs::read_to_string(runtime.join("static/index.html")).unwrap(), "after");
+            assert_eq!(fs::read_to_string(runtime.join("example/Application.class")).unwrap(), "running");
+            if output != runtime {
+                assert!(!runtime.join("unrelated.class").exists());
+                fs::remove_file(output.join("static/index.html")).unwrap();
+                publish(root, &cache, &[runtime.to_string_lossy().into_owned()], "example.Application").unwrap();
+                assert!(!runtime.join("static/index.html").exists());
+            }
+        }
+    }
+
+    #[test]
+    fn leaves_separate_runtime_resource_directories_in_place_and_rejects_jar_only_runs() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let output = root.join("build/resources/main");
+        let cache = root.join("cache");
+        fs::create_dir_all(&output).unwrap();
+        fs::create_dir(&cache).unwrap();
+        fs::write(cache.join("resource-output.txt"), output.to_string_lossy().as_bytes()).unwrap();
+        publish(root, &cache, &[output.to_string_lossy().into_owned()], "a.Main").unwrap();
+        assert!(publish(root, &cache, &["app.jar".into()], "a.Main").is_err());
+    }
+}
@@ -0,0 +1,321 @@
+//! Metadata fingerprints for successful Maven launch builds.
+use super::*;
+use std::fs;
+use std::hash::{Hash, Hasher};
+use std::time::SystemTime;
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct LaunchFingerprint {
+    version: u32,
+    parameters: String,
+    files: BTreeMap<PathBuf, Option<(u64, SystemTime)>>,
+}
+
+fn scan(
+    path: &Path,
+    files: &mut BTreeMap<PathBuf, Option<(u64, SystemTime)>>,
+    ancestors: &mut HashSet<PathBuf>,
+    cancel: &CancellationToken,
+) -> IdeResult<()> {
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    let meta = match fs::metadata(path) {
+        Ok(meta) => meta,
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+            files.insert(path.to_path_buf(), None);
+            return Ok(());
+        }
+        Err(e) => return Err(e.into()),
+    };
+    if meta.is_dir() {
+        let canonical = dunce::canonicalize(path)?;
+        if !ancestors.insert(canonical.clone()) {
+            return Err(IdeError::internal("cyclic launch input directory"));
+        }
+        // Directory mtimes change on irrelevant JDT writes. File paths detect additions/deletions.
+        files.insert(path.to_path_buf(), None);
+        for entry in fs::read_dir(path)? {
+            scan(&entry?.path(), files, ancestors, cancel)?;
+        }
+        ancestors.remove(&canonical);
+    } else if meta.is_file() {
+        files.insert(path.to_path_buf(), Some((meta.len(), meta.modified()?)));
+    } else {
+        return Err(IdeError::internal("unsupported launch input file"));
+    }
+    Ok(())
+}
+
+/// `None` means an input cannot be resolved safely: build normally without reuse.
+/// All filesystem work belongs on the caller's blocking thread.
+pub fn launch_fingerprint(
+    root: &Path,
+    model: &BuildModel,
+    module: &Path,
+    test: bool,
+    local_repo: Option<PathBuf>,
+    cancel: &CancellationToken,
+) -> IdeResult<Option<LaunchFingerprint>> {
+    let Some(m) = &model.maven else { return Ok(None) };
+    let projects = maven_launch_projects(root, m, module, test);
+    if projects.is_empty() {
+        return Ok(None);
+    }
+    let Some(mut inputs) = maven::launch_inputs(root, &projects, local_repo) else { return Ok(None) };
+    let plan = launch_plan(root, model, module, test)?;
+    let mut environment: BTreeMap<String, String> = std::env::vars()
+        .map(|(key, value)| (key.to_ascii_uppercase(), value))
+        .filter(|(key, _)| {
+            key.starts_with("MAVEN_")
+                || key.starts_with("JAVA_")
+                || key.starts_with("JDK_")
+                || matches!(
+                    key.as_str(),
+                    "PATH" | "HOME" | "LANG" | "LC_ALL" | "_JAVA_OPTIONS" | "M2_HOME" | "MAVEN_HOME"
+                )
+        })
+        .collect();
+    // Explicit step values override the inherited environment just as they do in Command.
+    for step in &plan.steps {
+        environment.extend(step.env.iter().map(|(key, value)| (key.to_ascii_uppercase(), value.clone())));
+        for dir in step.cwd.ancestors() {
+            inputs.extend([dir.join(".mvn"), dir.join("mvnw"), dir.join("mvnw.cmd")]);
+            if dir == root {
+                break;
+            }
+        }
+        let program = process::program_path(&step.program, &step.env);
+        inputs.push(program.clone());
+        // Maven installed via a symlink still reads conf from its distribution.
+        if let Ok(program) = dunce::canonicalize(program)
+            && let Some(home) = program.parent().and_then(Path::parent)
+        {
+            for conf in ["conf", "libexec/conf"] {
+                inputs.extend([home.join(conf).join("settings.xml"), home.join(conf).join("toolchains.xml")]);
+            }
+        }
+        if !environment.contains_key("JAVA_HOME") {
+            let java = process::program_path(if cfg!(windows) { "java.exe" } else { "java" }, &step.env);
+            inputs.push(java.clone());
+            if let Ok(java) = dunce::canonicalize(java)
+                && let Some(home) = java.parent().and_then(Path::parent)
+            {
+                inputs.push(home.join("release"));
+            }
+        }
+        for (i, arg) in step.args.iter().enumerate() {
+            if matches!(arg.as_str(), "-s" | "--settings" | "-gs" | "--global-settings" | "-t" | "--toolchains")
+                && let Some(file) = step.args.get(i + 1)
+            {
+                inputs.push(step.cwd.join(file));
+            }
+            for prefix in ["--settings=", "--global-settings=", "--toolchains="] {
+                if let Some(file) = arg.strip_prefix(prefix) {
+                    inputs.push(step.cwd.join(file));
+                }
+            }
+        }
+    }
+    if let Some(home) = dirs::home_dir() {
+        inputs.extend([home.join(".m2/settings.xml"), home.join(".m2/toolchains.xml")]);
+    }
+    for key in ["MAVEN_HOME", "M2_HOME"] {
+        if let Some(home) = environment.get(key) {
+            inputs.extend([Path::new(home).join("conf/settings.xml"), Path::new(home).join("conf/toolchains.xml")]);
+        }
+    }
+    if let Some(home) = environment.get("JAVA_HOME") {
+        inputs.extend([
+            Path::new(home).join("release"),
+            Path::new(home).join("lib/modules"),
+            Path::new(home).join("lib/tools.jar"),
+            Path::new(home).join(if cfg!(windows) { "bin/java.exe" } else { "bin/java" }),
+        ]);
+    }
+    let steps: Vec<_> =
+        plan.steps.iter().map(|s| (process::program_path(&s.program, &s.env), &s.args, &s.cwd, &s.env)).collect();
+    // Profiles and plugins can read arbitrary environment variables. Keep a signature
+    // of the inherited environment without persisting unrelated credentials.
+    let inherited: BTreeMap<_, _> = std::env::vars_os().collect();
+    let mut inherited_hash = std::hash::DefaultHasher::new();
+    inherited.hash(&mut inherited_hash);
+    let parameters =
+        serde_json::to_string(&(root, module, test, steps, environment, inherited_hash.finish(), projects))
+            .map_err(|e| IdeError::internal(e.to_string()))?;
+    let mut files = BTreeMap::new();
+    for path in inputs {
+        scan(&path, &mut files, &mut HashSet::new(), cancel)?;
+    }
+    // Store project inputs relative to the project, including each file's relative path.
+    let files = files.into_iter().map(|(p, stamp)| (p.strip_prefix(root).unwrap_or(&p).to_path_buf(), stamp)).collect();
+    Ok(Some(LaunchFingerprint { version: 1, parameters, files }))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn write(root: &Path, rel: &str, value: &str) {
+        let path = root.join(rel);
+        fs::create_dir_all(path.parent().unwrap()).unwrap();
+        fs::write(path, value).unwrap();
+    }
+
+    fn fixture(root: &Path) -> BuildModel {
+        write(
+            root,
+            "pom.xml",
+            r#"<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version>
+            <packaging>pom</packaging><modules><module>lib</module><module>app</module></modules></project>"#,
+        );
+        write(
+            root,
+            "lib/pom.xml",
+            r#"<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></parent>
+            <artifactId>lib</artifactId><build><sourceDirectory>code</sourceDirectory><resources><resource><directory>conf</directory></resource></resources></build></project>"#,
+        );
+        write(
+            root,
+            "app/pom.xml",
+            r#"<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></parent>
+            <artifactId>app</artifactId><dependencies><dependency><groupId>demo</groupId><artifactId>lib</artifactId><version>1</version></dependency></dependencies></project>"#,
+        );
+        write(root, "lib/src/main/kotlin/Channel.kt", "value");
+        write(root, "app/src/main/resources/app.properties", "key=value");
+        write(root, "lib/conf/custom.properties", "custom=value");
+        write(root, "lib/code/Custom.java", "class Custom {}");
+        BuildModel { maven: Some(maven::load(root)), ..Default::default() }
+    }
+
+    fn fingerprint(root: &Path, model: &BuildModel) -> Option<LaunchFingerprint> {
+        launch_fingerprint(root, model, &root.join("app"), false, None, &CancellationToken::new()).unwrap()
+    }
+
+    #[test]
+    fn unchanged_inputs_match_but_source_resource_pom_add_delete_and_mtime_invalidate() {
+        for rel in [
+            "lib/src/main/kotlin/Channel.kt",
+            "app/src/main/resources/app.properties",
+            "lib/conf/custom.properties",
+            "lib/code/Custom.java",
+            "app/pom.xml",
+            "lib/pom.xml",
+            "pom.xml",
+            ".mvn/maven.config",
+            "lib/src/main/groovy/New.groovy",
+            "app/src/test/scala/Test.scala",
+        ] {
+            let dir = tempfile::tempdir().unwrap();
+            let root = dir.path();
+            let model = fixture(root);
+            let before = fingerprint(root, &model);
+            assert!(before.is_some());
+            assert_eq!(before, fingerprint(root, &model), "unchanged {rel}");
+            let serialized = serde_json::to_vec(&before).unwrap();
+            assert_eq!(before, serde_json::from_slice(&serialized).unwrap());
+            let value = if rel.ends_with("pom.xml") {
+                format!("{}<!-- changed -->", fs::read_to_string(root.join(rel)).unwrap())
+            } else {
+                "changed input".to_owned()
+            };
+            write(root, rel, &value);
+            let changed = fingerprint(root, &model);
+            assert_ne!(before, changed, "changed/added {rel}");
+            let file = fs::OpenOptions::new().write(true).open(root.join(rel)).unwrap();
+            file.set_modified(SystemTime::UNIX_EPOCH + std::time::Duration::from_secs(42)).unwrap();
+            let touched = fingerprint(root, &model);
+            assert_ne!(changed, touched, "mtime-only {rel}");
+            fs::remove_file(root.join(rel)).unwrap();
+            assert_ne!(touched, fingerprint(root, &model), "deleted {rel}");
+        }
+    }
+
+    #[test]
+    fn profile_options_jdk_goal_and_wrapper_invalidate_without_using_class_outputs() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let mut model = fixture(root);
+        let before = fingerprint(root, &model);
+        write(root, "lib/target/classes/Channel.class", "JDT stub");
+        write(root, "app/target/classes/Main.class", "JDT stub");
+        assert_eq!(before, fingerprint(root, &model));
+        let mut previous = before.clone();
+        for option in ["-Pdev", "-Pprod", "-DskipTests", "-o"] {
+            model.maven.as_mut().unwrap().projects[0].options = vec![option.into()];
+            let current = fingerprint(root, &model);
+            assert_ne!(previous, current, "{option}");
+            previous = current;
+        }
+        model.maven.as_mut().unwrap().projects[0].options.clear();
+        model.maven.as_mut().unwrap().projects[0]
+            .env
+            .insert("JAVA_HOME".into(), root.join("jdk").to_string_lossy().into_owned());
+        let jdk = fingerprint(root, &model);
+        assert_ne!(before, jdk);
+        write(root, "jdk/release", "JAVA_VERSION=21");
+        assert_ne!(jdk, fingerprint(root, &model));
+        model.maven.as_mut().unwrap().projects[0].env.clear();
+        let test = launch_fingerprint(root, &model, &root.join("app"), true, None, &CancellationToken::new())
+            .unwrap()
+            .unwrap();
+        assert_ne!(before, Some(test));
+        write(root, "mvnw", "wrapper changed");
+        assert_ne!(before, fingerprint(root, &model));
+    }
+
+    #[test]
+    fn unresolved_roots_and_cancel_never_claim_up_to_date() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        write(
+            root,
+            "lib/pom.xml",
+            "<project><artifactId>lib</artifactId><build><sourceDirectory>${unknown}/src</sourceDirectory></build></project>",
+        );
+        assert!(
+            launch_fingerprint(root, &model, &root.join("app"), false, None, &CancellationToken::new())
+                .unwrap()
+                .is_none()
+        );
+        let model = fixture(root);
+        let cancel = CancellationToken::new();
+        cancel.cancel();
+        assert!(launch_fingerprint(root, &model, &root.join("app"), false, None, &cancel).is_err());
+    }
+    #[test]
+    fn external_parent_and_selected_settings_files_invalidate() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path().join("project");
+        let repo = dir.path().join("repository");
+        write(
+            &repo,
+            "demo/parent/1/parent-1.pom",
+            "<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></project>",
+        );
+        write(
+            &root,
+            "pom.xml",
+            "<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version><relativePath/></parent><artifactId>app</artifactId></project>",
+        );
+        let mut model = crate::load(&root, &root.join("cache"), Some(repo.clone()));
+        let settings = dir.path().join("custom-settings.xml");
+        fs::write(&settings, "<settings/>").unwrap();
+        model.maven.as_mut().unwrap().projects[0].options = vec!["-s".into(), settings.to_string_lossy().into_owned()];
+        let get =
+            || launch_fingerprint(&root, &model, &root, false, Some(repo.clone()), &CancellationToken::new()).unwrap();
+        let before = get();
+        assert!(before.is_some());
+        write(
+            &repo,
+            "demo/parent/1/parent-1.pom",
+            "<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version><!-- changed --></project>",
+        );
+        let parent = get();
+        assert_ne!(before, parent);
+        fs::write(settings, "<settings><activeProfiles><activeProfile>dev</activeProfile></activeProfiles></settings>")
+            .unwrap();
+        assert_ne!(parent, get());
+    }
+}
@@ -3,8 +3,11 @@
 //! background with cancellation and parses the compiler output into messages
 //! for the Build tool window, the Problems view and the editor.

+mod fingerprint;
 mod parse;

+pub use fingerprint::{LaunchFingerprint, launch_fingerprint};
+
 use crate::process::{self, Stream};
 use crate::{BuildModel, maven};
 use ide_core::{CancellationToken, Diagnostic, IdeError, IdeResult, Pos, Range, Severity};
@@ -237,12 +240,7 @@ fn maven_steps(root: &Path, model: &BuildModel, kind: BuildKind, module: Option<
    if !m.projects.iter().any(|p| p.dir == rel) {
        return Err(IdeError::not_found("no linked Maven project found for module"));
    }
-    let top = tops
-        .iter()
-        .filter(|t| t.dir.is_empty() || rel == t.dir || rel.starts_with(&format!("{}/", t.dir)))
-        .max_by_key(|t| t.dir.len())
-        .copied()
-        .unwrap_or(tops[0]);
+    let top = maven_reactor(m, &rel).ok_or_else(|| IdeError::not_found("no linked Maven project found for module"))?;
    let top_dir = subdir(root, &top.dir);
    if module == top_dir {
        return Ok(vec![step(top, &[])]);
@@ -611,6 +609,90 @@ pub fn has_non_java_sources(module: &Path) -> bool {
    walk(&module.join("src"), 12)
 }

+fn reactor_projects<'a>(m: &'a maven::MavenModel, top: &'a maven::MavenProject) -> Vec<&'a maven::MavenProject> {
+    let mut projects = Vec::new();
+    let mut pending = vec![top];
+    let mut seen = HashSet::new();
+    while let Some(p) = pending.pop() {
+        if !seen.insert(&p.pom) {
+            continue;
+        }
+        projects.push(p);
+        pending.extend(m.projects.iter().filter(|child| p.modules.contains(&child.pom)));
+    }
+    projects
+}
+
+fn maven_reactor<'a>(m: &'a maven::MavenModel, module: &str) -> Option<&'a maven::MavenProject> {
+    m.projects.iter().filter(|p| !p.aggregated).find(|top| reactor_projects(m, top).iter().any(|p| p.dir == module))
+}
+
+/// Launch module first, followed by its upstream modules in the same Maven reactor.
+/// External artifacts and unrelated linked reactors are never rebuilt for this launch.
+fn maven_launch_projects<'a>(
+    root: &Path,
+    m: &'a maven::MavenModel,
+    module: &Path,
+    test: bool,
+) -> Vec<&'a maven::MavenProject> {
+    let rel = rel_str(root, module);
+    let Some(top) = maven_reactor(m, &rel) else { return Vec::new() };
+    let reactor = reactor_projects(m, top);
+    let Some(start) = reactor.iter().find(|p| p.dir == rel) else { return Vec::new() };
+    let mut pending = vec![*start];
+    let mut seen = HashSet::new();
+    let mut projects = Vec::new();
+    while let Some(p) = pending.pop() {
+        if !seen.insert(&p.pom) {
+            continue;
+        }
+        projects.push(p);
+        for dep in &p.dependencies {
+            if !dep.resolved() || (dep.scope == "test" && (!test || p.pom != start.pom)) {
+                continue;
+            }
+            if let Some(upstream) = reactor.iter().find(|u| {
+                u.group_id == dep.group_id
+                    && u.artifact_id == dep.artifact_id
+                    && dep.version.as_ref().is_none_or(|v| *v == u.version)
+            }) {
+                pending.push(*upstream);
+            }
+        }
+    }
+    projects
+}
+
+/// Whether a launch requires the external JVM compiler. Maven includes upstream
+/// reactor dependencies; adapter selection remains a separate, module-local decision.
+pub fn launch_has_non_java_sources(root: &Path, model: &BuildModel, module: &Path, test: bool) -> bool {
+    if let Some(m) = &model.maven {
+        let projects = maven_launch_projects(root, m, module, test);
+        if !projects.is_empty() {
+            return projects.iter().any(|p| has_non_java_sources(&subdir(root, &p.dir)));
+        }
+    }
+    has_non_java_sources(module)
+}
+
+fn launch_plan(root: &Path, model: &BuildModel, module: &Path, test: bool) -> IdeResult<BuildPlan> {
+    let kind = if model.maven.as_ref().is_some_and(|m| m.projects.iter().any(|p| subdir(root, &p.dir) == module)) {
+        // JDT may have left newer error stubs in Maven's output directories.
+        BuildKind::Rebuild
+    } else {
+        BuildKind::Build
+    };
+    let mut plan = plan(root, model, kind, Some(module))?;
+    if plan.system == BuildSystem::Maven && !test {
+        for step in &mut plan.steps {
+            if let Some(goal) = step.args.last_mut() {
+                *goal = "compile".into();
+            }
+        }
+    }
+    Ok(plan)
+}
+
 /// Compiles the module at `module` with its build system before a JVM launch and
 /// returns the class directories it wrote, to put ahead of the jdtls classpath.
 pub fn build_for_launch(
@@ -620,7 +702,7 @@ pub fn build_for_launch(
    test: bool,
    cancel: &CancellationToken,
 ) -> IdeResult<Vec<PathBuf>> {
-    let plan = plan(root, model, BuildKind::Build, Some(module))?;
+    let plan = launch_plan(root, model, module, test)?;
    let result = run(root, &plan, cancel, &|_| {})?;
    if !result.success {
        let errors: Vec<String> = result
@@ -635,6 +717,14 @@ pub fn build_for_launch(
            .collect();
        return Err(IdeError::internal(format!("Build failed:\n{}", errors.join("\n"))));
    }
+    if plan.system == BuildSystem::Maven
+        && let Some(m) = &model.maven
+    {
+        return Ok(maven_launch_projects(root, m, module, test)
+            .iter()
+            .flat_map(|p| launch_class_dirs(plan.system, &subdir(root, &p.dir), test && subdir(root, &p.dir) == module))
+            .collect());
+    }
    Ok(launch_class_dirs(plan.system, module, test))
 }

@@ -821,6 +911,142 @@ mod tests {
        }
    }

+    fn reactor_model() -> BuildModel {
+        let project = |dir: &str, deps: &[&str]| maven::MavenProject {
+            pom: format!("{dir}/pom.xml"),
+            dir: dir.into(),
+            group_id: "probe".into(),
+            artifact_id: dir.into(),
+            version: "1".into(),
+            aggregated: true,
+            dependencies: deps
+                .iter()
+                .map(|d| maven::MavenDependency {
+                    group_id: "probe".into(),
+                    artifact_id: (*d).into(),
+                    version: Some("1".into()),
+                    scope: "compile".into(),
+                    ..Default::default()
+                })
+                .collect(),
+            ..Default::default()
+        };
+        let mut projects = vec![
+            project("app", &["middle"]),
+            project("middle", &["lib"]),
+            project("lib", &["app"]),
+            project("unrelated", &[]),
+        ];
+        projects.insert(
+            0,
+            maven::MavenProject {
+                pom: "pom.xml".into(),
+                artifact_id: "reactor".into(),
+                command: "mvnw".into(),
+                modules: projects.iter().map(|p| p.pom.clone()).collect(),
+                options: vec!["-s".into(), "settings.xml".into()],
+                env: BTreeMap::from([("JAVA_HOME".into(), "/jdk".into())]),
+                ..Default::default()
+            },
+        );
+        BuildModel { maven: Some(maven::MavenModel { projects, ..Default::default() }), ..Default::default() }
+    }
+
+    #[test]
+    fn mixed_launch_detection_follows_only_reactor_dependencies() {
+        for extension in ["kt", "groovy", "scala"] {
+            let tmp = tempfile::tempdir().unwrap();
+            let root = tmp.path();
+            let mut model = reactor_model();
+            write(root, "app/src/main/java/Application.java", "class Application {}");
+            write(root, &format!("unrelated/src/main/java/Other.{extension}"), "");
+            assert!(!launch_has_non_java_sources(root, &model, &root.join("app"), false));
+            write(root, &format!("lib/src/main/java/Channel.{extension}"), "");
+            assert!(launch_has_non_java_sources(root, &model, &root.join("app"), false));
+            assert_eq!(
+                maven_launch_projects(root, model.maven.as_ref().unwrap(), &root.join("app"), false).len(),
+                3,
+                "cycles terminate"
+            );
+            let m = model.maven.as_mut().unwrap();
+            m.projects[2].dependencies[0].scope = "test".into();
+            assert!(
+                !launch_has_non_java_sources(root, &model, &root.join("app"), true),
+                "upstream test dependencies are not transitive"
+            );
+            let m = model.maven.as_mut().unwrap();
+            m.projects[1].dependencies[0].scope = "test".into();
+            m.projects[2].dependencies[0].scope = "compile".into();
+            assert!(!launch_has_non_java_sources(root, &model, &root.join("app"), false));
+            assert!(launch_has_non_java_sources(root, &model, &root.join("app"), true));
+            model.maven.as_mut().unwrap().projects[2].dependencies[0].version = Some("external".into());
+            assert!(!launch_has_non_java_sources(root, &model, &root.join("app"), true));
+            model.maven.as_mut().unwrap().projects[2].dependencies[0].version = Some("1".into());
+            model.maven.as_mut().unwrap().projects[3].aggregated = false;
+            model.maven.as_mut().unwrap().projects[0].modules.retain(|p| p != "lib/pom.xml");
+            assert!(
+                !launch_has_non_java_sources(root, &model, &root.join("app"), true),
+                "another linked reactor is external"
+            );
+        }
+    }
+
+    #[test]
+    fn maven_launch_steps_use_reactor_settings_and_launch_scope() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(root, "app/pom.xml", "<project/>");
+        let model = reactor_model();
+        for (test, goal) in [(false, "compile"), (true, "test-compile")] {
+            let plan = launch_plan(root, &model, &root.join("app"), test).unwrap();
+            let step = &plan.steps[0];
+            assert_eq!(step.cwd, root);
+            assert_eq!(step.program, "mvnw");
+            assert_eq!(step.env["JAVA_HOME"], "/jdk");
+            assert_eq!(
+                step.args,
+                ["-B", "-Dstyle.color=never", "-s", "settings.xml", "-pl", "app", "-am", "clean", goal]
+            );
+        }
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn external_launch_returns_upstream_outputs_and_blocks_failure_or_cancellation() {
+        use std::os::unix::fs::PermissionsExt;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(root, "app/pom.xml", "<project/>");
+        write(
+            root,
+            "mvnw",
+            "#!/bin/sh\nmkdir -p app/target/classes middle/target/classes lib/target/classes app/target/test-classes\n",
+        );
+        let wrapper = root.join("mvnw");
+        std::fs::set_permissions(&wrapper, std::fs::Permissions::from_mode(0o755)).unwrap();
+        let mut model = reactor_model();
+        model.maven.as_mut().unwrap().projects[0].command = wrapper.to_string_lossy().into_owned();
+        let dirs = build_for_launch(root, &model, &root.join("app"), true, &CancellationToken::new()).unwrap();
+        assert_eq!(
+            dirs,
+            ["app/target/test-classes", "app/target/classes", "middle/target/classes", "lib/target/classes"]
+                .map(|p| root.join(p))
+        );
+        write(
+            root,
+            "mvnw",
+            "#!/bin/sh\necho '[ERROR] Kotlin compilation failed: unresolved reference broken' >&2\nexit 1\n",
+        );
+        let error = build_for_launch(root, &model, &root.join("app"), false, &CancellationToken::new()).unwrap_err();
+        assert!(error.message.contains("Kotlin compilation failed"), "{}", error.message);
+        let cancel = CancellationToken::new();
+        cancel.cancel();
+        assert_eq!(
+            build_for_launch(root, &model, &root.join("app"), false, &cancel).unwrap_err().kind,
+            ide_core::error::ErrorKind::Cancelled
+        );
+    }
+
    #[test]
    fn non_java_launch_class_dirs() {
        let tmp = tempfile::tempdir().unwrap();
@@ -0,0 +1,475 @@
+//! Private Maven builds for JDT's Kotlin binary libraries. Never use launch outputs.
+
+use crate::BuildModel;
+use crate::compile::{self, BuildEvent, BuildKind, BuildMessage};
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeMap;
+use std::path::{Path, PathBuf};
+
+#[derive(Clone, Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct Module {
+    key: String,
+    project_uri: String,
+    output: PathBuf,
+    test_output: Option<PathBuf>,
+    dependencies: Vec<Dependency>,
+    has_kotlin: bool,
+    kotlin_goals: Vec<KotlinGoal>,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+struct KotlinGoal {
+    execution: String,
+    status: String,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+struct Dependency {
+    key: String,
+    scope: String,
+    #[serde(rename = "type")]
+    kind: Option<String>,
+    classifier: Option<String>,
+}
+
+#[derive(Clone, Debug, Serialize, PartialEq, Eq)]
+pub struct Library {
+    pub path: PathBuf,
+    pub test: bool,
+}
+
+#[derive(Clone, Debug, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub struct ProjectLibraries {
+    pub project_uri: String,
+    pub libraries: Vec<Library>,
+}
+
+pub struct Outcome {
+    pub projects: Vec<ProjectLibraries>,
+    pub messages: Vec<BuildMessage>,
+    pub success: bool,
+}
+
+/// Inspect sources, excluding generated/build/VCS trees and never following symlinks.
+pub fn has_kotlin(root: &Path) -> bool {
+    let Ok(entries) = std::fs::read_dir(root) else { return false };
+    entries.flatten().any(|entry| {
+        let Ok(kind) = entry.file_type() else { return false };
+        if kind.is_file() {
+            entry.path().extension().is_some_and(|e| e == "kt")
+        } else {
+            kind.is_dir()
+                && !matches!(
+                    entry.file_name().to_str(),
+                    Some("target" | "build" | "out" | "bin" | "node_modules" | ".git" | ".openidea")
+                )
+                && has_kotlin(&entry.path())
+        }
+    })
+}
+
+/// Run the project's configured wrapper/settings/JDK and lifecycle, with an output
+/// redirector loaded before Maven calculates its lifecycle execution plans.
+pub fn build(
+    root: &Path,
+    model: &BuildModel,
+    bundle: &Path,
+    generation: &Path,
+    cancel: &CancellationToken,
+) -> IdeResult<Outcome> {
+    std::fs::create_dir_all(generation)?;
+    let mut plan = compile::plan(root, model, BuildKind::Build, None)?;
+    if plan.system != compile::BuildSystem::Maven {
+        return Err(IdeError::invalid("Kotlin bridge requires a Maven build root"));
+    }
+    let mut manifests = Vec::new();
+    for (index, step) in plan.steps.iter_mut().enumerate() {
+        step.args.push("--fail-at-end".into());
+        let directory = generation.join(format!("reactor-{index}"));
+        std::fs::create_dir_all(&directory)?;
+        manifests.push(directory.join("modules.json"));
+        let mut extensions = vec![bundle.to_path_buf()];
+        step.args.retain(|arg| {
+            if let Some(value) = arg.strip_prefix("-Dmaven.ext.class.path=") {
+                extensions.extend(std::env::split_paths(value));
+                false
+            } else {
+                true
+            }
+        });
+        let extension_path = std::env::join_paths(extensions).map_err(|e| IdeError::invalid(e.to_string()))?;
+        step.args.push(format!("-Dmaven.ext.class.path={}", extension_path.to_string_lossy()));
+        step.args.push(format!("-Dopenidea.kotlin.staging={}", directory.join("staging").display()));
+    }
+    let mut messages = Vec::new();
+    // Independent linked reactors must still run after another reactor's javac fails.
+    for step in &plan.steps {
+        let mut reactor = plan.clone();
+        reactor.steps = vec![step.clone()];
+        let result = compile::run(root, &reactor, cancel, &|event| {
+            if let BuildEvent::Output { text, .. } = event {
+                tracing::debug!("kotlin bridge: {}", text.trim_end());
+            }
+        })?;
+        messages.extend(result.messages);
+    }
+    // javac diagnostics belong to JDT, including when a Kotlin target was skipped.
+    messages.retain(|message| {
+        message.path.as_ref().is_some_and(|path| PathBuf::from(path.clone()).extension().is_some_and(|e| e == "kt"))
+    });
+    let mut modules = Vec::new();
+    for manifest in manifests {
+        let parsed: Vec<Module> = serde_json::from_slice(&std::fs::read(manifest)?)
+            .map_err(|e| IdeError::internal(format!("Kotlin module manifest: {e}")))?;
+        modules.extend(parsed);
+    }
+    messages.extend(kotlin_failures(&modules));
+    if messages.iter().any(|message| message.severity == ide_core::Severity::Error) {
+        return Ok(Outcome { projects: Vec::new(), messages, success: false });
+    }
+    let pending = generation.join("libraries.pending");
+    let published = generation.join("libraries");
+    std::fs::create_dir_all(&pending)?;
+    let mut libraries = BTreeMap::new();
+    for (index, module) in modules.iter().enumerate() {
+        let mut outputs = ModuleLibraries::default();
+        for (source, target, name) in [
+            (Some(&module.output), &mut outputs.main, format!("main-{index}")),
+            (module.test_output.as_ref(), &mut outputs.test, format!("test-{index}")),
+        ] {
+            let Some(source) = source else { continue };
+            if !source.starts_with(generation) {
+                return Err(IdeError::internal("Kotlin build output escaped staging"));
+            }
+            if copy_kotlin(source, &pending.join(&name), cancel)? {
+                *target = Some(published.join(name));
+            }
+        }
+        libraries.insert(module.key.clone(), outputs);
+    }
+    publish(&pending, &published, cancel)?;
+    Ok(Outcome { projects: consumers(&modules, &libraries), messages, success: true })
+}
+
+fn kotlin_failures(modules: &[Module]) -> Vec<BuildMessage> {
+    let mut messages = Vec::new();
+    for module in modules {
+        if !module.has_kotlin {
+            continue;
+        }
+        if module.kotlin_goals.is_empty() {
+            messages.push(kotlin_failure(module, "compile target was not executed"));
+        }
+        for goal in &module.kotlin_goals {
+            if goal.status != "success" {
+                messages.push(kotlin_failure(module, &format!("{} {}", goal.execution, goal.status)));
+            }
+        }
+    }
+    messages
+}
+
+fn kotlin_failure(module: &Module, reason: &str) -> BuildMessage {
+    BuildMessage {
+        severity: ide_core::Severity::Error,
+        text: format!("Kotlin compilation for {}: {reason}", module.key),
+        path: None,
+        range: None,
+        code: None,
+    }
+}
+
+fn publish(pending: &Path, published: &Path, cancel: &CancellationToken) -> IdeResult<()> {
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    std::fs::rename(pending, published)?;
+    Ok(())
+}
+
+#[derive(Default)]
+struct ModuleLibraries {
+    main: Option<PathBuf>,
+    test: Option<PathBuf>,
+}
+
+fn consumers(modules: &[Module], libraries: &BTreeMap<String, ModuleLibraries>) -> Vec<ProjectLibraries> {
+    modules
+        .iter()
+        .map(|consumer| {
+            let mut visible = Vec::<Library>::new();
+            let mut add = |path: &Option<PathBuf>, test: bool| {
+                if let Some(path) = path {
+                    if let Some(previous) = visible.iter_mut().find(|entry| &entry.path == path) {
+                        previous.test &= test;
+                    } else {
+                        visible.push(Library { path: path.clone(), test });
+                    }
+                }
+            };
+            if let Some(own) = libraries.get(&consumer.key) {
+                add(&own.test, true);
+                add(&own.main, false);
+            }
+            // Maven's resolved artifacts already apply exclusions, mediation and optional
+            // propagation. Preserve their classpath order, after the module's own output.
+            for dependency in &consumer.dependencies {
+                let Some(output) = libraries.get(&dependency.key) else { continue };
+                let test = match dependency.scope.as_str() {
+                    "compile" | "provided" | "system" | "" => false,
+                    "test" | "runtime" => true,
+                    _ => continue,
+                };
+                match (dependency.kind.as_deref(), dependency.classifier.as_deref()) {
+                    (Some("test-jar"), None | Some("tests")) | (Some("jar"), Some("tests")) => add(&output.test, test),
+                    (None | Some("jar"), None | Some("")) => add(&output.main, test),
+                    _ => {}
+                }
+            }
+            ProjectLibraries { project_uri: consumer.project_uri.clone(), libraries: visible }
+        })
+        .collect()
+}
+
+fn copy_kotlin(source: &Path, destination: &Path, cancel: &CancellationToken) -> IdeResult<bool> {
+    let Ok(entries) = std::fs::read_dir(source) else { return Ok(false) };
+    let mut found = false;
+    for entry in entries {
+        if cancel.is_cancelled() {
+            return Err(IdeError::cancelled());
+        }
+        let entry = entry?;
+        let kind = entry.file_type()?;
+        let path = entry.path();
+        let output = destination.join(entry.file_name());
+        if kind.is_dir() {
+            found |= copy_kotlin(&path, &output, cancel)?;
+        } else if kind.is_file() {
+            let bytes = std::fs::read(&path)?;
+            let class = path.extension().is_some_and(|e| e == "class");
+            let metadata = path.extension().is_some_and(|e| e == "kotlin_module");
+            if metadata || (class && kotlin_class(&bytes).unwrap_or(false)) {
+                std::fs::create_dir_all(destination)?;
+                std::fs::write(output, bytes)?;
+                found |= class;
+            }
+        }
+    }
+    Ok(found)
+}
+
+/// Read the actual class-level SourceFile attribute, rather than searching strings
+/// (a Java constant containing "Something.kt" must never become a Kotlin library).
+fn kotlin_class(bytes: &[u8]) -> Option<bool> {
+    struct Reader<'a> {
+        bytes: &'a [u8],
+        pos: usize,
+    }
+    impl<'a> Reader<'a> {
+        fn take(&mut self, count: usize) -> Option<&'a [u8]> {
+            let value = self.bytes.get(self.pos..self.pos.checked_add(count)?)?;
+            self.pos += count;
+            Some(value)
+        }
+        fn u2(&mut self) -> Option<usize> {
+            Some(u16::from_be_bytes(self.take(2)?.try_into().ok()?) as usize)
+        }
+        fn u4(&mut self) -> Option<usize> {
+            Some(u32::from_be_bytes(self.take(4)?.try_into().ok()?) as usize)
+        }
+        fn attributes(&mut self) -> Option<()> {
+            for _ in 0..self.u2()? {
+                self.u2()?;
+                let n = self.u4()?;
+                self.take(n)?;
+            }
+            Some(())
+        }
+    }
+    let mut reader = Reader { bytes, pos: 0 };
+    if reader.take(4)? != [0xca, 0xfe, 0xba, 0xbe] {
+        return None;
+    }
+    reader.take(4)?;
+    let count = reader.u2()?;
+    let mut utf8 = BTreeMap::new();
+    let mut index = 1;
+    while index < count {
+        match reader.take(1)?[0] {
+            1 => {
+                let n = reader.u2()?;
+                utf8.insert(index, reader.take(n)?);
+            }
+            3 | 4 | 9..=12 | 17 | 18 => {
+                reader.take(4)?;
+            }
+            5 | 6 => {
+                reader.take(8)?;
+                index += 1;
+            }
+            7 | 8 | 16 | 19 | 20 => {
+                reader.take(2)?;
+            }
+            15 => {
+                reader.take(3)?;
+            }
+            _ => return None,
+        }
+        index += 1;
+    }
+    reader.take(6)?;
+    let interfaces = reader.u2()?;
+    reader.take(interfaces.checked_mul(2)?)?;
+    for _ in 0..2 {
+        for _ in 0..reader.u2()? {
+            reader.take(6)?;
+            reader.attributes()?;
+        }
+    }
+    for _ in 0..reader.u2()? {
+        let name = reader.u2()?;
+        let length = reader.u4()?;
+        if utf8.get(&name).copied() == Some(b"SourceFile".as_slice()) && length == 2 {
+            let source = reader.u2()?;
+            return Some(utf8.get(&source)?.ends_with(b".kt"));
+        }
+        reader.take(length)?;
+    }
+    Some(false)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn every_kotlin_target_must_succeed_even_when_maven_fails_elsewhere() {
+        let mut modules: Vec<Module> = serde_json::from_str(r#"[
+            {"key":"lib","projectUri":"lib","output":"lib","dependencies":[],"hasKotlin":true,
+             "kotlinGoals":[{"execution":"main:compile","status":"success"},{"execution":"test:test-compile","status":"success"}]},
+            {"key":"java","projectUri":"java","output":"java","dependencies":[],"hasKotlin":false,"kotlinGoals":[]}
+        ]"#).unwrap();
+        assert!(kotlin_failures(&modules).is_empty());
+        for status in ["failed", "skipped"] {
+            modules[0].kotlin_goals[1].status = status.into();
+            let failures = kotlin_failures(&modules);
+            assert_eq!(failures.len(), 1);
+            assert!(failures[0].text.contains(&format!("test:test-compile {status}")));
+        }
+        modules[0].kotlin_goals.clear();
+        assert_eq!(kotlin_failures(&modules).len(), 1);
+        modules[0].has_kotlin = false;
+        assert!(kotlin_failures(&modules).is_empty());
+        assert!(
+            serde_json::from_str::<Vec<Module>>(
+                r#"[{"key":"old","projectUri":"old","output":"old","dependencies":[]}]"#
+            )
+            .is_err()
+        );
+    }
+
+    #[test]
+    fn respects_mavens_resolved_closure_and_scopes() {
+        let json = r#"[
+          {"key":"zapp","projectUri":"app","output":"app", "hasKotlin":false,"kotlinGoals":[],"dependencies":[{"key":"mid","scope":"compile","optional":false},{"key":"lib","scope":"compile","optional":false}]},
+          {"key":"mid","projectUri":"mid","output":"mid", "hasKotlin":false,"kotlinGoals":[],"dependencies":[
+            {"key":"lib","scope":"compile","optional":false},
+            {"key":"optional","scope":"compile","optional":true},
+            {"key":"test","scope":"test","optional":false},
+            {"key":"provided","scope":"provided","optional":false}]},
+          {"key":"lib","projectUri":"lib","output":"lib","hasKotlin":false,"kotlinGoals":[],"dependencies":[]}
+        ]"#;
+        let modules: Vec<Module> = serde_json::from_str(json).unwrap();
+        let libraries = ["zapp", "lib", "optional", "test", "provided"]
+            .into_iter()
+            .map(|key| (key.to_owned(), ModuleLibraries { main: Some(PathBuf::from(key)), test: None }))
+            .collect();
+        let result = consumers(&modules, &libraries);
+        assert_eq!(
+            result[0].libraries,
+            vec![Library { path: "zapp".into(), test: false }, Library { path: "lib".into(), test: false },]
+        );
+        assert_eq!(result[1].libraries.len(), 4);
+        assert!(result[1].libraries.iter().find(|l| l.path == Path::new("test")).unwrap().test);
+    }
+
+    #[test]
+    fn test_outputs_are_private_unless_maven_resolves_a_test_jar() {
+        let modules: Vec<Module> = serde_json::from_str(r#"[
+          {"key":"lib","projectUri":"lib","output":"lib","hasKotlin":false,"kotlinGoals":[],"dependencies":[]},
+          {"key":"app","projectUri":"app","output":"app","hasKotlin":false,"kotlinGoals":[],"dependencies":[{"key":"lib","scope":"compile","type":"jar","classifier":null}]},
+          {"key":"test-app","projectUri":"test-app","output":"app","hasKotlin":false,"kotlinGoals":[],"dependencies":[{"key":"lib","scope":"test","type":"test-jar","classifier":"tests"}]}
+        ]"#).unwrap();
+        let libraries =
+            BTreeMap::from([("lib".into(), ModuleLibraries { main: Some("main".into()), test: Some("test".into()) })]);
+        let result = consumers(&modules, &libraries);
+        assert_eq!(
+            result[0].libraries,
+            vec![Library { path: "test".into(), test: true }, Library { path: "main".into(), test: false }]
+        );
+        assert_eq!(result[1].libraries, vec![Library { path: "main".into(), test: false }]);
+        assert_eq!(result[2].libraries, vec![Library { path: "test".into(), test: true }]);
+    }
+
+    #[test]
+    fn publishes_complete_directories_and_cancellation_keeps_them_private() {
+        let directory = tempfile::tempdir().unwrap();
+        let pending = directory.path().join("pending");
+        let final_path = directory.path().join("published");
+        std::fs::create_dir(&pending).unwrap();
+        std::fs::write(pending.join("Channel.class"), "complete").unwrap();
+        let cancelled = CancellationToken::new();
+        cancelled.cancel();
+        assert!(publish(&pending, &final_path, &cancelled).is_err());
+        assert!(!final_path.exists());
+        assert!(pending.exists());
+        publish(&pending, &final_path, &CancellationToken::new()).unwrap();
+        assert!(!pending.exists());
+        assert_eq!(std::fs::read(final_path.join("Channel.class")).unwrap(), b"complete");
+    }
+
+    #[test]
+    fn never_runs_another_build_system_with_maven_output_properties() {
+        let directory = tempfile::tempdir().unwrap();
+        std::fs::write(directory.path().join("Cargo.toml"), "").unwrap();
+        let error = build(
+            directory.path(),
+            &BuildModel::default(),
+            Path::new("unused.jar"),
+            &directory.path().join("private"),
+            &CancellationToken::new(),
+        )
+        .err()
+        .unwrap();
+        assert_eq!(error.message, "Kotlin bridge requires a Maven build root");
+    }
+
+    #[test]
+    fn does_not_find_deleted_sources_in_build_outputs() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::create_dir_all(dir.path().join("target/generated")).unwrap();
+        std::fs::write(dir.path().join("target/generated/Old.kt"), "").unwrap();
+        assert!(!has_kotlin(dir.path()));
+        std::fs::write(dir.path().join("New.kt"), "").unwrap();
+        assert!(has_kotlin(dir.path()));
+    }
+
+    #[test]
+    fn parses_sourcefile_and_rejects_truncated_classes() {
+        let mut class = vec![0xca, 0xfe, 0xba, 0xbe, 0, 0, 0, 52, 0, 3, 1, 0, 10];
+        class.extend_from_slice(b"SourceFile");
+        class.extend_from_slice(&[1, 0, 10]);
+        class.extend_from_slice(b"Channel.kt");
+        class.extend_from_slice(&[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 2, 0, 2]);
+        assert_eq!(kotlin_class(&class), Some(true));
+        for end in 0..class.len() {
+            assert!(kotlin_class(&class[..end]).is_none());
+        }
+        let offset = 26;
+        class[offset..offset + 10].copy_from_slice(b"Other.java");
+        assert_eq!(kotlin_class(&class), Some(false));
+    }
+}
@@ -5,8 +5,10 @@
 //! and merges what the last sync ([`sync_maven`] / [`sync_gradle`], which run
 //! Maven / Gradle in the background) cached for the project.

+pub mod application_update;
 pub mod compile;
 pub mod gradle;
+pub mod kotlin_bridge;
 pub mod maven;
 pub mod pom_edit;
 mod process;
@@ -601,6 +601,72 @@ impl Resolver {
    }
 }

+/// Files and source/resource trees consumed by a launch build. Unresolved custom
+/// roots disable reuse rather than silently omitting an input.
+pub(crate) fn launch_inputs(
+    root: &Path,
+    projects: &[&MavenProject],
+    local_repo: Option<PathBuf>,
+) -> Option<Vec<PathBuf>> {
+    fn roots(el: &Element, parent: &str, dir: &Path, out: &mut Vec<PathBuf>) -> Option<()> {
+        let input =
+            matches!(el.name.as_str(), "sourceDirectory" | "testSourceDirectory" | "sourceDir" | "testSourceDir")
+                || (matches!(parent, "sources" | "sourceDirs" | "testSources" | "testSourceDirs")
+                    && matches!(el.name.as_str(), "source" | "sourceDir" | "testSourceDir"))
+                || (matches!(parent, "resource" | "testResource" | "source" | "testSource") && el.name == "directory")
+                || (parent == "filters" && el.name == "filter");
+        // Profile activation may depend on the presence of an otherwise unrelated file.
+        let activation = parent == "file" && matches!(el.name.as_str(), "exists" | "missing");
+        if input || activation {
+            // Other properties can be overridden by -D, profiles or settings.
+            // Without Maven's effective roots, conservatively disable reuse for them.
+            let value = el
+                .text
+                .trim()
+                .replace("${project.basedir}", &dir.to_string_lossy())
+                .replace("${basedir}", &dir.to_string_lossy());
+            if value.contains("${") {
+                return None;
+            }
+            if !value.is_empty() {
+                out.push(dir.join(value));
+            }
+        }
+        for child in &el.children {
+            roots(child, &el.name, dir, out)?;
+        }
+        Some(())
+    }
+    let mut resolver = Resolver::new(local_repo.or_else(default_local_repo));
+    let mut out = Vec::new();
+    for project in projects {
+        let dir = root.join(&project.dir);
+        // Include all conventional language/resource roots, including nonstandard files under src.
+        out.push(dir.join("src"));
+        let pom = root.join(&project.pom);
+        resolver.context(&pom, 0);
+        let mut path = pom;
+        let mut seen = HashSet::new();
+        loop {
+            let canonical = dunce::canonicalize(&path).ok()?;
+            if !seen.insert(canonical) || seen.len() > MAX_PARENT_DEPTH {
+                return None;
+            }
+            out.push(path.clone());
+            let text = std::fs::read_to_string(&path).ok()?;
+            roots(&xml::parse(&text)?, "", &dir, &mut out)?;
+            let raw = resolver.pom(&path)?;
+            let Some(parent) = raw.parent else { break };
+            path = resolver.parent_path(path.parent()?, &parent)?;
+        }
+    }
+    // Also track imported BOMs read while resolving inheritance.
+    out.extend(resolver.poms.into_keys());
+    out.sort();
+    out.dedup();
+    Some(out)
+}
+
 // ---------------------------------------------------------------- plugins

 /// `maven-clean-plugin` → `clean`, `spring-boot-maven-plugin` → `spring-boot`.
@@ -37,7 +37,7 @@ fn kill_tree(child: &mut Child) {
 /// `program` as spawnable: a bare name (`mvn`, `mvn.cmd`) resolves on the IDE's
 /// search path — the login shell's `PATH` plus version-manager shims — since the
 /// app's own `PATH` can be minimal and `Command` would not see `mvn` there.
-fn program_path(program: &str, env: &BTreeMap<String, String>) -> std::path::PathBuf {
+pub(crate) fn program_path(program: &str, env: &BTreeMap<String, String>) -> std::path::PathBuf {
    let path = std::path::Path::new(program);
    if !path.is_relative() || path.components().count() > 1 {
        return path.to_path_buf();
@@ -1,6 +1,8 @@
 //! The file list on the OS clipboard: what Explorer copies when the user
 //! copies files, so the project view can paste them, and what the project view
-//! writes so Explorer can paste the files it copied (IDEA does both).
+//! writes so Explorer can paste the files it copied (IDEA does both). The
+//! written list comes with the paths as text, so a paste into an editor
+//! inserts them instead of doing nothing.
 //!
 //! Windows keeps it as `CF_HDROP`: a `DROPFILES` header and a double-NUL
 //! terminated list of absolute paths, wide when `fWide` is set. The data is set
@@ -10,6 +12,9 @@
 //! macOS keeps one `public.file-url` item per file on the general
 //! `NSPasteboard`; `NSURL` reads and writes them, so Finder's copies paste here
 //! and ours paste in Finder.
+//! On macOS, [`files`], [`has_files`] and [`set_files`] must run on the main
+//! thread: AppKit and WebKit also access the general pasteboard there, and its
+//! mutable type cache cannot be protected by a mutex in this crate.
 //!
 //! Other platforms (`text/uri-list` on X11) are not wired up: [`files`] is
 //! empty and [`set_files`] fails there.
@@ -20,7 +25,8 @@ use std::path::PathBuf;
 const HEADER: usize = 20;

 /// The absolute paths on the clipboard, empty when it holds no file list.
-pub fn files() -> Vec<PathBuf> {
+/// Read failures remain errors so callers can retain an internal copy.
+pub fn files() -> std::io::Result<Vec<PathBuf>> {
    imp::files()
 }

@@ -29,9 +35,8 @@ pub fn has_files() -> bool {
    imp::has_files()
 }

-/// Replaces the clipboard with `paths`. False when it is busy or holds nothing
-/// to write; the clipboard is a shared resource, so callers treat this as
-/// best-effort.
+/// Replaces the clipboard with `paths`. True only when the file list was
+/// accepted; writing just the accompanying text is not a successful hand-off.
 pub fn set_files(paths: &[PathBuf]) -> bool {
    if paths.is_empty() {
        return false;
@@ -111,6 +116,8 @@ mod imp {

    /// `CF_HDROP`, the clipboard format holding a file list.
    const CF_HDROP: u32 = 15;
+    /// `CF_UNICODETEXT`, so an editor paste of copied files inserts the paths.
+    const CF_UNICODETEXT: u32 = 13;

    /// An `HGLOBAL` or a `HANDLE`: both are opaque pointers here.
    type Handle = *mut c_void;
@@ -156,25 +163,29 @@ mod imp {
        (unsafe { IsClipboardFormatAvailable(CF_HDROP) }) != 0
    }

-    pub fn files() -> Vec<PathBuf> {
-        if !has_files() || !open() {
-            return Vec::new();
+    pub fn files() -> std::io::Result<Vec<PathBuf>> {
+        if !open() {
+            return Err(std::io::Error::last_os_error());
+        }
+        if !has_files() {
+            unsafe { CloseClipboard() };
+            return Ok(Vec::new());
        }
        let memory = unsafe { GetClipboardData(CF_HDROP) };
        let paths = if memory.is_null() {
-            Vec::new()
+            Err(std::io::Error::last_os_error())
        } else {
            // SAFETY: the clipboard keeps the block alive while it is open, and
            // `GlobalSize` bounds the bytes read from it.
            unsafe {
                let data = GlobalLock(memory);
                if data.is_null() {
-                    Vec::new()
+                    Err(std::io::Error::last_os_error())
                } else {
                    let bytes = std::slice::from_raw_parts(data as *const u8, GlobalSize(memory));
                    let paths = decode(bytes);
                    GlobalUnlock(memory);
-                    paths
+                    Ok(paths)
                }
            }
        };
@@ -182,12 +193,37 @@ mod imp {
        paths
    }

+    /// An `HGLOBAL` holding `text` as UTF-16 with a terminating NUL, and its
+    /// byte size. Null when the allocation failed.
+    fn global_text(text: &str) -> (Handle, usize) {
+        let mut units: Vec<u16> = text.encode_utf16().collect();
+        units.push(0);
+        let bytes = units.len() * 2;
+        unsafe {
+            let memory = GlobalAlloc(GMEM_MOVEABLE, bytes);
+            if memory.is_null() {
+                return (ptr::null_mut(), 0);
+            }
+            let data = GlobalLock(memory);
+            if data.is_null() {
+                GlobalFree(memory);
+                return (ptr::null_mut(), 0);
+            }
+            ptr::copy_nonoverlapping(units.as_ptr() as *const u8, data as *mut u8, bytes);
+            GlobalUnlock(memory);
+            (memory, bytes)
+        }
+    }
+
    pub fn set_files(paths: &[PathBuf]) -> bool {
        let bytes = encode(paths);
        if bytes.len() <= HEADER {
            return false;
        }
-        // SAFETY: the block is allocated, filled, handed to the clipboard and
+        // The paths as text, newline-separated, so pasting into an editor
+        // inserts them (IDEA writes the list and the text together).
+        let text = paths.iter().map(|p| p.to_string_lossy().into_owned()).collect::<Vec<_>>().join("\r\n");
+        // SAFETY: the blocks are allocated, filled, handed to the clipboard and
        // freed only on the paths where the clipboard did not take ownership.
        unsafe {
            let memory = GlobalAlloc(GMEM_MOVEABLE, bytes.len());
@@ -205,17 +241,26 @@ mod imp {
                GlobalFree(memory);
                return false;
            }
-            // Replacing the list also drops the text the user copied before.
+            // Replacing the list also drops the text the user copied before;
+            // the paths' own text is set back with it.
            if EmptyClipboard() == 0 {
                CloseClipboard();
                GlobalFree(memory);
                return false;
            }
            let taken = !SetClipboardData(CF_HDROP, memory).is_null();
-            CloseClipboard();
            if !taken {
                GlobalFree(memory);
            }
+            let (text_memory, _) = global_text(&text);
+            if !text_memory.is_null() {
+                // The text alone still pastes somewhere useful.
+                let text_taken = !SetClipboardData(CF_UNICODETEXT, text_memory).is_null();
+                if !text_taken {
+                    GlobalFree(text_memory);
+                }
+            }
+            CloseClipboard();
            taken
        }
    }
@@ -223,13 +268,14 @@ mod imp {

 #[cfg(target_os = "macos")]
 mod imp {
-    use objc2::ClassType;
    use objc2::rc::{Retained, autoreleasepool};
    use objc2::runtime::{AnyClass, AnyObject, ProtocolObject};
+    use objc2::{ClassType, MainThreadMarker};
    use objc2_app_kit::{
-        NSPasteboard, NSPasteboardReadingOptionKey, NSPasteboardURLReadingFileURLsOnlyKey, NSPasteboardWriting,
+        NSPasteboard, NSPasteboardReadingOptionKey, NSPasteboardTypeString, NSPasteboardURLReadingFileURLsOnlyKey,
+        NSPasteboardWriting,
    };
-    use objc2_foundation::{NSArray, NSDictionary, NSNumber, NSURL};
+    use objc2_foundation::{NSArray, NSDictionary, NSNumber, NSString, NSURL};
    use std::path::PathBuf;

    /// `NSURL` as the one class to read, limited to file URLs: a web link the
@@ -237,6 +283,7 @@ mod imp {
    fn read_file_urls<R>(
        f: impl FnOnce(&NSPasteboard, &NSArray<AnyClass>, &NSDictionary<NSPasteboardReadingOptionKey, AnyObject>) -> R,
    ) -> R {
+        debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
        autoreleasepool(|_| {
            let board = NSPasteboard::generalPasteboard();
            let classes = NSArray::from_slice(&[NSURL::class()]);
@@ -256,23 +303,28 @@ mod imp {
        })
    }

-    pub fn files() -> Vec<PathBuf> {
+    pub fn files() -> std::io::Result<Vec<PathBuf>> {
        read_file_urls(|board, classes, options| {
            // SAFETY: as in `has_files`; every object read for `NSURL` is one.
            let Some(objects) = (unsafe { board.readObjectsForClasses_options(classes, Some(options)) }) else {
-                return Vec::new();
+                return if unsafe { board.canReadObjectForClasses_options(classes, Some(options)) } {
+                    Err(std::io::Error::other("Cannot read clipboard files"))
+                } else {
+                    Ok(Vec::new())
+                };
            };
-            objects
+            Ok(objects
                .iter()
                .filter_map(|object| object.downcast::<NSURL>().ok())
                .filter_map(|url| url.to_file_path())
                // Finder ends a folder's URL in `/`; the project view names it without.
                .map(|path| path.components().collect())
-                .collect()
+                .collect())
        })
    }

    pub fn set_files(paths: &[PathBuf]) -> bool {
+        debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
        autoreleasepool(|_| {
            // Folders get a directory URL (ending in `/`), as Finder writes them.
            let urls: Vec<Retained<NSURL>> = paths
@@ -285,9 +337,16 @@ mod imp {
            let writers: Vec<&ProtocolObject<dyn NSPasteboardWriting>> =
                urls.iter().map(|url| ProtocolObject::from_ref(&**url)).collect();
            let board = NSPasteboard::generalPasteboard();
-            // Replacing the list also drops the text the user copied before.
+            // Replacing the list also drops the text the user copied before;
+            // the paths' own text is set back with it, so an editor paste
+            // inserts them (IDEA writes the list and the text together).
            board.clearContents();
-            board.writeObjects(&NSArray::from_slice(&writers))
+            let written = board.writeObjects(&NSArray::from_slice(&writers));
+            let text = NSString::from_str(
+                &paths.iter().map(|p| p.to_string_lossy().into_owned()).collect::<Vec<_>>().join("\n"),
+            );
+            board.setString_forType(&text, unsafe { NSPasteboardTypeString });
+            written
        })
    }
 }
@@ -300,8 +359,8 @@ mod imp {
        false
    }

-    pub fn files() -> Vec<PathBuf> {
-        Vec::new()
+    pub fn files() -> std::io::Result<Vec<PathBuf>> {
+        Ok(Vec::new())
    }

    pub fn set_files(_paths: &[PathBuf]) -> bool {
@@ -371,6 +371,12 @@ pub struct TextAttributesOverride {
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct LanguageCodeStyle {
+    /// Java formatter: `default` | `intellij` | `custom` (other languages ignore it).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub formatter: Option<String>,
+    /// Eclipse formatter XML; relative paths start at the project root.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub formatter_path: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub use_tab: Option<bool>,
    #[serde(skip_serializing_if = "Option::is_none")]
@@ -12,6 +12,15 @@ pub type IdeResult<T> = Result<T, IdeError>;
 pub struct IdeError {
    pub kind: ErrorKind,
    pub message: String,
+    /// Structured detail for errors the UI acts on; `null` for plain errors.
+    #[specta(optional)]
+    pub data: Option<ErrorData>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(tag = "type", rename_all = "camelCase")]
+pub enum ErrorData {
+    Tool { tool: String, missing: bool },
 }

 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
@@ -24,6 +33,7 @@ pub enum ErrorKind {
    /// Document version mismatch; the UI must resync the full text.
    OutOfSync,
    Cancelled,
+    TimedOut,
    /// A required external tool (language server, git, debugger) is unavailable.
    Unavailable,
    Io,
@@ -33,7 +43,21 @@ pub enum ErrorKind {

 impl IdeError {
    pub fn new(kind: ErrorKind, message: impl Into<String>) -> Self {
-        Self { kind, message: message.into() }
+        Self { kind, message: message.into(), data: None }
+    }
+    pub fn with_tool(mut self, tool: impl Into<String>) -> Self {
+        if self.data.is_none() {
+            self.data = Some(ErrorData::Tool { tool: tool.into(), missing: false });
+        }
+        self
+    }
+    pub fn missing_tool(tool: impl Into<String>) -> Self {
+        let tool = tool.into();
+        Self {
+            kind: ErrorKind::NotFound,
+            message: format!("{tool} is not installed"),
+            data: Some(ErrorData::Tool { tool, missing: true }),
+        }
    }
    pub fn not_found(m: impl Into<String>) -> Self {
        Self::new(ErrorKind::NotFound, m)
@@ -65,3 +89,30 @@ impl From<std::io::Error> for IdeError {
        Self::new(kind, e.to_string())
    }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn tool_errors_round_trip_without_changing_diagnostics() {
+        let message = "[error] file.css: Unexpected token\n  1 | }\n";
+        let error = IdeError::invalid(message).with_tool("prettier");
+        let decoded: IdeError = serde_json::from_str(&serde_json::to_string(&error).unwrap()).unwrap();
+        assert_eq!(decoded.message, message);
+        assert_eq!(decoded.data, Some(ErrorData::Tool { tool: "prettier".into(), missing: false }));
+        let missing = IdeError::missing_tool("prettier").with_tool("prettier");
+        assert_eq!(missing.kind, ErrorKind::NotFound);
+        assert_eq!(missing.data, Some(ErrorData::Tool { tool: "prettier".into(), missing: true }));
+    }
+
+    #[test]
+    fn legacy_errors_need_no_data() {
+        let error: IdeError = serde_json::from_str(r#"{"kind":"unavailable","message":"no server"}"#).unwrap();
+        assert!(error.data.is_none());
+        assert_eq!(
+            serde_json::to_value(error).unwrap(),
+            serde_json::json!({"kind":"unavailable","message":"no server","data":null})
+        );
+    }
+}
@@ -215,13 +215,21 @@ fn fix_kind(
 }

 /// `vmArgs` of a launch by java-debug, which decodes the JVM's output as `encoding`
-/// (its launch attribute, UTF-8 when unset) and sets `file.encoding` itself.
-pub fn java_debug_vm_args(vm_args: &str, encoding: Option<&str>, windows: bool) -> Option<String> {
+/// (its launch attribute, UTF-8 when unset). java-debug sets `file.encoding` only
+/// when that attribute is nonblank; use the same defaults and user overrides as [`fix`].
+pub fn java_debug_vm_args(
+    vm_args: &str,
+    vars: &BTreeMap<String, String>,
+    inherited: impl Fn(&str) -> Option<String>,
+    encoding: Option<&str>,
+    windows: bool,
+) -> Option<String> {
    let encoding = encoding.map(str::trim).filter(|e| !e.is_empty()).unwrap_or("UTF-8");
-    if (!windows && is_utf8(encoding)) || sets(vm_args, STD_PROPERTIES) {
+    let added = fix_kind(Kind::Java, Some(&[vm_args.to_owned()]), vars, inherited, encoding, windows).java_args;
+    if added.is_empty() {
        return None;
    }
-    let added = options(STD_PROPERTIES, encoding).join(" ");
+    let added = added.join(" ");
    Some(match vm_args.trim() {
        "" => added,
        own => format!("{own} {added}"),
@@ -446,12 +454,53 @@ mod tests {

    #[test]
    fn java_debug_launches_write_what_java_debug_decodes() {
-        assert_eq!(java_debug_vm_args("", None, true).as_deref(), Some(TOOL_UTF8));
-        assert_eq!(java_debug_vm_args("-Xmx1g", Some(""), true), Some(format!("-Xmx1g {TOOL_UTF8}")));
-        assert_eq!(java_debug_vm_args("", Some("GBK"), true).unwrap().split(' ').next(), Some("-Dstdout.encoding=GBK"));
-        assert_eq!(java_debug_vm_args("-Dstdout.encoding=GBK", None, true), None);
-        assert_eq!(java_debug_vm_args("-Xmx1g", None, false), None);
-        assert!(java_debug_vm_args("", Some("GBK"), false).is_some());
+        let debug =
+            |args: &str, encoding, windows| java_debug_vm_args(args, &BTreeMap::new(), |_| None, encoding, windows);
+        for encoding in [None, Some(""), Some("  "), Some("UTF-8"), Some("utf8")] {
+            let streams = encoding.filter(|e| !e.trim().is_empty()).unwrap_or("UTF-8");
+            let utf8 = format!("{} -Dfile.encoding=UTF-8", options(STD_PROPERTIES, streams).join(" "));
+            assert_eq!(debug("", encoding, true), Some(utf8.clone()));
+            assert_eq!(debug("-Xmx1g", encoding, true), Some(format!("-Xmx1g {utf8}")));
+            assert_eq!(debug("-Xmx1g", encoding, false), None);
+        }
+        for windows in [true, false] {
+            assert_eq!(debug("", Some("GBK"), windows), Some(options(STD_PROPERTIES, "GBK").join(" ")));
+        }
+    }
+
+    #[test]
+    fn java_debug_preserves_user_options_independently() {
+        let debug = |args: &str| java_debug_vm_args(args, &BTreeMap::new(), |_| None, None, true);
+        assert_eq!(debug("-Dfile.encoding=GBK"), Some(format!("-Dfile.encoding=GBK {TOOL_UTF8}")));
+        for property in STD_PROPERTIES {
+            let args = format!("-D{property}=GBK");
+            assert_eq!(debug(&args), Some(format!("{args} -Dfile.encoding=UTF-8")));
+            assert_eq!(debug(&format!("{args} -Dfile.encoding=GBK")), None);
+        }
+        for key in ["JDK_JAVA_OPTIONS", TOOL_OPTIONS] {
+            for (own, expected) in [
+                ("-Dfile.encoding=GBK", Some(TOOL_UTF8.to_owned())),
+                ("-Dstdout.encoding=GBK", Some("-Dfile.encoding=UTF-8".to_owned())),
+                ("-Dstdout.encoding=GBK -Dfile.encoding=GBK", None),
+            ] {
+                assert_eq!(java_debug_vm_args("", &vars(&[(key, own)]), |_| None, None, true), expected);
+                assert_eq!(
+                    java_debug_vm_args("", &BTreeMap::new(), |k| (k == key).then(|| own.to_owned()), None, true),
+                    expected
+                );
+            }
+            // A launch environment value overrides the inherited one, as in Run.
+            assert_eq!(
+                java_debug_vm_args(
+                    "",
+                    &vars(&[(key, "")]),
+                    |k| (k == key).then(|| "-Dfile.encoding=GBK".into()),
+                    None,
+                    true
+                ),
+                Some(format!("{TOOL_UTF8} -Dfile.encoding=UTF-8"))
+            );
+        }
    }

    fn filtered(chunks: &[&str]) -> String {
@@ -276,6 +276,8 @@ pub struct AppearanceSettings {
    /// Apply `ui_font_family` / `ui_font_size` (otherwise the theme's).
    pub use_custom_font: bool,
    pub ui_font_family: String,
+    /// Font tried when `ui_font_family` lacks a glyph; empty = none.
+    pub ui_font_fallback: String,
    pub contrast_scrollbars: bool,
    /// Adjust colours for red-green vision deficiency.
    pub red_green_vision: bool,
@@ -292,6 +294,7 @@ pub struct AppearanceSettings {
    pub editor_antialiasing: String,
    pub show_tool_window_bars: bool,
    pub show_tool_window_names: bool,
+    pub show_tool_window_badges: bool,
    pub widescreen_tool_windows: bool,
    /// Status bar widgets shown (`true`) or hidden (`false`) by the user
    /// (status bar context menu); widgets not listed use their default.
@@ -325,6 +328,7 @@ impl Default for AppearanceSettings {
            zoom: 100,
            use_custom_font: false,
            ui_font_family: "Inter".into(),
+            ui_font_fallback: String::new(),
            contrast_scrollbars: false,
            red_green_vision: false,
            different_tool_window_background: false,
@@ -338,6 +342,7 @@ impl Default for AppearanceSettings {
            editor_antialiasing: "greyscale".into(),
            show_tool_window_bars: true,
            show_tool_window_names: false,
+            show_tool_window_badges: true,
            widescreen_tool_windows: false,
            status_bar_widgets: BTreeMap::new(),
            main_toolbar: None,
@@ -503,9 +508,50 @@ pub struct LanguagesSettings {
    pub rust: RustSettings,
    pub go: GoSettings,
    pub typescript: TypeScriptSettings,
+    pub prettier: PrettierSettings,
    pub java: JavaSettings,
 }

+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct PrettierSettings {
+    /// Empty path: project node_modules, managed installation, then PATH.
+    pub path: String,
+    pub languages: Vec<String>,
+    /// Prefer Prettier even when a language server offers formatting.
+    pub prefer: bool,
+    pub run_on_save: bool,
+}
+
+impl Default for PrettierSettings {
+    fn default() -> Self {
+        Self {
+            path: String::new(),
+            languages: [
+                "markdown",
+                "yaml",
+                "css",
+                "scss",
+                "less",
+                "html",
+                "graphql",
+                "javascript",
+                "javascriptreact",
+                "typescript",
+                "typescriptreact",
+                "json",
+                "jsonc",
+                "vue",
+            ]
+            .into_iter()
+            .map(String::from)
+            .collect(),
+            prefer: false,
+            run_on_save: false,
+        }
+    }
+}
+
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct PythonSettings {
@@ -719,6 +765,35 @@ impl Settings {
 mod tests {
    use super::*;

+    #[test]
+    fn ui_font_fallback_defaults_empty_and_round_trips() {
+        let old: Settings = serde_json::from_str(r#"{"appearance":{"useCustomFont":true}}"#).unwrap();
+        assert!(old.appearance.ui_font_fallback.is_empty());
+        for family in ["", "Songti SC", "Maple Mono NF CN"] {
+            let mut settings = Settings::default();
+            settings.appearance.ui_font_fallback = family.into();
+            let json = serde_json::to_value(&settings).unwrap();
+            assert_eq!(json["appearance"]["uiFontFallback"], family);
+            let restored: Settings = serde_json::from_value(json).unwrap();
+            assert_eq!(restored.appearance.ui_font_fallback, family);
+        }
+    }
+
+    #[test]
+    fn tool_window_badges_default_on_and_round_trip() {
+        let old: Settings = serde_json::from_str(r#"{"appearance":{"showToolWindowNames":true}}"#).unwrap();
+        assert!(old.appearance.show_tool_window_badges);
+        assert!(Settings::default().appearance.show_tool_window_badges);
+        for enabled in [false, true] {
+            let mut settings = Settings::default();
+            settings.appearance.show_tool_window_badges = enabled;
+            let json = serde_json::to_value(&settings).unwrap();
+            assert_eq!(json["appearance"]["showToolWindowBadges"], enabled);
+            let restored: Settings = serde_json::from_value(json).unwrap();
+            assert_eq!(restored.appearance.show_tool_window_badges, enabled);
+        }
+    }
+
    #[test]
    fn main_menu_style_defaults_and_round_trips() {
        let old: Settings = serde_json::from_str(r#"{"appearance":{"compactMode":true}}"#).unwrap();
@@ -905,6 +905,7 @@ fn godot_registry(port: u16, command: &str, args: &[&str]) -> Arc<LanguageRegist
        indent: None,
        ui_mode: None,
        framework_ui_modes: Vec::new(),
+        formatter: None,
        tree_sitter: None,
        language_servers: vec![],
        debugger: Some(ide_language::DebuggerConfig {
@@ -7,10 +7,11 @@ license.workspace = true

 [dependencies]
 serde.workspace = true
+serde_json.workspace = true
 specta.workspace = true

 [target.'cfg(target_os = "macos")'.dependencies]
-objc2-core-foundation = { version = "0.3", default-features = false, features = ["std", "CFArray", "CFDictionary", "CFNumber", "CFString"] }
+objc2-core-foundation = { version = "0.3", default-features = false, features = ["std", "CFArray", "CFDictionary", "CFNumber", "CFString", "CFURL"] }
 objc2-core-text = { version = "0.3", default-features = false, features = ["std", "CTFontCollection", "CTFontDescriptor", "CTFontTraits"] }

 [target.'cfg(windows)'.dependencies]
@@ -1,8 +1,7 @@
 //! The font families installed on this machine, for the font pickers in
 //! Settings (editor, typography fallback, terminal, UI font).
 //!
-//! Each platform asks the font system the WebView itself resolves CSS
-//! `font-family` names against, so every listed name renders: CoreText on
+//! Each platform asks the native font system for installed families: CoreText on
 //! macOS, DirectWrite on Windows, fontconfig (`fc-list`) on Linux and the BSDs.
 //! The list is read on first use and cached until explicitly refreshed; the
 //! query can take a few hundred milliseconds, so callers run it off the UI and
@@ -84,14 +83,164 @@ pub fn parse_fc_list(output: &str) -> Vec<(String, bool)> {
        .collect()
 }

+/// Binary font bundle: little-endian u32 JSON-header length, a face metadata
+/// array, then raw font bytes. Paths never cross IPC; only CoreText-enumerated
+/// files under user font directories can be read, selected by family name.
+/// Includes only the nearest regular/bold faces and their optional italics.
+pub fn user_font_data(family: &str) -> std::io::Result<Vec<u8>> {
+    #[cfg(target_os = "macos")]
+    {
+        let entries = imp::user_faces();
+        bundle_family(family, &entries)
+    }
+    #[cfg(not(target_os = "macos"))]
+    {
+        let _ = family;
+        Err(std::io::Error::new(std::io::ErrorKind::Unsupported, "User font loading is macOS only"))
+    }
+}
+
+#[cfg(any(target_os = "macos", test))]
+#[derive(Debug)]
+struct UserFace {
+    family: String,
+    path: std::path::PathBuf,
+    weight: u16,
+    italic: bool,
+}
+
+#[cfg(any(target_os = "macos", test))]
+fn user_font_path(path: &std::path::Path, roots: &[std::path::PathBuf]) -> Option<std::path::PathBuf> {
+    let path = path.canonicalize().ok()?;
+    roots.iter().any(|root| path.starts_with(root)).then_some(path)
+}
+
+#[cfg(any(target_os = "macos", test))]
+fn family_faces<'a>(family: &str, entries: &'a [UserFace]) -> Vec<&'a UserFace> {
+    let mut selected: Vec<&UserFace> = Vec::new();
+    for italic in [false, true] {
+        for weight in [400u16, 700] {
+            let closest = entries
+                .iter()
+                .filter(|e| e.family.eq_ignore_ascii_case(family.trim()) && e.italic == italic)
+                .min_by_key(|e| (e.weight.abs_diff(weight), e.weight, &e.path));
+            if let Some(face) = closest
+                && !selected.iter().any(|f| std::ptr::eq(*f, face))
+            {
+                selected.push(face);
+            }
+        }
+    }
+    selected
+}
+
+#[cfg(any(target_os = "macos", test))]
+fn bundle_family(family: &str, entries: &[UserFace]) -> std::io::Result<Vec<u8>> {
+    #[derive(Serialize)]
+    struct Face {
+        weight: u16,
+        style: &'static str,
+        offset: usize,
+        length: usize,
+    }
+    let mut faces = Vec::new();
+    let mut data = Vec::new();
+    let mut files = BTreeMap::new();
+    // Bound large CJK families to regular/bold and their nearest italic faces.
+    for entry in family_faces(family, entries) {
+        // Reject a file replaced by a symlink after enumeration.
+        if entry.path.canonicalize()? != entry.path {
+            return Err(std::io::Error::new(std::io::ErrorKind::PermissionDenied, "Font file changed"));
+        }
+        let (offset, length) = if let Some(range) = files.get(&entry.path) {
+            *range
+        } else {
+            let bytes = std::fs::read(&entry.path)?;
+            let range = (data.len(), bytes.len());
+            data.extend(bytes);
+            files.insert(entry.path.clone(), range);
+            range
+        };
+        faces.push(Face {
+            weight: entry.weight,
+            style: if entry.italic { "italic" } else { "normal" },
+            offset,
+            length,
+        });
+    }
+    if faces.is_empty() {
+        return Err(std::io::Error::new(std::io::ErrorKind::NotFound, "No installed user font family"));
+    }
+    let header = serde_json::to_vec(&faces)?;
+    let mut out = (header.len() as u32).to_le_bytes().to_vec();
+    out.extend(header);
+    out.extend(data);
+    Ok(out)
+}
+
 #[cfg(target_os = "macos")]
 mod imp {
-    use objc2_core_foundation::{CFArray, CFDictionary, CFNumber, CFString, CFType};
+    use objc2_core_foundation::{CFArray, CFDictionary, CFNumber, CFString, CFType, CFURL};
    use objc2_core_text::{
        CTFontCollection, CTFontDescriptor, CTFontSymbolicTraits, kCTFontFamilyNameAttribute, kCTFontSymbolicTrait,
-        kCTFontTraitsAttribute,
+        kCTFontTraitsAttribute, kCTFontURLAttribute, kCTFontWeightTrait,
    };

+    pub(crate) fn user_faces() -> Vec<super::UserFace> {
+        let mut roots = vec![std::path::PathBuf::from("/Library/Fonts")];
+        if let Some(home) = std::env::var_os("HOME") {
+            roots.push(std::path::PathBuf::from(home).join("Library/Fonts"));
+        }
+        let roots: Vec<_> = roots.into_iter().filter_map(|r| r.canonicalize().ok()).collect();
+        // SAFETY: CoreText descriptors carry documented CFString, CFURL and trait dictionary values.
+        unsafe {
+            let collection = CTFontCollection::from_available_fonts(None);
+            let Some(descriptors) = collection.matching_font_descriptors() else { return Vec::new() };
+            let mut seen = std::collections::BTreeSet::new();
+            descriptors
+                .cast_unchecked::<CTFontDescriptor>()
+                .iter()
+                .filter_map(|d| {
+                    let family = d.attribute(kCTFontFamilyNameAttribute)?.downcast::<CFString>().ok()?.to_string();
+                    let path = d.attribute(kCTFontURLAttribute)?.downcast::<CFURL>().ok()?.to_file_path()?;
+                    let path = super::user_font_path(&path, &roots)?;
+                    let traits = d.attribute(kCTFontTraitsAttribute)?.downcast::<CFDictionary>().ok()?;
+                    let traits = traits.cast_unchecked::<CFString, CFType>();
+                    let symbolic = traits
+                        .get(kCTFontSymbolicTrait)
+                        .and_then(|n| n.downcast::<CFNumber>().ok())
+                        .and_then(|n| n.as_i64())
+                        .unwrap_or(0) as u32;
+                    let weight = traits
+                        .get(kCTFontWeightTrait)
+                        .and_then(|n| n.downcast::<CFNumber>().ok())
+                        .and_then(|n| n.as_f64())
+                        .unwrap_or(0.0);
+                    // CoreText's normalized weight values corresponding to CSS's nine standard weights.
+                    let weight = [
+                        (-0.8, 100),
+                        (-0.6, 200),
+                        (-0.4, 300),
+                        (0.0, 400),
+                        (0.23, 500),
+                        (0.3, 600),
+                        (0.4, 700),
+                        (0.56, 800),
+                        (0.62, 900),
+                    ]
+                    .into_iter()
+                    .min_by(|(a, _), (b, _)| (weight - a).abs().total_cmp(&(weight - b).abs()))?
+                    .1;
+                    let italic = symbolic & CTFontSymbolicTraits::TraitItalic.0 != 0;
+                    if !seen.insert((family.clone(), path.clone(), weight, italic)) {
+                        return None;
+                    }
+                    Some(super::UserFace { family, path, weight, italic })
+                })
+                .collect()
+        }
+    }
+
    /// Every face CoreText makes available to this process, as (family, fixed pitch).
    pub(crate) fn list(_refresh: bool) -> Vec<(String, bool)> {
        // SAFETY: CoreText's documented types: the matching descriptors array
@@ -210,6 +359,92 @@ mod tests {
    use super::*;
    use std::sync::atomic::{AtomicUsize, Ordering};

+    #[test]
+    fn selects_only_regular_bold_and_matching_italics_from_dense_families() {
+        let entries: Vec<_> = [false, true]
+            .into_iter()
+            .flat_map(|italic| {
+                (100..=900).step_by(100).map(move |weight| UserFace {
+                    family: "CJK".into(),
+                    path: format!("{weight}-{italic}.ttf").into(),
+                    weight,
+                    italic,
+                })
+            })
+            .collect();
+        let selected = family_faces(" cjk ", &entries);
+        assert_eq!(
+            selected.iter().map(|f| (f.weight, f.italic)).collect::<Vec<_>>(),
+            [(400, false), (700, false), (400, true), (700, true),]
+        );
+        assert!(family_faces("unknown", &entries).is_empty());
+    }
+
+    #[test]
+    fn selects_nearest_available_weights_once_with_optional_italics() {
+        let entries: Vec<_> = [(300, false), (500, false), (800, false), (500, true)]
+            .into_iter()
+            .map(|(weight, italic)| UserFace {
+                family: "Sparse".into(),
+                path: format!("{weight}-{italic}.ttf").into(),
+                weight,
+                italic,
+            })
+            .collect();
+        let selected = family_faces("Sparse", &entries);
+        assert_eq!(
+            selected.iter().map(|f| (f.weight, f.italic)).collect::<Vec<_>>(),
+            [(300, false), (800, false), (500, true),]
+        );
+        assert_eq!(family_faces("Sparse", &entries[..1]).len(), 1);
+    }
+
+    #[test]
+    fn bundle_only_reads_enumerated_family_faces() {
+        let root = std::env::current_dir().unwrap().join(format!("../../.font-bundle-test-{}", std::process::id()));
+        std::fs::create_dir_all(&root).unwrap();
+        let root = root.canonicalize().unwrap();
+        let regular = root.join("regular.ttf");
+        let bold = root.join("bold.ttf");
+        std::fs::write(&regular, [1, 2, 3]).unwrap();
+        std::fs::write(&bold, [4, 5]).unwrap();
+        let entries = [
+            UserFace { family: "Test Nerd Font".into(), path: regular.clone(), weight: 400, italic: false },
+            UserFace { family: "Test Nerd Font".into(), path: bold, weight: 700, italic: false },
+            // A non-selected face is never opened, even if its file has disappeared.
+            UserFace { family: "Test Nerd Font".into(), path: root.join("thin.ttf"), weight: 100, italic: false },
+        ];
+        let result = bundle_family("test nerd font", &entries).unwrap();
+        let len = u32::from_le_bytes(result[..4].try_into().unwrap()) as usize;
+        let faces: serde_json::Value = serde_json::from_slice(&result[4..4 + len]).unwrap();
+        assert_eq!(faces[0]["weight"], 400);
+        assert_eq!(faces[1]["weight"], 700);
+        assert_eq!(faces.as_array().unwrap().len(), 2);
+        assert_eq!(&result[4 + len..], &[1, 2, 3, 4, 5]);
+        // Existing files are not inputs: neither paths nor unenumerated families grant access.
+        assert!(bundle_family(regular.to_str().unwrap(), &entries).is_err());
+        assert!(bundle_family("Unenumerated", &entries).is_err());
+        assert!(user_font_path(&regular, &[]).is_none());
+        assert!(user_font_path(&regular, std::slice::from_ref(&root)).is_some());
+        // Multiple selected descriptors in a collection still transfer the file only once.
+        let shared = [
+            UserFace { family: "Collection".into(), path: regular.clone(), weight: 400, italic: false },
+            UserFace { family: "Collection".into(), path: regular, weight: 700, italic: false },
+        ];
+        let result = bundle_family("Collection", &shared).unwrap();
+        let len = u32::from_le_bytes(result[..4].try_into().unwrap()) as usize;
+        let faces: serde_json::Value = serde_json::from_slice(&result[4..4 + len]).unwrap();
+        assert_eq!(faces[0]["offset"], faces[1]["offset"]);
+        assert_eq!(&result[4 + len..], &[1, 2, 3]);
+        #[cfg(unix)]
+        {
+            let link = root.join("outside.ttf");
+            std::os::unix::fs::symlink(std::env::current_exe().unwrap(), &link).unwrap();
+            assert!(user_font_path(&link, std::slice::from_ref(&root)).is_none());
+        }
+        std::fs::remove_dir_all(root).unwrap();
+    }
+
    fn fam(name: &str, monospaced: bool) -> FontFamily {
        FontFamily { name: name.into(), monospaced }
    }
@@ -48,7 +48,7 @@ parking_lot.workspace = true
 dunce.workspace = true
 dirs.workspace = true
 uuid.workspace = true
+tempfile.workspace = true

 [dev-dependencies]
 tokio = { workspace = true, features = ["rt-multi-thread", "macros", "io-util", "test-util"] }
-tempfile.workspace = true
@@ -0,0 +1,107 @@
+//! Select the document's formatting provider before executing it on this host.
+
+use crate::Host;
+use ide_core::event::NotifyLevel;
+use ide_core::settings::PrettierSettings;
+use ide_core::{DocId, IdeError, IdeEvent, IdeResult, Range, TextEdit};
+use ide_language::FormatterConfig;
+use ide_lsp::types::FormatOptions;
+use ide_tools::{Tools, formatter};
+
+fn external_selected(config: Option<&FormatterConfig>, language: &str, settings: &PrettierSettings, lsp: bool) -> bool {
+    config.is_some_and(|c| c.tool == "prettier")
+        && settings.languages.iter().any(|l| l == language)
+        && (settings.prefer || !lsp)
+}
+
+pub async fn format(
+    host: &Host,
+    window: &str,
+    doc: DocId,
+    range: Option<Range>,
+    options: FormatOptions,
+) -> IdeResult<Vec<TextEdit>> {
+    let project = host.project(window)?;
+    let snap = project.documents.snapshot(doc)?;
+    let settings = project.settings.effective();
+    let prettier = &settings.languages.prettier;
+    let language = project.languages.get(&snap.language);
+    let config = language.as_ref().and_then(|l| l.formatter.as_ref());
+    let candidate =
+        config.is_some_and(|c| c.tool == "prettier") && prettier.languages.iter().any(|l| l == snap.language.as_str());
+    let lsp = if candidate && !prettier.prefer { project.lsp.can_format(doc).await? } else { false };
+    if !external_selected(config, snap.language.as_str(), prettier, lsp) {
+        if options.on_save && !settings.editor.format_on_save {
+            return Ok(Vec::new());
+        }
+        return project.lsp.format(doc, range, options).await;
+    }
+    if options.on_save && !prettier.run_on_save {
+        return Ok(Vec::new());
+    }
+    host.require_trust(window)?;
+    if snap.read_only {
+        return Err(IdeError::invalid("The file is read-only"));
+    }
+    let config = config.unwrap().clone();
+    let custom = ide_sdk::apply::setting_path(&project.root, &prettier.path);
+    let tools = Tools::new(&host.data_dir);
+    let whole_selection = range.is_some() && !config.range;
+    let edits: IdeResult<Vec<TextEdit>> = tokio::task::spawn_blocking(move || {
+        let text = ide_text::Document::new(&snap.text);
+        let offsets = range.map(|r| (text.pos_to_offset(r.start), text.pos_to_offset(r.end)));
+        let mut command = tools.formatter_command(&config.tool, &snap.path, custom.as_deref())?;
+        command.current_dir(snap.path.parent().ok_or_else(|| IdeError::invalid("Prettier: file has no directory"))?);
+        command.args(formatter::arguments(&config, &snap.path, options.tab_size, options.insert_spaces, offsets));
+        let formatted = formatter::run(command, &snap.text, &Default::default())?;
+        Ok(text
+            .diff(&formatted)
+            .changes
+            .into_iter()
+            .map(|c| TextEdit {
+                range: Range::new(text.offset_to_pos(c.from), text.offset_to_pos(c.to)),
+                new_text: c.insert,
+            })
+            .collect())
+    })
+    .await
+    .map_err(|e| IdeError::internal(e.to_string()))?;
+    if edits.is_ok() && whole_selection {
+        project.sink.emit(IdeEvent::Notify {
+            level: NotifyLevel::Info,
+            title: "Prettier".into(),
+            body: Some(
+                "Prettier does not support selection formatting for this language; formatted the whole file".into(),
+            ),
+        });
+    }
+    edits.map_err(|e| e.with_tool("prettier"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn language_enablement_and_preference_preserve_lsp_formatters() {
+        let languages = ide_language::LanguageRegistry::load(None).unwrap();
+        let mut settings = PrettierSettings::default();
+        for lang in languages.all() {
+            for lsp in [false, true] {
+                let configured = lang.formatter.as_ref().is_some_and(|f| f.tool == "prettier");
+                assert_eq!(
+                    external_selected(lang.formatter.as_ref(), lang.id.as_str(), &settings, lsp),
+                    configured && !lsp,
+                    "{}",
+                    lang.id
+                );
+            }
+        }
+        let ts = languages.get(&ide_core::LanguageId::new("typescript")).unwrap();
+        settings.prefer = true;
+        assert!(external_selected(ts.formatter.as_ref(), "typescript", &settings, true));
+        settings.languages.clear();
+        assert!(!external_selected(ts.formatter.as_ref(), "typescript", &settings, false));
+        assert!(!external_selected(None, "rust", &settings, false));
+    }
+}
@@ -0,0 +1,429 @@
+//! Saved Kotlin -> isolated Maven output -> marked JDT libraries.
+
+use ide_build::kotlin_bridge::{self, Outcome, ProjectLibraries};
+use ide_core::event::NotifyLevel;
+use ide_core::{CancellationToken, Diagnostic, IdeEvent, Pos, Range, Severity, SharedSink};
+use ide_lsp::LspManager;
+use ide_workspace::SettingsStore;
+use ide_workspace::documents::DocumentObserver;
+use parking_lot::Mutex;
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeSet;
+use std::path::{Path, PathBuf};
+use std::sync::{
+    Arc,
+    atomic::{AtomicBool, Ordering},
+};
+use std::time::Duration;
+use tokio::sync::Notify;
+
+const DELAY: Duration = Duration::from_millis(750);
+const SOURCE: &str = "kotlin-bridge";
+const COMMAND: &str = "openidea.kotlin.replace";
+
+#[derive(Default)]
+struct Revision {
+    generation: u64,
+    cancel: CancellationToken,
+}
+
+impl Revision {
+    fn change(&mut self) {
+        self.cancel.cancel();
+        self.generation += 1;
+        self.cancel = CancellationToken::new();
+    }
+    fn current(&self, generation: u64) -> bool {
+        self.generation == generation && !self.cancel.is_cancelled()
+    }
+}
+
+#[derive(Clone, Default, Serialize, Deserialize)]
+struct MavenOptions {
+    offline: bool,
+    profiles: Vec<String>,
+}
+
+pub(crate) struct KotlinBridge {
+    root: PathBuf,
+    cache: PathBuf,
+    bundle: Option<PathBuf>,
+    settings: Arc<SettingsStore>,
+    lsp: Arc<LspManager>,
+    sink: SharedSink,
+    trusted: Arc<AtomicBool>,
+    lifetime: CancellationToken,
+    revision: Mutex<Revision>,
+    changed: Notify,
+    options: Mutex<MavenOptions>,
+    worker: Mutex<Option<tokio::task::JoinHandle<()>>>,
+}
+
+impl KotlinBridge {
+    pub(crate) fn new(
+        root: PathBuf,
+        cache: PathBuf,
+        data: &Path,
+        settings: Arc<SettingsStore>,
+        lsp: Arc<LspManager>,
+        sink: SharedSink,
+        trusted: Arc<AtomicBool>,
+    ) -> Arc<Self> {
+        let options = std::fs::read(cache.join("kotlin-bridge-options.json"))
+            .ok()
+            .and_then(|bytes| serde_json::from_slice(&bytes).ok())
+            .unwrap_or_default();
+        Arc::new(Self {
+            root,
+            cache,
+            bundle: ide_sdk::java::kotlin_bridge_bundle(data),
+            settings,
+            lsp,
+            sink,
+            trusted,
+            lifetime: CancellationToken::new(),
+            revision: Mutex::new(Revision::default()),
+            changed: Notify::new(),
+            options: Mutex::new(options),
+            worker: Mutex::new(None),
+        })
+    }
+
+    pub(crate) fn start(self: &Arc<Self>, runtime: &tokio::runtime::Handle) {
+        let bridge = self.clone();
+        *self.worker.lock() = Some(runtime.spawn(async move { bridge.run().await }));
+        self.schedule();
+    }
+
+    pub(crate) fn configure_maven(&self, offline: bool, profiles: Vec<String>) {
+        let options = MavenOptions { offline, profiles };
+        if let Ok(bytes) = serde_json::to_vec(&options) {
+            let _ = std::fs::create_dir_all(&self.cache);
+            let _ = std::fs::write(self.cache.join("kotlin-bridge-options.json"), bytes);
+        }
+        *self.options.lock() = options;
+        self.schedule();
+    }
+
+    pub(crate) async fn shutdown(&self) {
+        self.stop();
+        let worker = self.worker.lock().take();
+        if let Some(worker) = worker {
+            let _ = worker.await;
+        }
+    }
+
+    pub(crate) fn schedule(&self) {
+        if self.lifetime.is_cancelled() {
+            return;
+        }
+        self.revision.lock().change();
+        self.changed.notify_one();
+    }
+
+    pub(crate) fn files_changed<'a>(&self, mut paths: impl Iterator<Item = &'a PathBuf>) {
+        let settings = self.settings.effective();
+        if paths.any(|path| relevant_change(&self.root, path, &settings)) {
+            self.schedule();
+        }
+    }
+
+    pub(crate) fn stop(&self) {
+        self.lifetime.cancel();
+        self.revision.lock().cancel.cancel();
+    }
+
+    async fn replace(&self, projects: &[ProjectLibraries], cancel: &CancellationToken) -> ide_core::IdeResult<()> {
+        let snapshot = serde_json::to_value(projects).map_err(|e| ide_core::IdeError::internal(e.to_string()))?;
+        let response = self.lsp.jdtls_command_cancellable(&self.root, COMMAND, vec![snapshot], cancel).await?;
+        if response.as_u64().is_none() {
+            return Err(ide_core::IdeError::unavailable(
+                "Kotlin bridge command did not acknowledge its library snapshot",
+            ));
+        }
+        Ok(())
+    }
+
+    async fn run(self: Arc<Self>) {
+        let mut diagnostics = BTreeSet::new();
+        let mut last_failure = String::new();
+        let mut initialized = false;
+        // Also retain directories from unacknowledged replacements: JDT may have applied them.
+        let mut published = Vec::new();
+        loop {
+            tokio::select! {
+                _ = self.lifetime.cancelled() => return,
+                _ = self.changed.notified() => {},
+            }
+            let (generation, cancel) = {
+                let state = self.revision.lock();
+                (state.generation, state.cancel.clone())
+            };
+            if !self.trusted.load(Ordering::Acquire) {
+                continue;
+            }
+            if !debounce(&cancel, &self.lifetime).await {
+                continue;
+            }
+            let root = self.root.clone();
+            let cache = self.cache.clone();
+            let settings = self.settings.effective();
+            let has_sources = tokio::task::spawn_blocking(move || {
+                let model = crate::ops::build::load(&root, &cache, &settings);
+                let enabled =
+                    model.maven.as_ref().is_some_and(|m| !m.projects.is_empty()) && kotlin_bridge::has_kotlin(&root);
+                (model, enabled)
+            })
+            .await;
+            let Ok((mut model, enabled)) = has_sources else { continue };
+            if !self.revision.lock().current(generation) {
+                continue;
+            }
+            if !enabled {
+                if self.cache.join("kotlin-bridge").exists()
+                    && let Err(error) = self.replace(&[], &cancel).await
+                {
+                    if !cancel.is_cancelled() {
+                        tracing::warn!("Kotlin library withdrawal: {error}");
+                    }
+                    continue;
+                }
+                for old in published.drain(..) {
+                    remove_directory(old).await;
+                }
+                self.clear_diagnostics(&mut diagnostics);
+                last_failure.clear();
+                continue;
+            }
+            if let Some(maven) = &mut model.maven {
+                let options = self.options.lock();
+                for module in &mut maven.projects {
+                    if options.offline {
+                        module.options.push("-o".into());
+                    }
+                    if !options.profiles.is_empty() {
+                        module.options.push(format!("-P{}", options.profiles.join(",")));
+                    }
+                }
+            }
+            let Some(bundle) = self.bundle.clone() else {
+                self.failure("Kotlin bridge bundle is unavailable".into(), &mut diagnostics, &mut last_failure);
+                continue;
+            };
+            // Clear entries persisted by an earlier incarnation only before our first build.
+            if !initialized {
+                if let Err(error) = self.replace(&[], &cancel).await {
+                    if !cancel.is_cancelled() {
+                        self.failure(error.message, &mut diagnostics, &mut last_failure);
+                    }
+                    continue;
+                }
+                initialized = true;
+            }
+            let directory = self.cache.join(format!("kotlin-bridge/{}", uuid::Uuid::new_v4()));
+            let staging = directory.clone();
+            let root = self.root.clone();
+            let token = cancel.clone();
+            let result =
+                tokio::task::spawn_blocking(move || kotlin_bridge::build(&root, &model, &bundle, &staging, &token))
+                    .await;
+            if !self.revision.lock().current(generation) || self.lifetime.is_cancelled() {
+                remove_directory(directory).await;
+                continue;
+            }
+            match result {
+                Ok(Ok(Outcome { success: true, projects, .. })) => {
+                    match self.replace(&projects, &cancel).await {
+                        Ok(()) => {
+                            for old in published.drain(..) {
+                                remove_directory(old).await;
+                            }
+                            published.push(directory);
+                            self.clear_diagnostics(&mut diagnostics);
+                            last_failure.clear();
+                        }
+                        Err(error) => {
+                            // Keep both snapshots until an acknowledged replacement.
+                            published.push(directory);
+                            if !cancel.is_cancelled() {
+                                self.failure(error.message, &mut diagnostics, &mut last_failure);
+                            }
+                        }
+                    }
+                }
+                other => {
+                    let text = match other {
+                        Ok(Ok(outcome)) => outcome
+                            .messages
+                            .iter()
+                            .filter(|m| m.severity == Severity::Error)
+                            .map(|m| m.text.as_str())
+                            .collect::<Vec<_>>()
+                            .join("\n"),
+                        Ok(Err(error)) => error.message,
+                        Err(error) => error.to_string(),
+                    };
+                    self.failure(text, &mut diagnostics, &mut last_failure);
+                    remove_directory(directory).await;
+                }
+            }
+        }
+    }
+
+    fn clear_diagnostics(&self, paths: &mut BTreeSet<PathBuf>) {
+        for path in std::mem::take(paths) {
+            self.sink.emit(IdeEvent::Diagnostics { path: path.into(), source: SOURCE.into(), items: Vec::new() });
+        }
+    }
+
+    fn failure(&self, text: String, paths: &mut BTreeSet<PathBuf>, previous: &mut String) {
+        let text = if text.is_empty() { "Kotlin compilation failed".to_owned() } else { text };
+        let text = format!("{text}\nJava temporarily uses the last successfully compiled Kotlin API.");
+        self.clear_diagnostics(paths);
+        let path = self.root.join("pom.xml");
+        paths.insert(path.clone());
+        self.sink.emit(IdeEvent::Diagnostics {
+            path: path.into(),
+            source: SOURCE.into(),
+            items: vec![Diagnostic {
+                range: Range { start: Pos { line: 0, col: 0 }, end: Pos { line: 0, col: 0 } },
+                severity: Severity::Error,
+                message: text.clone(),
+                source: Some(SOURCE.into()),
+                server: Some(SOURCE.into()),
+                code: None,
+                unnecessary: false,
+                deprecated: false,
+            }],
+        });
+        if previous != &text {
+            self.sink.emit(IdeEvent::Notify {
+                level: NotifyLevel::Error,
+                title: "Kotlin editor compilation failed".into(),
+                body: Some(text.clone()),
+            });
+            *previous = text;
+        }
+    }
+}
+
+fn relevant_change(root: &Path, path: &Path, settings: &ide_core::settings::Settings) -> bool {
+    let input = path.extension().is_some_and(|e| e == "kt")
+        || path.file_name().is_some_and(|n| n == "pom.xml" || n == "mvnw" || n == "mvnw.cmd")
+        || path.components().any(|c| c.as_os_str() == ".mvn");
+    let Ok(relative) = path.strip_prefix(root) else {
+        // Content roots outside the project only contribute Kotlin sources.
+        return path.extension().is_some_and(|e| e == "kt");
+    };
+    // Build outputs and generated sources (e.g. KSP's `.kt` under target/) never trigger,
+    // so a build cannot schedule itself.
+    if relative.components().any(|c| {
+        matches!(
+            c.as_os_str().to_str(),
+            Some("target" | "build" | "out" | "bin" | ".git" | "node_modules" | ".openidea")
+        )
+    }) || ide_vfs::ExcludeMatcher::new(&settings.exclude_globs()).is_excluded(relative)
+    {
+        return false;
+    }
+    if input {
+        return true;
+    }
+    if path.extension().is_some() {
+        return false;
+    }
+    // Works for deleted directories too; the module POM remains on disk.
+    path.ancestors().take_while(|ancestor| ancestor.starts_with(root)).any(|ancestor| {
+        ancestor.file_name().is_some_and(|name| name == "src")
+            && ancestor.parent().is_some_and(|module| module.join("pom.xml").is_file())
+    })
+}
+
+async fn debounce(cancel: &CancellationToken, lifetime: &CancellationToken) -> bool {
+    tokio::select! {
+        _ = lifetime.cancelled() => false,
+        _ = cancel.cancelled() => false,
+        _ = tokio::time::sleep(DELAY) => true,
+    }
+}
+
+async fn remove_directory(path: PathBuf) {
+    let _ = tokio::task::spawn_blocking(move || std::fs::remove_dir_all(path)).await;
+}
+
+impl DocumentObserver for KotlinBridge {
+    fn saved(&self, _doc: ide_core::DocId, path: &Path, _text: &str) {
+        self.files_changed(std::iter::once(&path.to_path_buf()));
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn target_package_directory_does_not_trigger() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::write(dir.path().join("pom.xml"), "").unwrap();
+        assert!(!relevant_change(dir.path(), &dir.path().join("target/classes/probe"), &Default::default()));
+        let generated = dir.path().join("target/generated-sources/ksp/main/kotlin/Gen.kt");
+        assert!(!relevant_change(dir.path(), &generated, &Default::default()));
+        assert!(relevant_change(dir.path(), &dir.path().join("src/main/kotlin/A.kt"), &Default::default()));
+    }
+
+    #[test]
+    fn deleted_source_package_triggers_unless_excluded() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::create_dir_all(dir.path().join("module")).unwrap();
+        std::fs::write(dir.path().join("module/pom.xml"), "").unwrap();
+        let path = dir.path().join("module/src/main/kotlin/pkg");
+        let mut settings = ide_core::settings::Settings::default();
+        assert!(relevant_change(dir.path(), &path, &settings));
+        settings.project_structure.excluded.push("module/src/main/kotlin".into());
+        assert!(!relevant_change(dir.path(), &path, &settings));
+        assert!(!relevant_change(dir.path(), &dir.path().join("module/src/build/pkg"), &Default::default()));
+    }
+
+    #[test]
+    fn extensionless_root_file_does_not_trigger() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::write(dir.path().join("pom.xml"), "").unwrap();
+        assert!(!relevant_change(dir.path(), &dir.path().join("LICENSE"), &Default::default()));
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn burst_saves_cancel_the_pending_debounce() {
+        let mut state = Revision::default();
+        state.change();
+        let token = state.cancel.clone();
+        let lifetime = CancellationToken::new();
+        let pending_lifetime = lifetime.clone();
+        let waiting = tokio::spawn(async move { debounce(&token, &pending_lifetime).await });
+        tokio::task::yield_now().await;
+        tokio::time::advance(DELAY - Duration::from_millis(1)).await;
+        assert!(!waiting.is_finished());
+        for _ in 0..20 {
+            state.change();
+        }
+        assert!(!waiting.await.unwrap());
+        let current = state.generation;
+        assert!(debounce(&state.cancel, &lifetime).await);
+        assert!(state.current(current));
+        lifetime.cancel();
+        assert!(!debounce(&state.cancel, &lifetime).await);
+    }
+
+    #[test]
+    fn superseded_and_cancelled_builds_cannot_publish() {
+        let mut state = Revision::default();
+        state.change();
+        let first = state.generation;
+        let token = state.cancel.clone();
+        state.change();
+        assert!(token.is_cancelled());
+        assert!(!state.current(first));
+        assert!(state.current(state.generation));
+        state.cancel.cancel();
+        assert!(!state.current(state.generation));
+    }
+}
@@ -4,7 +4,9 @@
 //! runs one on a remote machine and serves it over JSON-RPC ([`rpc`]).

 pub mod environment;
+mod formatter;
 mod java_runtime;
+mod kotlin_bridge;
 pub mod notebook;
 pub mod ops;
 mod project;
@@ -148,9 +150,15 @@ impl Host {
            if !project.light {
                self.environment.project_closed();
            }
+            if let Some(bridge) = &project.kotlin_bridge {
+                bridge.stop();
+            }
            project.agents.shutdown();
            project.notebooks.stop_admission();
-            self.shutdown_notebooks_blocking(vec![project.notebooks.clone()]);
+            self.shutdown_project_workers_blocking(
+                vec![project.notebooks.clone()],
+                project.kotlin_bridge.iter().cloned().collect(),
+            );
            let lsp = project.lsp.clone();
            self.runtime.spawn(async move { lsp.shutdown_all().await });
        }
@@ -158,7 +166,14 @@ impl Host {

    /// Synchronous project/window destruction must finish owned kernel cleanup,
    /// not enqueue work which can be lost as the desktop runtime exits.
-    fn shutdown_notebooks_blocking(&self, notebooks: Vec<Arc<notebook::NotebookService>>) {
+    fn shutdown_project_workers_blocking(
+        &self,
+        notebooks: Vec<Arc<notebook::NotebookService>>,
+        bridges: Vec<Arc<kotlin_bridge::KotlinBridge>>,
+    ) {
+        for bridge in &bridges {
+            bridge.stop();
+        }
        for service in &notebooks {
            service.stop_admission();
        }
@@ -166,6 +181,9 @@ impl Host {
        let wait = move || {
            let worker = std::thread::spawn(move || {
                runtime.block_on(async move {
+                    for bridge in bridges {
+                        bridge.shutdown().await;
+                    }
                    for service in notebooks {
                        service.shutdown().await;
                    }
@@ -186,7 +204,11 @@ impl Host {

    /// Called before the desktop runtime exits, including update/restart exits.
    pub fn shutdown_notebooks_on_exit(&self) {
-        self.shutdown_notebooks_blocking(self.projects().iter().map(|project| project.notebooks.clone()).collect());
+        let projects = self.projects();
+        self.shutdown_project_workers_blocking(
+            projects.iter().map(|project| project.notebooks.clone()).collect(),
+            projects.iter().filter_map(|project| project.kotlin_bridge.clone()).collect(),
+        );
    }

    /// Stops what this host started: notebook kernels, language servers, agents, runs and terminals.
@@ -197,12 +219,18 @@ impl Host {
        self.terminals.kill_all();
        let projects: Vec<_> = self.projects.write().drain().map(|(_, p)| p).collect();
        for project in &projects {
+            if let Some(bridge) = &project.kotlin_bridge {
+                bridge.stop();
+            }
            project.notebooks.stop_admission();
            project.agents.shutdown();
        }
        // Kernel cleanup owns its interrupt/termination/reaping deadlines. An
        // outer LSP timeout must never abort it before owned children are reaped.
        for project in &projects {
+            if let Some(bridge) = &project.kotlin_bridge {
+                bridge.shutdown().await;
+            }
            project.notebooks.shutdown().await;
        }
        let stop_language_servers = async {
@@ -97,6 +97,7 @@ pub async fn build_sync(
    host.require_trust(window)?;
    let project = host.project(window)?;
    let (root, cache, settings) = (project.root.clone(), project.build_cache_dir(), project.settings.effective());
+    let bridge_profiles = profiles.clone();
    let token = host.begin_project_request(window, request);
    let result = tokio::task::spawn_blocking(move || {
        let current = load(&root, &cache, &settings);
@@ -137,6 +138,9 @@ pub async fn build_sync(
        // jdtls re-imports on pom changes but misses artifacts added to ~/.m2
        // meanwhile ("missing artifact" stays until Invalidate Caches); asking it
        // to update the project configurations re-resolves them (#436).
+        if let Some(bridge) = &project.kotlin_bridge {
+            bridge.configure_maven(offline, bridge_profiles);
+        }
        let lsp = project.lsp.clone();
        let uris = maven.projects.iter().map(|p| ide_lsp::path_to_uri_string(&project.root.join(&p.pom))).collect();
        tokio::spawn(async move {
@@ -96,7 +96,13 @@ fn match_java_debug_encoding(mut config: LaunchConfig, windows: bool) -> LaunchC
    };
    let vm_args = extra.get("vmArgs").and_then(|v| v.as_str()).unwrap_or_default();
    let encoding = extra.get("encoding").and_then(|v| v.as_str());
-    if let Some(vm_args) = ide_core::output_encoding::java_debug_vm_args(vm_args, encoding, windows) {
+    if let Some(vm_args) = ide_core::output_encoding::java_debug_vm_args(
+        vm_args,
+        &config.env,
+        |key| std::env::var(key).ok(),
+        encoding,
+        windows,
+    ) {
        extra.insert("vmArgs".into(), vm_args.into());
        config.extra_json = Some(serde_json::Value::Object(extra).to_string());
    }
@@ -452,7 +458,7 @@ mod tests {
            program: None,
            args: vec![],
            cwd: None,
-            env: Default::default(),
+            env: [("JDK_JAVA_OPTIONS".into(), "".into()), ("JAVA_TOOL_OPTIONS".into(), "".into())].into(),
            extra_json: Some(extra.to_string()),
        }
    }
@@ -468,7 +474,7 @@ mod tests {
        let fixed = match_java_debug_encoding(launch("java-debug", "launch", extra.clone()), true);
        assert_eq!(
            vm_args(&fixed),
-            "-Xmx1g -Dstdout.encoding=UTF-8 -Dstderr.encoding=UTF-8 -Dsun.stdout.encoding=UTF-8 -Dsun.stderr.encoding=UTF-8"
+            "-Xmx1g -Dstdout.encoding=UTF-8 -Dstderr.encoding=UTF-8 -Dsun.stdout.encoding=UTF-8 -Dsun.stderr.encoding=UTF-8 -Dfile.encoding=UTF-8"
        );
        assert_eq!(
            serde_json::from_str::<serde_json::Value>(fixed.extra_json.as_deref().unwrap()).unwrap()["mainClass"],
@@ -481,4 +487,13 @@ mod tests {
            assert_eq!(vm_args(&match_java_debug_encoding(launch(adapter, request, extra.clone()), windows)), "-Xmx1g");
        }
    }
+
+    #[test]
+    fn java_debug_launches_respect_environment_encoding() {
+        for key in ["JDK_JAVA_OPTIONS", "JAVA_TOOL_OPTIONS"] {
+            let mut config = launch("java-debug", "launch", serde_json::json!({"vmArgs": "-Dstdout.encoding=GBK"}));
+            config.env.insert(key.into(), "-Dfile.encoding=GBK".into());
+            assert_eq!(vm_args(&match_java_debug_encoding(config, true)), "-Dstdout.encoding=GBK");
+        }
+    }
 }
@@ -1,8 +1,73 @@
+use super::Channel;
 use crate::Host;
-use ide_core::IdeResult;
+use ide_core::{IdeResult, RequestId};
 use ide_vfs::FileEntry;
 use std::path::PathBuf;

+pub async fn entry_kind(host: &Host, path: PathBuf) -> IdeResult<ide_vfs::EntryKind> {
+    host.blocking(move || {
+        let meta = std::fs::metadata(path)?;
+        Ok(if meta.is_dir() { ide_vfs::EntryKind::Dir } else { ide_vfs::EntryKind::File })
+    })
+    .await
+}
+
+pub async fn compare_directories(
+    host: &Host,
+    window: &str,
+    left: PathBuf,
+    right: PathBuf,
+    request: RequestId,
+    on_progress: Channel<ide_vfs::DirectoryCompareProgress>,
+) -> IdeResult<Vec<ide_vfs::DirectoryCompareEntry>> {
+    let project = host.project(window)?;
+    let cancel = host.begin_request(request);
+    let result = host
+        .blocking(move || {
+            let last = std::cell::Cell::new(std::time::Instant::now() - std::time::Duration::from_secs(1));
+            ide_vfs::compare_directories(&left, &right, Some(&project.root), &project.exclude_globs(), &cancel, |p| {
+                // Bound IPC traffic even when hashing multi-gigabyte files.
+                if last.get().elapsed() >= std::time::Duration::from_millis(80) || p.total == Some(p.compared) {
+                    let _ = on_progress.send(p);
+                    last.set(std::time::Instant::now());
+                }
+            })
+        })
+        .await;
+    host.end_request(request);
+    result
+}
+
+pub async fn copy_merge(
+    host: &Host,
+    window: &str,
+    source_root: PathBuf,
+    destination_root: PathBuf,
+    path: PathBuf,
+    overwrite: bool,
+) -> IdeResult<()> {
+    if path.as_os_str().is_empty() || path.components().any(|c| !matches!(c, std::path::Component::Normal(_))) {
+        return Err(ide_core::IdeError::invalid("expected a relative comparison entry path"));
+    }
+    let project = host.project(window)?;
+    host.blocking(move || {
+        let from = source_root.join(&path);
+        let to = destination_root.join(&path);
+        if overwrite {
+            project.history.record_deletion(&to, DELETE_SNAPSHOT_LIMIT);
+        }
+        ide_vfs::copy_merge(
+            &from,
+            &to,
+            overwrite,
+            Some(&project.root),
+            &project.exclude_globs(),
+            (&source_root, &destination_root),
+        )
+    })
+    .await
+}
+
 /// Files of a deleted folder snapshotted in Local History.
 const DELETE_SNAPSHOT_LIMIT: usize = 2000;

@@ -1,11 +1,13 @@
 //! Java launch support: classpath / JDK resolution and the java-debug server (jdtls).
+pub(crate) mod cache;
+
 use crate::Host;
 use crate::rpc::Dispatcher;

 use super::build::load;
 use ide_build::compile;
 use ide_core::{CancellationToken, IdeError, IdeResult, RequestId};
-use ide_lsp::jdtls::JavaLaunchInfo;
+use ide_lsp::jdtls::{JavaBuildStatus, JavaLaunchInfo};
 use std::path::PathBuf;

 /// Cancellable with `cancel_request(request)`.
@@ -39,20 +41,46 @@ async fn resolve_launch(
    let project = host.project(window)?;
    let module = project.root.join(module);
    let settings = project.settings.effective();
-    // Let jdtls finish its build before the external compiler writes Kotlin/Scala classes.
-    let mut info = project.lsp.java_launch(&module, test, build, cancel).await?;
+    let (model, external, delegated) = {
+        let project = project.clone();
+        let settings = settings.clone();
+        let module = module.clone();
+        tokio::task::spawn_blocking(move || {
+            project.java_launch_snapshots.lock().initialize();
+            let model = load(&project.root, &project.build_cache_dir(), &settings);
+            let non_java = build && compile::launch_has_non_java_sources(&project.root, &model, &module, test);
+            let delegated = build
+                && model.maven.as_ref().is_some_and(|m| m.projects.iter().any(|p| project.root.join(&p.dir) == module))
+                && (non_java || cache::has_record(&project.root, &project.build_cache_dir(), &module));
+            let external = non_java || delegated;
+            (model, external, delegated)
+        })
+        .await
+        .map_err(|e| IdeError::internal(e.to_string()))?
+    };
+    let external_build = if delegated { Some(project.lsp.java_external_build(&module, cancel).await?) } else { None };
+    let mut info = project.lsp.java_launch(&module, test, build && !delegated, cancel).await?;
    let lsp_ms = started.elapsed().as_millis();
    let data_dir = host.data_dir.clone();
    let cancel = cancel.clone();
    tokio::task::spawn_blocking(move || {
-        let built = if build && compile::has_non_java_sources(&module) {
-            compile::build_for_launch(
+        let _external_build = external_build;
+        let built = if delegated {
+            let outputs = project.java_launch_snapshots.lock().build(
                &project.root,
-                &load(&project.root, &project.build_cache_dir(), &settings),
+                &model,
                &module,
                test,
+                ide_sdk::apply::maven_local_repository(&project.root, &settings),
                &cancel,
-            )?
+            )?;
+            let copies = use_snapshot(&mut info, &outputs.originals, &outputs.snapshot);
+            info.build = Some(JavaBuildStatus::Succeeded);
+            info.errors.clear();
+            info.error_count = 0;
+            copies
+        } else if external {
+            compile::build_for_launch(&project.root, &model, &module, test, &cancel)?
        } else {
            Vec::new()
        };
@@ -103,6 +131,26 @@ async fn resolve_launch(
    .map_err(|e| IdeError::internal(e.to_string()))?
 }

+fn use_snapshot(info: &mut JavaLaunchInfo, built: &[PathBuf], snapshot: &std::path::Path) -> Vec<PathBuf> {
+    let mut copies = Vec::new();
+    for (index, source) in built.iter().enumerate() {
+        let dest = snapshot.join(index.to_string());
+        let original = source.to_string_lossy();
+        info.class_paths.retain(|p| p != original.as_ref());
+        let mut modular = false;
+        for path in &mut info.module_paths {
+            if path == original.as_ref() {
+                *path = dest.to_string_lossy().into_owned();
+                modular = true;
+            }
+        }
+        if !modular {
+            copies.push(dest);
+        }
+    }
+    copies
+}
+
 /// Port of java-debug's DAP server inside the jdtls serving `module` (started on demand).
 pub async fn java_debug_server(host: &Host, window: &str, module: PathBuf) -> IdeResult<u16> {
    host.require_trust(window)?;
@@ -132,3 +180,40 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("java_debug_server", |c| async move { java_debug_server(&c.host, &c.window, c.arg("module")?).await });
    d.add("java_build_workspace", |c| async move { java_build_workspace(&c.host, &c.window, c.arg("module")?).await });
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn launch_snapshots_survive_jdt_overwrites_and_replace_module_outputs() {
+        let root = tempfile::tempdir().unwrap();
+        let app = root.path().join("app/target/classes");
+        let lib = root.path().join("lib/target/classes");
+        for dir in [&app, &lib] {
+            std::fs::create_dir_all(dir).unwrap();
+            std::fs::write(dir.join("Channel.class"), "Maven bytecode").unwrap();
+        }
+        let mut info = JavaLaunchInfo {
+            class_paths: vec![app.to_string_lossy().into_owned(), "stdlib.jar".into()],
+            module_paths: vec![lib.to_string_lossy().into_owned()],
+            ..Default::default()
+        };
+        let snapshot = tempfile::tempdir().unwrap();
+        for (i, source) in [&app, &lib].iter().enumerate() {
+            ide_vfs::copy(source, &snapshot.path().join(i.to_string())).unwrap();
+        }
+        let paths = use_snapshot(&mut info, &[app.clone(), lib.clone()], snapshot.path());
+        assert_eq!(paths, [snapshot.path().join("0")]);
+        assert_eq!(info.class_paths, ["stdlib.jar"]);
+        assert_eq!(info.module_paths, [snapshot.path().join("1").to_string_lossy().into_owned()]);
+        std::fs::write(app.join("Channel.class"), "JDT error stub").unwrap();
+        std::fs::remove_dir_all(lib).unwrap();
+        for index in ["0", "1"] {
+            assert_eq!(
+                std::fs::read_to_string(snapshot.path().join(index).join("Channel.class")).unwrap(),
+                "Maven bytecode"
+            );
+        }
+    }
+}
@@ -0,0 +1,371 @@
+//! Immutable Maven outputs retained in the project cache, including across close/reopen.
+use ide_build::compile::{self, LaunchFingerprint};
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use serde::{Deserialize, Serialize};
+use std::collections::HashSet;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+#[derive(Debug, Serialize, Deserialize)]
+pub(super) struct Outputs {
+    fingerprint: Option<LaunchFingerprint>,
+    pub snapshot: PathBuf,
+    pub originals: Vec<PathBuf>,
+}
+
+impl Outputs {
+    fn reusable(&self, fingerprint: &Option<LaunchFingerprint>, snapshots: &Path) -> bool {
+        fingerprint.is_some()
+            && self.fingerprint == *fingerprint
+            && self.snapshot.parent() == Some(snapshots)
+            && !self.originals.is_empty()
+            && (0..self.originals.len()).all(|i| self.snapshot.join(i.to_string()).is_dir())
+    }
+}
+
+fn record_path(root: &Path, cache: &Path, module: &Path, test: bool) -> Option<PathBuf> {
+    Some(cache.join("java-launch/records").join(module.strip_prefix(root).ok()?).join(if test {
+        "test.json"
+    } else {
+        "main.json"
+    }))
+}
+
+pub(super) fn has_record(root: &Path, cache: &Path, module: &Path) -> bool {
+    [false, true].into_iter().any(|test| record_path(root, cache, module, test).is_some_and(|record| record.is_file()))
+}
+
+/// Owned by Project: running JVMs may still load superseded outputs until it drops.
+pub(crate) struct Session {
+    cache: PathBuf,
+    initialized: bool,
+    unreferenced: Vec<PathBuf>,
+}
+
+impl Session {
+    pub(crate) fn new(cache: PathBuf) -> Self {
+        Self { cache, initialized: false, unreferenced: Vec::new() }
+    }
+
+    pub(super) fn initialize(&mut self) {
+        if !self.initialized {
+            self.initialized = true;
+            if let Err(error) = sweep(&self.cache) {
+                tracing::warn!(%error, "Cannot clean previous Java launch snapshots");
+            }
+        }
+    }
+
+    pub(super) fn build(
+        &mut self,
+        root: &Path,
+        model: &ide_build::BuildModel,
+        module: &Path,
+        test: bool,
+        local_repo: Option<PathBuf>,
+        cancel: &CancellationToken,
+    ) -> IdeResult<Outputs> {
+        self.initialize();
+        let cache = &self.cache;
+        let record =
+            record_path(root, cache, module, test).ok_or_else(|| IdeError::internal("launch outside project"))?;
+        let snapshots = cache.join("java-launch/snapshots");
+        let fingerprint = || match compile::launch_fingerprint(root, model, module, test, local_repo.clone(), cancel) {
+            Ok(value) => Ok(value),
+            Err(e) if cancel.is_cancelled() => Err(e),
+            Err(e) => {
+                tracing::debug!(error = %e, "Cannot fingerprint Maven launch; rebuilding");
+                Ok(None)
+            }
+        };
+        let before = fingerprint()?;
+        let previous = fs::read(&record).ok().and_then(|bytes| serde_json::from_slice::<Outputs>(&bytes).ok());
+        if let Some(outputs) = previous.as_ref()
+            && outputs.reusable(&before, &snapshots)
+        {
+            tracing::info!(module = %module.display(), test, "Reusing Maven launch snapshot");
+            return Ok(previous.unwrap());
+        }
+        // Retain a non-reusable record even on failure, so removing the final mixed
+        // source still delegates to Maven to clean its old classes on the next launch.
+        fs::create_dir_all(record.parent().unwrap())?;
+        fs::write(&record, b"null")?;
+        if let Some(previous) = previous {
+            self.unreferenced.push(previous.snapshot);
+        }
+        let originals = compile::build_for_launch(root, model, module, test, cancel)?;
+        fs::create_dir_all(&snapshots)?;
+        let snapshot = tempfile::Builder::new().prefix("launch-").tempdir_in(&snapshots)?.keep();
+        // Retain every new snapshot even if copying or publishing its record fails.
+        self.unreferenced.push(snapshot.clone());
+        for (i, source) in originals.iter().enumerate() {
+            if cancel.is_cancelled() {
+                return Err(IdeError::cancelled());
+            }
+            ide_vfs::copy(source, &snapshot.join(i.to_string()))?;
+        }
+        let after = fingerprint()?;
+        if cancel.is_cancelled() {
+            return Err(IdeError::cancelled());
+        }
+        let mut outputs = Outputs { fingerprint: None, snapshot, originals };
+        if before.is_some() && before == after {
+            outputs.fingerprint = before;
+            fs::create_dir_all(record.parent().unwrap())?;
+            let mut file = tempfile::NamedTempFile::new_in(record.parent().unwrap())?;
+            serde_json::to_writer(file.as_file_mut(), &outputs).map_err(|e| IdeError::internal(e.to_string()))?;
+            file.persist(&record).map_err(|e| IdeError::from(e.error))?;
+            self.unreferenced.retain(|path| path != &outputs.snapshot);
+        }
+        Ok(outputs)
+    }
+}
+
+impl Drop for Session {
+    fn drop(&mut self) {
+        // Recheck all records: another module or launch mode may reference a path.
+        if let Ok(referenced) = referenced_snapshots(&self.cache) {
+            let snapshots = self.cache.join("java-launch/snapshots");
+            for path in &self.unreferenced {
+                remove_unreferenced(path, &snapshots, &referenced);
+            }
+        }
+    }
+}
+
+fn referenced_snapshots(cache: &Path) -> std::io::Result<HashSet<PathBuf>> {
+    let mut referenced = HashSet::new();
+    let records = cache.join("java-launch/records");
+    if !records.try_exists()? {
+        return Ok(referenced);
+    }
+    let mut pending = vec![records];
+    while let Some(dir) = pending.pop() {
+        for entry in fs::read_dir(dir)? {
+            let entry = entry?;
+            let kind = entry.file_type()?;
+            if kind.is_dir() {
+                pending.push(entry.path());
+            } else if kind.is_file() && entry.path().extension().is_some_and(|ext| ext == "json") {
+                let outputs: Option<Outputs> = serde_json::from_slice(&fs::read(entry.path())?)?;
+                if let Some(outputs) = outputs
+                    && let Ok(path) = fs::canonicalize(outputs.snapshot)
+                {
+                    referenced.insert(path);
+                }
+            }
+        }
+    }
+    Ok(referenced)
+}
+
+fn remove_unreferenced(path: &Path, snapshots: &Path, referenced: &HashSet<PathBuf>) {
+    // Only real launch-* directories directly inside snapshots, never symlinks.
+    if path.parent() != Some(snapshots)
+        || !path.file_name().is_some_and(|name| name.to_string_lossy().starts_with("launch-"))
+        || !fs::symlink_metadata(path).is_ok_and(|meta| meta.file_type().is_dir())
+    {
+        return;
+    }
+    if let (Ok(path), Ok(snapshots)) = (fs::canonicalize(path), fs::canonicalize(snapshots))
+        && path.parent() == Some(snapshots.as_path())
+        && !referenced.contains(&path)
+        && let Err(error) = fs::remove_dir_all(&path)
+    {
+        tracing::warn!(%error, path = %path.display(), "Cannot remove Java launch snapshot");
+    }
+}
+
+fn sweep(cache: &Path) -> std::io::Result<()> {
+    let referenced = referenced_snapshots(cache)?;
+    let snapshots = cache.join("java-launch/snapshots");
+    if snapshots.try_exists()? {
+        for entry in fs::read_dir(&snapshots)? {
+            remove_unreferenced(&entry?.path(), &snapshots, &referenced);
+        }
+    }
+    Ok(())
+}
+
+#[cfg(all(test, unix))]
+mod tests {
+    use super::*;
+    use std::os::unix::fs::PermissionsExt;
+
+    fn fixture(root: &Path) -> ide_build::BuildModel {
+        fs::write(
+            root.join("pom.xml"),
+            r#"<project><groupId>demo</groupId><artifactId>app</artifactId><version>1</version></project>"#,
+        )
+        .unwrap();
+        let script = root.join("mvnw");
+        fs::write(&script, "#!/bin/sh\necho build >> calls\nif [ -f src/main/kotlin/broken ]; then exit 1; fi\nmkdir -p target/classes\ncp src/main/kotlin/Main.kt target/classes/Main.class\n").unwrap();
+        fs::set_permissions(&script, fs::Permissions::from_mode(0o755)).unwrap();
+        fs::create_dir_all(root.join("src/main/kotlin")).unwrap();
+        fs::write(root.join("src/main/kotlin/Main.kt"), "first").unwrap();
+        ide_build::load(root, &root.join("cache"), None)
+    }
+
+    #[test]
+    fn successful_snapshots_reuse_across_close_and_rebuild_for_changes_missing_outputs_or_failure() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cache = root.join("cache");
+        let cancel = CancellationToken::new();
+        let mut session = Session::new(cache.clone());
+        let mut build = || session.build(root, &model, root, false, None, &cancel);
+        let first = build().unwrap();
+        let snapshot = first.snapshot.clone();
+        drop(first);
+        // Dropping an Outputs value leaves the persisted snapshot reusable.
+        let second = build().unwrap();
+        assert_eq!(snapshot, second.snapshot);
+        assert_eq!(fs::read_to_string(root.join("calls")).unwrap().lines().count(), 1);
+        fs::write(root.join("target/classes/Main.class"), "JDT stub").unwrap();
+        assert_eq!(snapshot, build().unwrap().snapshot);
+        assert_eq!(fs::read_to_string(snapshot.join("0/Main.class")).unwrap(), "first");
+        fs::write(root.join("src/main/kotlin/Main.kt"), "updated").unwrap();
+        let updated = build().unwrap();
+        assert_ne!(snapshot, updated.snapshot);
+        assert_eq!(fs::read_to_string(updated.snapshot.join("0/Main.class")).unwrap(), "updated");
+        assert!(snapshot.join("0/Main.class").is_file(), "previous JVMs may still load it");
+        fs::remove_dir_all(updated.snapshot.join("0")).unwrap();
+        let rebuilt = build().unwrap();
+        assert_ne!(rebuilt.snapshot, updated.snapshot);
+        fs::write(root.join("src/main/kotlin/broken"), "broken").unwrap();
+        assert!(build().is_err());
+        assert_eq!(fs::read(cache.join("java-launch/records/main.json")).unwrap(), b"null");
+        fs::remove_file(root.join("src/main/kotlin/broken")).unwrap();
+        assert_ne!(rebuilt.snapshot, build().unwrap().snapshot, "a failed build invalidates success");
+        cancel.cancel();
+        assert!(build().is_err());
+        assert_eq!(fs::read_to_string(root.join("calls")).unwrap().lines().count(), 5);
+    }
+    #[test]
+    fn session_drop_removes_superseded_snapshots_and_preserves_records_across_reopen() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cache = root.join("cache");
+        let cancel = CancellationToken::new();
+        let mut session = Session::new(cache.clone());
+        let first = session.build(root, &model, root, false, None, &cancel).unwrap();
+        fs::write(root.join("src/main/kotlin/Main.kt"), "updated").unwrap();
+        let second = session.build(root, &model, root, false, None, &cancel).unwrap();
+        assert!(first.snapshot.is_dir());
+        assert!(second.snapshot.is_dir());
+        // Another mode can keep a superseded snapshot alive.
+        let test_record = cache.join("java-launch/records/nested/test.json");
+        fs::create_dir_all(test_record.parent().unwrap()).unwrap();
+        fs::write(&test_record, serde_json::to_vec(&first).unwrap()).unwrap();
+        drop(session);
+        assert!(first.snapshot.is_dir());
+        assert!(second.snapshot.is_dir());
+        let mut session = Session::new(cache.clone());
+        let reused = session.build(root, &model, root, false, None, &cancel).unwrap();
+        assert_eq!(reused.snapshot, second.snapshot);
+        fs::write(root.join("src/main/kotlin/Main.kt"), "third version").unwrap();
+        let third = session.build(root, &model, root, false, None, &cancel).unwrap();
+        assert!(second.snapshot.is_dir());
+        drop(session);
+        assert!(!second.snapshot.exists());
+        assert!(first.snapshot.is_dir());
+        assert!(third.snapshot.is_dir());
+        assert_eq!(fs::read_to_string(root.join("calls")).unwrap().lines().count(), 3);
+    }
+
+    #[test]
+    fn initial_sweep_only_removes_unreferenced_direct_snapshot_directories() {
+        let dir = tempfile::tempdir().unwrap();
+        let cache = dir.path().join("cache");
+        let snapshots = cache.join("java-launch/snapshots");
+        let retained = snapshots.join("launch-retained");
+        let orphan = snapshots.join("launch-orphan");
+        let other = snapshots.join("other");
+        let nested = other.join("launch-nested");
+        let outside = dir.path().join("launch-outside");
+        for path in [&retained, &orphan, &nested, &outside] {
+            fs::create_dir_all(path).unwrap();
+        }
+        fs::write(outside.join("classes"), "keep").unwrap();
+        std::os::unix::fs::symlink(&outside, snapshots.join("launch-link")).unwrap();
+        fs::write(snapshots.join("launch-file"), "keep").unwrap();
+        let record = cache.join("java-launch/records/deep/module/test.json");
+        fs::create_dir_all(record.parent().unwrap()).unwrap();
+        let outputs = Outputs { fingerprint: None, snapshot: retained.clone(), originals: Vec::new() };
+        fs::write(record, serde_json::to_vec(&outputs).unwrap()).unwrap();
+        let mut session = Session::new(cache);
+        session.initialize();
+        assert!(!orphan.exists());
+        assert!(retained.is_dir());
+        assert!(nested.is_dir());
+        assert!(outside.join("classes").is_file());
+        assert!(snapshots.join("launch-link").is_symlink());
+        assert!(snapshots.join("launch-file").is_file());
+        // Initialization must not sweep snapshots still in use by this session.
+        fs::create_dir_all(&orphan).unwrap();
+        session.initialize();
+        assert!(orphan.is_dir());
+        session.unreferenced.extend([outside.clone(), snapshots.join("../../launch-outside"), nested]);
+        drop(session);
+        assert!(outside.join("classes").is_file());
+        assert!(other.join("launch-nested").is_dir());
+    }
+
+    #[test]
+    fn failed_record_publish_retains_snapshot_until_session_drop() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let script = root.join("mvnw");
+        let mut text = fs::read_to_string(&script).unwrap();
+        text.push_str("rm cache/java-launch/records/main.json\nmkdir cache/java-launch/records/main.json\n");
+        fs::write(script, text).unwrap();
+        let cache = root.join("cache");
+        let mut session = Session::new(cache.clone());
+        assert!(session.build(root, &model, root, false, None, &CancellationToken::new()).is_err());
+        assert_eq!(session.unreferenced.len(), 1);
+        let snapshot = session.unreferenced[0].clone();
+        assert!(snapshot.join("0/Main.class").is_file());
+        drop(session);
+        assert!(!snapshot.exists());
+    }
+
+    #[test]
+    fn edits_during_build_do_not_publish_a_success_record() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let script = root.join("mvnw");
+        let mut text = fs::read_to_string(&script).unwrap();
+        text.push_str("echo edited-during-build >> src/main/kotlin/Main.kt\n");
+        fs::write(script, text).unwrap();
+        let cache = root.join("cache");
+        let mut session = Session::new(cache.clone());
+        let outputs = session.build(root, &model, root, false, None, &CancellationToken::new()).unwrap();
+        assert!(outputs.fingerprint.is_none());
+        assert_eq!(fs::read(cache.join("java-launch/records/main.json")).unwrap(), b"null");
+        assert!(outputs.snapshot.join("0/Main.class").is_file());
+        drop(session);
+        assert!(!outputs.snapshot.exists());
+    }
+    #[test]
+    fn deleting_the_last_mixed_source_keeps_maven_delegation_after_failure() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cache = root.join("cache");
+        let cancel = CancellationToken::new();
+        let mut session = Session::new(cache.clone());
+        let first = session.build(root, &model, root, false, None, &cancel).unwrap();
+        fs::remove_file(root.join("src/main/kotlin/Main.kt")).unwrap();
+        assert!(!compile::launch_has_non_java_sources(root, &model, root, false));
+        assert!(has_record(root, &cache, root));
+        assert!(session.build(root, &model, root, false, None, &cancel).is_err());
+        assert!(has_record(root, &cache, root));
+        fs::write(root.join("src/main/kotlin/Main.kt"), "restored").unwrap();
+        let restored = session.build(root, &model, root, false, None, &cancel).unwrap();
+        assert_ne!(first.snapshot, restored.snapshot);
+    }
+}
@@ -83,12 +83,18 @@ pub async fn lsp_implementations(
    result
 }

-/// Contents of a virtual document (library class, decompiled code) that a
-/// language server returned a non-`file:` URI for. Cached per project.
+/// Contents of a read-only language-server document, including JDT library
+/// classes and disk class files. Cached per project.
 pub async fn lsp_virtual_document(host: &Host, window: &str, uri: String) -> IdeResult<VirtualDocument> {
    host.project(window)?.lsp.virtual_document(&uri).await
 }

+/// Opens compiled classes through JDT, with project source taking priority on disk.
+pub async fn lsp_resolve_class_file(host: &Host, window: &str, path: std::path::PathBuf) -> IdeResult<String> {
+    let archive = ide_vfs::split_archive_path(&path);
+    host.project(window)?.lsp.java_class_file(&path, archive).await
+}
+
 /// References of the symbol at `pos`. `project_wide` also searches project files
 /// outside the language server's analysis scope; bulk scans over many symbols
 /// leave it off. Cancel with `cancel_request(request)`.
@@ -208,7 +214,7 @@ pub async fn lsp_format(
    range: Option<Range>,
    options: FormatOptions,
 ) -> IdeResult<Vec<TextEdit>> {
-    host.project(window)?.lsp.format(doc, range, options).await
+    crate::formatter::format(host, window, doc, range, options).await
 }

 pub async fn lsp_inlay_hints(host: &Host, window: &str, doc: DocId, range: Range) -> IdeResult<Vec<InlayHint>> {
@@ -263,7 +269,13 @@ pub fn lsp_resend_diagnostics(host: &Host, window: &str) -> IdeResult<()> {
 }

 pub async fn lsp_restart(host: &Host, window: &str, server: ServerId) -> IdeResult<()> {
-    host.project(window)?.lsp.restart(server).await
+    let project = host.project(window)?;
+    let java = project.lsp.servers().iter().any(|s| s.id == server && s.name == "jdtls");
+    project.lsp.restart(server).await?;
+    if java && let Some(bridge) = &project.kotlin_bridge {
+        bridge.schedule();
+    }
+    Ok(())
 }

 /// Applies a (previewed) workspace edit, e.g. after rename confirmation.
@@ -290,6 +302,58 @@ pub async fn lsp_execute_command(host: &Host, window: &str, doc: DocId, command:
    host.project(window)?.lsp.execute_command(doc, command).await
 }

+/// Resolves an interactive command without applying edits or executing it.
+pub async fn lsp_resolve_command(
+    host: &Host,
+    window: &str,
+    request: RequestId,
+    doc: DocId,
+    server: ServerId,
+    command: Command,
+    answers: Vec<FormAnswer>,
+) -> IdeResult<Option<CommandForm>> {
+    let lsp = host.project(window)?.lsp.clone();
+    let cancel = host.begin_request(request);
+    let result = lsp.resolve_command(doc, server, command, answers, cancel).await;
+    host.end_request(request);
+    result
+}
+
+/// Applies an explicitly invoked action after the interactive answers have been validated.
+pub async fn lsp_execute_code_action(
+    host: &Host,
+    window: &str,
+    request: RequestId,
+    doc: DocId,
+    action: CodeAction,
+    answers: Vec<FormAnswer>,
+) -> IdeResult<Vec<ide_core::IpcPath>> {
+    let project = host.project(window)?;
+    let cancel = host.begin_request(request);
+    let result = async {
+        if cancel.is_cancelled() {
+            return Err(ide_core::IdeError::cancelled());
+        }
+        if let Some(edit) = action.edit {
+            let documents = project.documents.clone();
+            tokio::task::spawn_blocking(move || apply_edit(&documents, &edit))
+                .await
+                .map_err(|e| ide_core::IdeError::internal(e.to_string()))??;
+        }
+        match action.command {
+            Some(command) => project
+                .lsp
+                .execute_action_command(doc, action.server, command, answers, cancel)
+                .await
+                .map(|paths| paths.into_iter().map(ide_core::IpcPath::from).collect()),
+            None => Ok(Vec::new()),
+        }
+    }
+    .await;
+    host.end_request(request);
+    result
+}
+
 /// Commands of this module the remote server answers.
 pub(crate) fn register(d: &mut Dispatcher) {
    d.add("lsp_completion", |c| async move {
@@ -315,6 +379,10 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("lsp_implementations", |c| async move {
        lsp_implementations(&c.host, &c.window, c.arg("request")?, c.arg("doc")?, c.arg("positions")?).await
    });
+    d.add(
+        "lsp_resolve_class_file",
+        |c| async move { lsp_resolve_class_file(&c.host, &c.window, c.arg("path")?).await },
+    );
    d.add("lsp_virtual_document", |c| async move { lsp_virtual_document(&c.host, &c.window, c.arg("uri")?).await });
    d.add("lsp_references", |c| async move {
        lsp_references(
@@ -374,6 +442,29 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("lsp_resend_diagnostics", |c| async move { lsp_resend_diagnostics(&c.host, &c.window) });
    d.add("lsp_restart", |c| async move { lsp_restart(&c.host, &c.window, c.arg("server")?).await });
    d.add("apply_workspace_edit", |c| async move { apply_workspace_edit(&c.host, &c.window, c.arg("edit")?) });
+    d.add("lsp_resolve_command", |c| async move {
+        lsp_resolve_command(
+            &c.host,
+            &c.window,
+            c.arg("request")?,
+            c.arg("doc")?,
+            c.arg("server")?,
+            c.arg("command")?,
+            c.arg("answers")?,
+        )
+        .await
+    });
+    d.add("lsp_execute_code_action", |c| async move {
+        lsp_execute_code_action(
+            &c.host,
+            &c.window,
+            c.arg("request")?,
+            c.arg("doc")?,
+            c.arg("action")?,
+            c.arg("answers")?,
+        )
+        .await
+    });
    d.add("lsp_execute_command", |c| async move {
        lsp_execute_command(&c.host, &c.window, c.arg("doc")?, c.arg("command")?).await
    });
@@ -172,8 +172,16 @@ pub fn set_settings(
        host.apply_proxy();
    }
    // A new interpreter / toolchain / server executable restarts the language servers it affects.
-    if ["languages", "tools", "languageServers"].iter().any(|k| key == *k || key.starts_with(&format!("{k}."))) {
+    let code_style = key == "editor" || key == "editor.codeStyle" || key.starts_with("editor.codeStyle.");
+    let toolchain = ["languages", "tools", "languageServers", "projectStructure"]
+        .iter()
+        .any(|k| key == *k || key.starts_with(&format!("{k}.")));
+    // Code style only reaches servers as settings (e.g. jdtls' formatter profile); builds don't depend on it.
+    if code_style || toolchain {
        for project in affected() {
+            if toolchain && let Some(bridge) = &project.kotlin_bridge {
+                bridge.schedule();
+            }
            let lsp = project.lsp.clone();
            host.runtime.spawn(async move { lsp.reconfigure().await });
        }
@@ -5,6 +5,78 @@ use crate::rpc::Dispatcher;
 use ide_core::{IdeError, IdeResult};
 use ide_run::RunConfig;

+fn application_cache(project: &crate::project::Project, id: &str) -> std::path::PathBuf {
+    use std::hash::{Hash, Hasher};
+    let mut hash = std::collections::hash_map::DefaultHasher::new();
+    id.hash(&mut hash);
+    project.cache_dir.join("application-update").join(format!("{:x}", hash.finish()))
+}
+
+pub async fn run_application_build(
+    host: &Host,
+    window: &str,
+    config: RunConfig,
+    module: std::path::PathBuf,
+) -> IdeResult<RunConfig> {
+    host.require_trust(window)?;
+    if config.kind != "spring-boot" || config.extras.target.as_ref().is_some_and(|t| !t.is_empty()) {
+        return Err(IdeError::invalid("Application resource updates require a local Spring Boot configuration"));
+    }
+    let project = host.project(window)?;
+    tokio::task::spawn_blocking(move || {
+        let model = crate::ops::build::load(&project.root, &project.build_cache_dir(), &project.settings.effective());
+        let plan = ide_build::application_update::plan(
+            &project.root,
+            &model,
+            &module,
+            &application_cache(&project, &config.id),
+        )?;
+        let mut env = plan.env;
+        env.extend(config.env);
+        Ok(RunConfig {
+            id: format!("application-build:{}", config.id),
+            name: format!("Update {}", config.name),
+            kind: plan.kind.into(),
+            command: plan.command,
+            args: plan.args,
+            cwd: Some(project.root.join(plan.cwd).into()),
+            env,
+            detected: false,
+            is_test: false,
+            debug_adapter: None,
+            allow_parallel: false,
+            extras: ide_run::RunExtras {
+                include_system_env: config.extras.include_system_env,
+                env_files: config.extras.env_files,
+                ..Default::default()
+            },
+        })
+    })
+    .await
+    .map_err(|e| IdeError::internal(e.to_string()))?
+}
+
+pub async fn run_application_publish(
+    host: &Host,
+    window: &str,
+    config: RunConfig,
+    class_paths: Vec<String>,
+    main_class: String,
+) -> IdeResult<()> {
+    host.require_trust(window)?;
+    let project = host.project(window)?;
+    tokio::task::spawn_blocking(move || {
+        ide_build::application_update::publish(
+            &project.root,
+            &application_cache(&project, &config.id),
+            &class_paths,
+            &main_class,
+        )
+    })
+    .await
+    .map_err(|e| IdeError::internal(e.to_string()))?
+}
+
 /// Configuration templates: per-type defaults applied to new configurations.
 pub fn run_templates(host: &Host, window: &str) -> IdeResult<Vec<RunConfig>> {
    let root = host.project(window)?.root.clone();
@@ -134,6 +206,12 @@ pub async fn run_tomcat_update(host: &Host, window: &str, config: RunConfig, mod

 /// Commands of this module the remote server answers.
 pub(crate) fn register(d: &mut Dispatcher) {
+    d.add("run_application_build", |c| async move {
+        run_application_build(&c.host, &c.window, c.arg("config")?, c.arg("module")?).await
+    });
+    d.add("run_application_publish", |c| async move {
+        run_application_publish(&c.host, &c.window, c.arg("config")?, c.arg("classPaths")?, c.arg("mainClass")?).await
+    });
    d.add("run_tomcat_home", |c| async move { run_tomcat_home(&c.host, &c.window, c.arg("home")?).await });
    d.add("run_tomcat_artifacts", |c| async move { run_tomcat_artifacts(&c.host, &c.window).await });
    d.add("run_tomcat_build", |c| async move { run_tomcat_build(&c.host, &c.window, c.arg("config")?).await });
@@ -16,11 +16,15 @@ pub fn spawn(
        options.args.clear();
        options.env = global.env;
    }
-    // Python › "Activate virtualenv": typed into the new shell, like PyCharm.
-    let activation =
-        host.project(window).ok().filter(|p| p.is_trusted()).and_then(|p| {
-            ide_sdk::apply::terminal_activation(&p.root, &p.settings.effective(), options.shell.as_deref())
-        });
+    let (shell, args) = ide_terminal::resolve_shell(options.shell.as_deref(), &options.args);
+    options.shell = Some(shell.clone());
+    options.args = args;
+    // Python › "Activate virtualenv": typed into the same shell the PTY starts.
+    let activation = host
+        .project(window)
+        .ok()
+        .filter(|p| p.is_trusted())
+        .and_then(|p| ide_sdk::apply::terminal_activation(&p.root, &p.settings.effective(), &shell));
    let info = host.terminals.spawn(options, host.window_sink(window), Box::new(move |chunk| on_output(chunk)))?;
    if let Some(line) = activation {
        let _ = host.terminals.write(info.id, &format!(" {line}\r"));
@@ -100,11 +100,11 @@ pub fn jdk_download_vendors(_host: &Host, _window: &str) -> Vec<JdkVendor> {
 /// Java versions `vendor` publishes; cancellable with `cancel_request(request)`.
 pub async fn jdk_download_releases(
    host: &Host,
-    window: &str,
+    _window: &str,
    vendor: String,
    request: RequestId,
 ) -> IdeResult<JdkReleases> {
-    let tools = tools(host, window)?;
+    let tools = Tools::new(&host.data_dir);
    let cancel = host.begin_request(request);
    let result = tokio::task::spawn_blocking(move || tools.jdk_releases(&vendor, &cancel)).await.map_err(join_err);
    host.end_request(request);
@@ -123,14 +123,14 @@ pub fn jdk_download_location(host: &Host, _window: &str) -> IdeResult<ide_core::
 #[allow(clippy::too_many_arguments)]
 pub async fn jdk_download(
    host: &Host,
-    window: &str,
+    _window: &str,
    vendor: String,
    version: u32,
    location: Option<PathBuf>,
    request: RequestId,
    on_event: Channel<InstallEvent>,
 ) -> IdeResult<Sdk> {
-    let tools = tools(host, window)?;
+    let tools = Tools::new(&host.data_dir);
    let location = location.filter(|p| !p.as_os_str().is_empty());
    let cancel = host.begin_request(request);
    let result = tokio::task::spawn_blocking(move || {
@@ -746,6 +746,33 @@ pub async fn vcs_remove_worktree(
    blocking(move || project.with_repo_at(repo.as_deref(), |r| r.remove_worktree(&path, force))).await
 }

+pub async fn vcs_compare_scope(host: &Host, window: &str, paths: Vec<PathBuf>) -> IdeResult<CompareScope> {
+    let project = host.project(window)?;
+    blocking(move || Ok(project.repos().compare_scope(&paths))).await
+}
+
+pub async fn vcs_compare_paths(
+    host: &Host,
+    window: &str,
+    paths: Vec<PathBuf>,
+    revision: String,
+    repositories: Option<Vec<PathBuf>>,
+    request: RequestId,
+) -> IdeResult<CompareResult> {
+    let project = host.project(window)?;
+    let cancel = host.begin_request(request);
+    let result = blocking(move || {
+        let settings = project.settings.effective();
+        if project.is_trusted() {
+            apply_git_executable(&settings);
+        }
+        project.repos().compare_paths(&paths, &revision, repositories.as_deref(), &cancel)
+    })
+    .await;
+    host.end_request(request);
+    result
+}
+
 /// Compare with Local: tracked files that differ between `rev` and the working tree.
 pub async fn vcs_diff_with_worktree(
    host: &Host,
@@ -1040,6 +1067,18 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("vcs_remove_worktree", |c| async move {
        vcs_remove_worktree(&c.host, &c.window, c.arg("repo")?, c.arg("path")?, c.arg("force")?).await
    });
+    d.add("vcs_compare_scope", |c| async move { vcs_compare_scope(&c.host, &c.window, c.arg("paths")?).await });
+    d.add("vcs_compare_paths", |c| async move {
+        vcs_compare_paths(
+            &c.host,
+            &c.window,
+            c.arg("paths")?,
+            c.arg("revision")?,
+            c.arg("repositories")?,
+            c.arg("request")?,
+        )
+        .await
+    });
    d.add("vcs_diff_with_worktree", |c| async move {
        vcs_diff_with_worktree(&c.host, &c.window, c.arg("repo")?, c.arg("rev")?).await
    });
@@ -42,6 +42,8 @@ pub struct Project {
    pub detected_roots: Arc<RwLock<Vec<SourceFolder>>>,
    /// Per-project cache directory (build tool sync results…).
    pub cache_dir: PathBuf,
+    /// Superseded launch snapshots retained until this project session ends.
+    pub(crate) java_launch_snapshots: Mutex<crate::ops::java::cache::Session>,
    /// Database tool window: data sources and their connections.
    pub db: Arc<ide_db::DbManager>,
    /// HTTP Client responses (IDEA's `.idea/httpRequests`), in the app data dir.
@@ -50,6 +52,7 @@ pub struct Project {
    pub agents: Arc<ide_agent::AgentManager>,
    /// Native notebooks and owned kernels, scoped to this project incarnation.
    pub notebooks: Arc<crate::notebook::NotebookService>,
+    pub(crate) kotlin_bridge: Option<Arc<crate::kotlin_bridge::KotlinBridge>>,
    pub(crate) watcher: Watcher,
    /// Watchers of the Project Structure content roots outside the project folder.
    pub(crate) content_watchers: Mutex<Vec<(PathBuf, Watcher)>>,
@@ -126,6 +129,8 @@ impl Host {
            let root = root.clone();
            let data_dir = self.data_dir.clone();
            let config_dir = self.config_dir.clone();
+            let sink = sink.clone();
+            let formatter_problem = std::sync::Mutex::new(None);
            lsp.set_config_hook(Box::new(move |cfg, server_root| {
                let member = ide_workspace::workspace::Workspace::load(&root).ok().flatten().and_then(|w| {
                    w.projects.into_iter().filter(|p| server_root.starts_with(p)).max_by_key(|p| p.components().count())
@@ -139,8 +144,40 @@ impl Host {
                ide_sdk::apply::configure_server(cfg, root, server_root, &effective);
                ide_sdk::java::cap_java_home(cfg, &ide_sdk::java::installed_jdks());
                if cfg.name == "jdtls" {
-                    let bundles: Vec<PathBuf> =
-                        ide_tools::managed_bundle(&data_dir, "java-debug").into_iter().collect();
+                    let problem = ide_lsp::jdtls::configure_formatter(
+                        cfg,
+                        effective.editor.code_style.languages.get("java"),
+                        root,
+                        &data_dir,
+                        effective.language_servers.get("jdtls"),
+                    )
+                    .err()
+                    .map(|e| e.to_string());
+                    let mut previous = formatter_problem.lock().unwrap();
+                    if problem != *previous {
+                        if let Some(body) = &problem {
+                            sink.emit(IdeEvent::Notify {
+                                level: ide_core::event::NotifyLevel::Warning,
+                                title: "Java formatter configuration unavailable".into(),
+                                body: Some(body.clone()),
+                            });
+                        }
+                        *previous = problem;
+                    }
+                    drop(previous);
+                    ide_lsp::jdtls::configure_source_paths(
+                        cfg,
+                        ide_workspace::roots::unmanaged_java_source_paths(
+                            root,
+                            server_root,
+                            &effective.project_structure,
+                        ),
+                    );
+                    let bundles: Vec<PathBuf> = ide_tools::managed_bundle(&data_dir, "java-debug")
+                        .into_iter()
+                        .chain(ide_sdk::java::usages_bundle(&data_dir))
+                        .chain(ide_sdk::java::kotlin_bridge_bundle(&data_dir))
+                        .collect();
                    let min_java = ide_sdk::java::jdtls_min_java(cfg);
                    let jdks = ide_sdk::java::jdtls_jdks(min_java, &data_dir);
                    let lombok = ide_sdk::lombok::lombok_agent(
@@ -216,11 +253,22 @@ impl Host {
            trusted: trusted.clone(),
        }));

+        let kotlin_bridge = crate::kotlin_bridge::KotlinBridge::new(
+            root.clone(),
+            self.data_dir.join("cache").join(&project_key).join("build"),
+            &self.data_dir,
+            settings.clone(),
+            lsp.clone(),
+            sink.clone(),
+            trusted.clone(),
+        );
+        documents.add_observer(kotlin_bridge.clone());
        let repos = Arc::new(RwLock::new(Repos::enclosing(&root)?));
        for repo in repos.read().all() {
            repo.set_execution_allowed(trusted.load(Ordering::Acquire));
        }
        let watcher = {
+            let kotlin_bridge = kotlin_bridge.clone();
            let repos = repos.clone();
            let settings = settings.clone();
            let index = index.clone();
@@ -241,6 +289,7 @@ impl Host {
                Box::new(move |batch| {
                    let changed: Vec<PathBuf> = batch.created.iter().chain(&batch.modified).cloned().collect();
                    index.update(&changed, &batch.removed);
+                    kotlin_bridge.files_changed(changed.iter().chain(&batch.removed));
                    lsp.project_files_changed(batch.created.iter().chain(&batch.removed));
                    // Atomic saves by external tools surface as `created`.
                    documents.on_disk_changed(&changed);
@@ -320,7 +369,7 @@ impl Host {
        let content_watchers = extra_roots
            .iter()
            .filter_map(|r| {
-                let w = content_root_watcher(r, &excludes, &sink, &index, &documents, &history)?;
+                let w = content_root_watcher(r, &excludes, &sink, &index, &documents, &history, Some(&kotlin_bridge))?;
                Some((r.clone(), w))
            })
            .collect();
@@ -356,10 +405,14 @@ impl Host {
            syntax,
            detected_roots,
            cache_dir: self.data_dir.join("cache").join(&project_key),
+            java_launch_snapshots: Mutex::new(crate::ops::java::cache::Session::new(
+                self.data_dir.join("cache").join(&project_key).join("build"),
+            )),
            db,
            http_history,
            agents,
            notebooks,
+            kotlin_bridge: Some(kotlin_bridge),
            watcher,
            content_watchers: Mutex::new(content_watchers),
            _scratch_watcher: scratch_watcher,
@@ -378,6 +431,9 @@ impl Host {
            }));
        }
        self.insert_project(window, project.clone());
+        if let Some(bridge) = &project.kotlin_bridge {
+            bridge.start(&self.runtime);
+        }
        if let Some(cmd) = post_start {
            self.environment.spawn_post_start(cmd, project.root.clone(), project.sink.clone());
        }
@@ -471,10 +527,14 @@ impl Host {
            syntax,
            detected_roots: Arc::default(),
            cache_dir: self.data_dir.join("cache").join(&project_key),
+            java_launch_snapshots: Mutex::new(crate::ops::java::cache::Session::new(
+                self.data_dir.join("cache").join(&project_key).join("build"),
+            )),
            db,
            http_history,
            agents,
            notebooks,
+            kotlin_bridge: None,
            watcher,
            content_watchers: Mutex::new(Vec::new()),
            _scratch_watcher: None,
@@ -768,9 +828,15 @@ impl Project {
            if watchers.iter().any(|(p, _)| *p == r) {
                continue;
            }
-            if let Some(w) =
-                content_root_watcher(&r, &excludes, &self.sink, &self.index, &self.documents, &self.history)
-            {
+            if let Some(w) = content_root_watcher(
+                &r,
+                &excludes,
+                &self.sink,
+                &self.index,
+                &self.documents,
+                &self.history,
+                self.kotlin_bridge.as_ref(),
+            ) {
                watchers.push((r, w));
            }
        }
@@ -902,7 +968,9 @@ fn content_root_watcher(
    index: &Arc<ProjectIndex>,
    documents: &Arc<Documents>,
    history: &Arc<LocalHistory>,
+    kotlin_bridge: Option<&Arc<crate::kotlin_bridge::KotlinBridge>>,
 ) -> Option<Watcher> {
+    let kotlin_bridge = kotlin_bridge.cloned();
    let (index, documents, history) = (index.clone(), documents.clone(), history.clone());
    Watcher::start(
        dir,
@@ -911,6 +979,9 @@ fn content_root_watcher(
        Box::new(move |batch| {
            let changed: Vec<PathBuf> = batch.created.iter().chain(&batch.modified).cloned().collect();
            index.update(&changed, &batch.removed);
+            if let Some(bridge) = &kotlin_bridge {
+                bridge.files_changed(changed.iter().chain(&batch.removed));
+            }
            documents.on_disk_changed(&changed);
            record_external_changes(&history, &changed, &batch.removed);
        }),
@@ -179,6 +179,7 @@ impl Dispatcher {
        })
        .add("cancel_task", |c| async move { Ok(ide_core::task::cancel(c.arg::<TaskId>("id")?)) })
        .add("fs_read_dir", |c| async move { ops::fs::read_dir(&c.host, &c.window, c.arg("path")?) })
+        .add("fs_entry_kind", |c| async move { ops::fs::entry_kind(&c.host, c.arg("path")?).await })
        .add("fs_create_file", |c| async move { ops::fs::create_file(&c.host, &c.window, c.arg("path")?) })
        .add("fs_create_file_bytes", |c| async move {
            ops::fs::create_file_bytes(&c.host, c.arg("path")?, c.arg("data")?).await
@@ -190,6 +191,28 @@ impl Dispatcher {
        })
        .add("fs_delete", |c| async move { ops::fs::delete(&c.host, &c.window, c.arg("path")?).await })
        .add("fs_copy", |c| async move { ops::fs::copy(&c.host, c.arg("from")?, c.arg("to")?).await })
+        .add("fs_copy_merge", |c| async move {
+            ops::fs::copy_merge(
+                &c.host,
+                &c.window,
+                c.arg("sourceRoot")?,
+                c.arg("destinationRoot")?,
+                c.arg("path")?,
+                c.arg("overwrite")?,
+            )
+            .await
+        })
+        .add("fs_compare_directories", |c| async move {
+            ops::fs::compare_directories(
+                &c.host,
+                &c.window,
+                c.arg("left")?,
+                c.arg("right")?,
+                c.arg("request")?,
+                c.sender("onProgress")?,
+            )
+            .await
+        })
        .add("fs_read_text", |c| async move { ops::fs::read_text(&c.host, &c.window, c.arg("path")?).await })
        .add("doc_open", |c| async move { ops::doc::open(&c.host, &c.window, c.arg("path")?).await })
        .add("doc_close", |c| async move { ops::doc::close(&c.host, &c.window, c.arg("doc")?) })
@@ -106,6 +106,9 @@ impl crate::Host {
            if previous == trusted {
                continue;
            }
+            if let Some(bridge) = &project.kotlin_bridge {
+                bridge.schedule();
+            }
            if !trusted {
                project.lsp.set_execution_allowed(false);
            }
@@ -175,6 +178,30 @@ pub fn restricted_command_allowed(cmd: &str) -> bool {
    matches!(
        cmd,
        "app_info"
+            | "app_build_info"
+            | "app_log_location"
+            | "app_check_update"
+            | "app_startup_update_check"
+            | "app_install_update"
+            | "caches_schedule_invalidation"
+            | "clear_caches"
+            | "clipboard_file_list"
+            | "clipboard_has_files"
+            | "clipboard_set_file_list"
+            | "jdk_download_vendors"
+            | "jdk_download_releases"
+            | "jdk_download_location"
+            | "jdk_download"
+            | "run_system_env"
+            | "run_gradle_jvm_args_script"
+            | "proxy_check_connection"
+            | "docker_settings"
+            | "docker_save_settings"
+            | "docker_set_registry_password"
+            | "docker_run_env"
+            | "db_console_path"
+            | "db_export_file"
+            | "vcs_write_patch"
            | "app_metrics"
            | "app_quit"
            | "app_cancel_quit"
@@ -235,6 +262,7 @@ pub fn restricted_command_allowed(cmd: &str) -> bool {
            | "agent_registry_remove"
            | "coverage_import"
            | "system_font_families"
+            | "user_font_data"
            | "plugin_subscribe"
            | "plugin_list"
            | "plugin_set_active_file"
@@ -276,6 +304,8 @@ pub fn restricted_command_allowed(cmd: &str) -> bool {
            | "vcs_remotes"
            | "vcs_worktrees"
            | "vcs_diff_with_worktree"
+            | "vcs_compare_scope"
+            | "vcs_compare_paths"
            | "vcs_diff_revisions"
            | "vcs_merge_base"
            | "vcs_shelves"
@@ -104,7 +104,7 @@ async fn properties_search_git_and_document_coordinates_agree() {
        "main",
        opened.id,
        opened.version,
-        ChangeSet { changes: vec![TextChange { from: 10, to: 16, insert: "世界".into() }] },
+        ChangeSet { changes: vec![TextChange { from: 10, to: 16, insert: r"\u4E16\u754C".into() }] },
    )
    .unwrap();
    let hunks = vcs::vcs_line_hunks(&host, "main", path.clone()).await.unwrap();
@@ -129,7 +129,7 @@ async fn properties_search_git_and_document_coordinates_agree() {
    assert!(project.documents.snapshot(opened.id).unwrap().version > snap.version);
    assert!(vcs::vcs_line_hunks(&host, "main", path.clone()).await.unwrap().is_empty());
    // Partial commits identify hunks in displayed line coordinates as well.
-    let partial_text = displayed.replace("target", "世界").replace("logical", "changed");
+    let partial_text = displayed.replace("target", r"\u4E16\u754C").replace("logical", "changed");
    project.documents.replace_all(opened.id, &partial_text).unwrap();
    doc::save(&host, "main", opened.id).await.unwrap();
    let hunks = ide_vcs::diff_hunks(displayed, &partial_text);
@@ -169,7 +169,7 @@ async fn properties_search_git_and_document_coordinates_agree() {
        "main",
        RequestId(520),
        query,
-        "世界".into(),
+        r"\u4E16\u754C".into(),
        false,
        vec![ide_search::ReplaceTarget {
            path: closed_path.clone().into(),
@@ -181,5 +181,6 @@ async fn properties_search_git_and_document_coordinates_agree() {
    .unwrap();
    assert_eq!(std::fs::read_to_string(&closed_path).unwrap(), r"value=\u4F60\u597D\uD83D\uDE00\u4E16\u754C");
    assert!(project.documents.by_path(&closed_path).is_none());
+    assert_eq!(project.text_of(&closed_path).unwrap(), "value=你好😀世界");
    host.close_project("main");
 }
@@ -94,6 +94,39 @@ async fn serves_projects_files_documents_search_and_runs() {
    let entries = invoke(&peer, "fs_read_dir", json!({ "path": project })).await.unwrap();
    assert!(entries.as_array().unwrap().iter().any(|e| e["name"] == "src"), "{entries}");

+    // Directory comparisons, streamed progress and confirmed copies share the remote filesystem.
+    let left = project.join("compare-left");
+    let right = project.join("compare-right");
+    std::fs::create_dir_all(&left).unwrap();
+    std::fs::create_dir_all(&right).unwrap();
+    std::fs::write(left.join("中文.bin"), [0, 255, 1]).unwrap();
+    std::fs::write(right.join("中文.bin"), [0, 254, 1]).unwrap();
+    assert_eq!(invoke(&peer, "fs_entry_kind", json!({"path": left})).await.unwrap(), "dir");
+    assert_eq!(invoke(&peer, "fs_entry_kind", json!({"path": left.join("中文.bin")})).await.unwrap(), "file");
+    let compare_args =
+        |request| json!({"left": left, "right": right, "request": request, "onProgress": {"$channel": 520}});
+    let rows = invoke(&peer, "fs_compare_directories", compare_args(520)).await.unwrap();
+    assert_eq!(rows[0]["status"], "different");
+    assert!(client.channels.lock().iter().any(|c| c.id == 520 && c.data["compared"] == 1));
+    let copy_args =
+        |overwrite| json!({"sourceRoot": left, "destinationRoot": right, "path": "中文.bin", "overwrite": overwrite});
+    let error = invoke(&peer, "fs_copy_merge", copy_args(false)).await.unwrap_err();
+    assert_eq!(error.kind, ide_core::error::ErrorKind::AlreadyExists);
+    invoke(&peer, "fs_copy_merge", copy_args(true)).await.unwrap();
+    let rows = invoke(&peer, "fs_compare_directories", compare_args(521)).await.unwrap();
+    assert_eq!(rows[0]["status"], "equal");
+    invoke(&peer, "cancel_request", json!({"id": 522})).await.unwrap();
+    let error = invoke(&peer, "fs_compare_directories", compare_args(522)).await.unwrap_err();
+    assert_eq!(error.kind, ide_core::error::ErrorKind::Cancelled);
+    let error = invoke(
+        &peer,
+        "fs_copy_merge",
+        json!({"sourceRoot": left, "destinationRoot": right, "path": "../escape", "overwrite": true}),
+    )
+    .await
+    .unwrap_err();
+    assert_eq!(error.kind, ide_core::error::ErrorKind::InvalidInput);
+
    // JVM icons use the same read-only protocol as local windows.
    let java = project.join("src/Foo.java");
    let kotlin = project.join("src/Singleton.kt");
@@ -0,0 +1,62 @@
+//! Own test process: the inherited shell deliberately differs from the login shell.
+#![cfg(unix)]
+
+use ide_core::NullSink;
+use ide_host::{Host, HostConfig, ops};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+#[test]
+fn terminal_activation_uses_the_resolved_default_shell() {
+    // SAFETY: no runtime or worker threads have been started.
+    unsafe { std::env::set_var("SHELL", "/not-the-terminal/docker") };
+    let tmp = tempfile::tempdir().unwrap();
+    let root = dunce::canonicalize(tmp.path()).unwrap().join("project");
+    let bin = root.join(".venv/bin");
+    std::fs::create_dir_all(&bin).unwrap();
+    std::fs::write(root.join(".venv/pyvenv.cfg"), "home = /usr/bin\n").unwrap();
+    std::fs::write(bin.join("python"), "").unwrap();
+    for script in ["activate", "activate.fish", "activate.csh", "activate.nu", "Activate.ps1"] {
+        std::fs::write(bin.join(script), "echo activated > activation.marker\n").unwrap();
+    }
+    let runtime = tokio::runtime::Builder::new_multi_thread().worker_threads(2).enable_all().build().unwrap();
+    runtime.block_on(async {
+        let host = Arc::new(Host::new(HostConfig {
+            config_dir: tmp.path().join("config"),
+            data_dir: tmp.path().join("data"),
+            languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+            syntax: Arc::default(),
+            sink_for: Box::new(|_| Arc::new(NullSink)),
+            owner: |w| w,
+            runtime: tokio::runtime::Handle::current(),
+            project_environment: false,
+        }));
+        host.trust.decide(&root, true, false).unwrap();
+        host.open_project("main", &root).unwrap();
+        for shell in [None, Some("".to_owned()), Some(" \t ".to_owned())] {
+            let terminal = ops::term::spawn(
+                &host,
+                "main",
+                ide_terminal::TerminalOptions {
+                    cwd: root.clone().into(),
+                    shell,
+                    args: vec![],
+                    env: Default::default(),
+                    cols: 80,
+                    rows: 24,
+                    shell_integration: false,
+                },
+                Arc::new(|_| {}),
+            )
+            .unwrap();
+            let deadline = Instant::now() + Duration::from_secs(10);
+            while !std::fs::read_to_string(root.join("activation.marker")).is_ok_and(|s| s.trim() == "activated") {
+                assert!(Instant::now() < deadline, "default terminal shell must run the activation script");
+                tokio::time::sleep(Duration::from_millis(20)).await;
+            }
+            host.terminals.kill(terminal.id).unwrap();
+            std::fs::remove_file(root.join("activation.marker")).unwrap();
+        }
+        host.shutdown().await;
+    });
+}
@@ -20,6 +20,94 @@ fn host(base: &Path, environment: bool) -> Arc<Host> {
    }))
 }

+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn application_commands_work_in_restricted_projects_and_without_a_project() {
+    let tmp = tempfile::tempdir().unwrap();
+    let root = tmp.path().join("project");
+    std::fs::create_dir(&root).unwrap();
+    let host = host(&tmp.path().join("app"), false);
+    assert!(host.project("welcome").is_err());
+    assert!(ide_host::ops::project::roots(&host, "welcome").is_err());
+    assert!(!host.open_project("main", &root).unwrap().is_trusted());
+    for command in [
+        "app_info",
+        "app_build_info",
+        "app_log_location",
+        "app_check_update",
+        "app_startup_update_check",
+        "app_install_update",
+        "caches_schedule_invalidation",
+        "clear_caches",
+        "clipboard_file_list",
+        "clipboard_has_files",
+        "clipboard_set_file_list",
+        "jdk_download_vendors",
+        "jdk_download_releases",
+        "jdk_download_location",
+        "jdk_download",
+        "run_system_env",
+        "run_gradle_jvm_args_script",
+        "proxy_check_connection",
+        "docker_settings",
+        "docker_save_settings",
+        "docker_set_registry_password",
+        "docker_run_env",
+        "db_console_path",
+        "db_export_file",
+        "vcs_write_patch",
+    ] {
+        assert!(ide_host::trust::restricted_command_allowed(command), "{command}");
+        for window in ["main", "welcome"] {
+            assert!(host.authorize_command(window, command).is_ok(), "{window}: {command}");
+        }
+    }
+    for command in [
+        "run_start",
+        "build_sync",
+        "debug_start",
+        "sdk_detect",
+        "tools_list",
+        "tools_install",
+        "tools_uninstall",
+        "plugin_install_dir",
+        "plugin_reload",
+        "vcs_git_version",
+        "docker_compose_op",
+        "db_execute",
+        "unknown_command",
+    ] {
+        assert!(!ide_host::trust::restricted_command_allowed(command), "{command}");
+        for window in ["main", "welcome"] {
+            assert!(host.authorize_command(window, command).is_err(), "{window}: {command}");
+        }
+    }
+    // These requests validate the vendor before any network access, independently of project trust.
+    for window in ["main", "welcome"] {
+        let error = ide_host::ops::tools::jdk_download_releases(
+            &host,
+            window,
+            "unknown-vendor".into(),
+            ide_core::RequestId(901),
+        )
+        .await
+        .unwrap_err();
+        assert_eq!(error.kind, ide_core::error::ErrorKind::InvalidInput);
+        let error = ide_host::ops::tools::jdk_download(
+            &host,
+            window,
+            "unknown-vendor".into(),
+            25,
+            None,
+            ide_core::RequestId(902),
+            ide_host::ops::Channel::new(|_| {}),
+        )
+        .await
+        .unwrap_err();
+        assert_eq!(error.kind, ide_core::error::ErrorKind::InvalidInput);
+    }
+    host.shutdown().await;
+}
+
 #[test]
 fn persists_user_decisions_locations_revocation_and_one_time_migration() {
    let tmp = tempfile::tempdir().unwrap();
@@ -53,6 +53,19 @@ pub struct LanguageConfig {
    pub language_servers: Vec<LanguageServerConfig>,
    #[serde(default)]
    pub debugger: Option<DebuggerConfig>,
+    /// External formatter used when no language server can format, or selected in settings.
+    #[serde(default)]
+    pub formatter: Option<FormatterConfig>,
+}
+
+/// An external formatting tool and its language-specific parser.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub struct FormatterConfig {
+    pub tool: String,
+    pub parser: String,
+    #[serde(default)]
+    pub range: bool,
 }

 /// A CodeMirror mode for the files of a framework's projects.
@@ -209,8 +209,9 @@ impl SyntaxCache {
            |m| &mut m.folding,
            || {
                self.with_tree(doc, lang, version, text, |g, tree, text| {
-                    Some(folding::folding(g.spec, g.kinds(), tree, text))
+                    Some(folding::folding(g.spec, g.kinds(), tree, text, self.syntax.comment_tokens(lang)))
                })
+                .or_else(|| Some(self.syntax.custom_folding(lang, text)))
            },
        )
    }
@@ -2,7 +2,7 @@
 //! comment runs, import runs and `region` / `endregion` marker comments.

 use super::grammars::Spec;
-use crate::{FoldKind, FoldRange};
+use crate::{FoldKind, FoldRange, LanguageConfig};
 use tree_sitter::{Language, Node, Tree, TreeCursor};

 const PAIRS: &[(&str, &str)] = &[("{", "}"), ("[", "]"), ("(", ")"), ("#{", "}"), ("${", "}"), ("@{", "}")];
@@ -85,7 +85,25 @@ impl KindTable {
    }
 }

-pub(crate) fn folding(spec: &Spec, kinds: &KindTable, tree: &Tree, text: &str) -> Vec<FoldRange> {
+#[derive(Default)]
+pub(super) struct CommentTokens {
+    line: Option<String>,
+    block: Option<(String, String)>,
+}
+
+impl From<&LanguageConfig> for CommentTokens {
+    fn from(config: &LanguageConfig) -> Self {
+        Self { line: config.line_comment.clone(), block: config.block_comment.clone() }
+    }
+}
+
+pub(super) fn folding(
+    spec: &Spec,
+    kinds: &KindTable,
+    tree: &Tree,
+    text: &str,
+    tokens: &CommentTokens,
+) -> Vec<FoldRange> {
    let mut out: Vec<FoldRange> = Vec::new();
    let mut comments: Vec<Comment> = Vec::new();
    let mut cursor = tree.walk();
@@ -96,7 +114,7 @@ pub(crate) fn folding(spec: &Spec, kinds: &KindTable, tree: &Tree, text: &str) -
                start_row: start,
                end_row: last_content_row(&node, text),
                own_line: own_line(text, node.start_byte(), node.start_position().column),
-                marker: region_marker(text.get(node.start_byte()..node.end_byte()).unwrap_or_default()),
+                marker: region_marker(text.get(node.start_byte()..node.end_byte()).unwrap_or_default(), tokens),
            });
            return true;
        }
@@ -185,7 +203,7 @@ fn visit(cursor: &mut TreeCursor, mut f: impl FnMut(Node) -> bool) {
 }

 pub(crate) fn is_comment(kind: &str) -> bool {
-    kind.contains("comment")
+    kind.contains("comment") || kind == "Comment"
 }

 /// Row of the closing token when `node` is delimited by a matching bracket pair.
@@ -220,21 +238,64 @@ fn own_line(text: &str, byte: usize, column: usize) -> bool {
 }

 /// `Some(true)` for a region start marker, `Some(false)` for an end marker.
-fn region_marker(comment: &str) -> Option<bool> {
-    let body = comment
-        .trim_start_matches(['/', '*', '#', '-', ';', '%', '!', '<', ' ', '\t'])
-        .trim_start_matches("--")
-        .trim_start();
-    let lower = body.get(..body.len().min(32))?.to_ascii_lowercase();
-    if lower.starts_with("endregion") || lower.starts_with("#endregion") || lower.starts_with("</editor-fold") {
+/// Strip whole configured delimiters, preserving the `<` in editor-fold tags.
+pub(super) fn region_marker(comment: &str, tokens: &CommentTokens) -> Option<bool> {
+    let comment = comment.trim();
+    let body = if let Some((open, close)) = &tokens.block
+        && let Some(body) = comment.strip_prefix(open.as_str())
+    {
+        let body = body.trim_end().strip_suffix(close.as_str())?;
+        if open == "/*" { body.trim_start_matches('*') } else { body }
+    } else if let Some(open) = &tokens.line
+        && let Some(body) = comment.strip_prefix(open.as_str())
+    {
+        match open.as_str() {
+            "//" => body.trim_start_matches('/'),
+            ";" => body.trim_start_matches(';'),
+            _ => body,
+        }
+    } else {
+        return None;
+    };
+    let body = body.trim();
+    if body.contains(['\n', '\r']) {
+        return None;
+    }
+    let lower = body.to_ascii_lowercase();
+    let region = lower.strip_prefix('#').unwrap_or(&lower);
+    let boundary = |tail: &str| !tail.starts_with(|c: char| c.is_ascii_alphanumeric() || c == '_');
+    if region.strip_prefix("endregion").is_some_and(boundary)
+        || lower
+            .strip_prefix("</editor-fold")
+            .and_then(|tail| tail.strip_suffix('>'))
+            .is_some_and(|tail| tail.trim().is_empty())
+    {
        Some(false)
-    } else if lower.starts_with("region") || lower.starts_with("#region") || lower.starts_with("<editor-fold") {
+    } else if region.strip_prefix("region").is_some_and(boundary)
+        || lower.strip_prefix("<editor-fold").is_some_and(|tail| boundary(tail) && tail.contains('>'))
+    {
        Some(true)
    } else {
        None
    }
 }

+/// Languages without a bundled grammar still support own-line custom markers.
+pub(super) fn custom_folding(text: &str, tokens: &CommentTokens) -> Vec<FoldRange> {
+    let comments: Vec<_> = text
+        .lines()
+        .enumerate()
+        .filter_map(|(row, line)| {
+            let marker = region_marker(line, tokens)?;
+            Some(Comment { start_row: row, end_row: row, own_line: true, marker: Some(marker) })
+        })
+        .collect();
+    let mut out = Vec::new();
+    comment_folds(&comments, &mut out);
+    out.sort_by_key(|f| f.start_line);
+    out
+}
+
 fn comment_folds(comments: &[Comment], out: &mut Vec<FoldRange>) {
    let mut regions: Vec<usize> = Vec::new();
    let mut run: Option<(usize, usize)> = None;
@@ -32,6 +32,7 @@ pub struct Syntax {
    grammars: Vec<Grammar>,
    /// Language id (and grammar name) -> index into `grammars`.
    by_lang: HashMap<String, usize>,
+    comments: HashMap<String, folding::CommentTokens>,
 }

 pub(crate) struct Grammar {
@@ -107,7 +108,14 @@ impl Syntax {
                }
            }
        }
-        Self { grammars, by_lang }
+        let mut comments = HashMap::new();
+        for cfg in languages {
+            comments.insert(cfg.id.as_str().to_owned(), folding::CommentTokens::from(cfg));
+            if let Some(name) = &cfg.tree_sitter {
+                comments.entry(name.clone()).or_insert_with(|| folding::CommentTokens::from(cfg));
+            }
+        }
+        Self { grammars, by_lang, comments }
    }

    /// Names of the bundled grammars (valid values for `tree-sitter = "..."`).
@@ -161,8 +169,21 @@ impl Syntax {
    }

    pub fn folding(&self, lang: &LanguageId, text: &str) -> Vec<FoldRange> {
-        self.analyze(lang, text, |g, tree, text| Some(folding::folding(g.spec, g.kinds(), tree, text)))
-            .unwrap_or_default()
+        let tokens = self.comment_tokens(lang);
+        self.analyze(lang, text, |g, tree, text| Some(folding::folding(g.spec, g.kinds(), tree, text, tokens)))
+            .unwrap_or_else(|| self.custom_folding(lang, text))
+    }
+
+    fn comment_tokens(&self, lang: &LanguageId) -> &folding::CommentTokens {
+        static EMPTY: OnceLock<folding::CommentTokens> = OnceLock::new();
+        self.comments.get(lang.as_str()).unwrap_or_else(|| EMPTY.get_or_init(Default::default))
+    }
+
+    fn custom_folding(&self, lang: &LanguageId, text: &str) -> Vec<FoldRange> {
+        if text.len() > MAX_PARSE_BYTES {
+            return Vec::new();
+        }
+        folding::custom_folding(text, self.comment_tokens(lang))
    }

    pub fn tags(&self, lang: &LanguageId, text: &str) -> Vec<SymbolTag> {
@@ -969,6 +969,85 @@ fn g() {}
    );
 }

+#[test]
+fn folding_xml_custom_regions() {
+    for (start, end) in [
+        ("<!--region要折叠的内容-->", "<!-- endregion -->"),
+        ("<!--region name-->", "<!--endregion-->"),
+        ("<!-- <editor-fold desc=\"Head\"> -->", "<!-- </editor-fold> -->"),
+    ] {
+        let text = format!("<project>\n  {start}\n  <name>demo</name>\n  {end}\n</project>\n");
+        assert!(folds("xml", &text).contains(&(1, 3, FoldKind::Region)), "{text}");
+    }
+}
+
+#[test]
+fn folding_custom_regions_use_configured_comment_tokens() {
+    let fixture: serde_json::Value =
+        serde_json::from_str(include_str!("../../../../fixtures/folding/regions.json")).unwrap();
+    let registry = LanguageRegistry::load(None).unwrap();
+    let cache = SyntaxCache::new(std::sync::Arc::new(Syntax::new()));
+    for language in fixture["languages"].as_array().unwrap() {
+        let id = language.as_str().unwrap();
+        let cfg = registry.get(&lang(id)).unwrap();
+        let mut tokens = Vec::new();
+        if let Some(line) = &cfg.line_comment {
+            tokens.push((line.as_str(), ""));
+        }
+        if let Some((open, close)) = &cfg.block_comment {
+            tokens.push((open.as_str(), close.as_str()));
+        }
+        for (open, close) in tokens {
+            for space in ["", " ", "  "] {
+                // Word delimiters require a separator in the language itself.
+                if space.is_empty() && open.ends_with(|c: char| c.is_ascii_alphanumeric()) {
+                    continue;
+                }
+                let wrap = |body: &str| format!("  {open}{space}{body}{space}{close}");
+                for marker in fixture["markers"].as_array().unwrap() {
+                    let start = wrap(marker["start"].as_str().unwrap());
+                    let end = wrap(marker["end"].as_str().unwrap());
+                    let tokens = folding::CommentTokens::from(&cfg);
+                    assert_eq!(folding::region_marker(&start, &tokens), Some(true), "{id}: {start}");
+                    assert_eq!(folding::region_marker(&end, &tokens), Some(false), "{id}: {end}");
+                    // Ruby block delimiters must occupy separate lines; Haskell
+                    // interprets `--` followed immediately by a symbol as an operator.
+                    if (id == "ruby" && open == "=begin") || (id == "haskell" && space.is_empty()) {
+                        continue;
+                    }
+                    let text = format!("{start}\n\n{end}\n");
+                    let expected = vec![(0, 2, FoldKind::Region)];
+                    assert_eq!(folds(id, &text), expected, "{id}: {text}");
+                    let doc = ide_core::DocId::next();
+                    cache.open(doc, &lang(id), 0);
+                    let actual = cache.folding(doc, &lang(id), 0, &text);
+                    assert_eq!(cache.folding(doc, &lang(id), 0, &text), actual);
+                    cache.close(doc);
+                    assert_eq!(
+                        actual.iter().map(|f| (f.start_line, f.end_line, f.kind)).collect::<Vec<_>>(),
+                        expected,
+                        "cached {id}: {text}"
+                    );
+                    let nested = format!("{end}\n\n{start}\n{start}\n\n{end}\n{end}\n{start}\n");
+                    assert_eq!(
+                        folds(id, &nested),
+                        vec![(2, 6, FoldKind::Region), (3, 5, FoldKind::Region)],
+                        "nested {id}: {nested}"
+                    );
+                }
+                for invalid in fixture["invalid"].as_array().unwrap() {
+                    let start = wrap(invalid.as_str().unwrap());
+                    assert_eq!(
+                        folding::region_marker(&start, &folding::CommentTokens::from(&cfg)),
+                        None,
+                        "invalid {id}: {start}"
+                    );
+                }
+            }
+        }
+    }
+}
+
 #[test]
 fn folding_python_bodies_start_at_header() {
    let src = "import os\nimport sys\n\nclass A:\n    def f(self):\n        return [\n            1,\n        ]\n\n\ndef g():\n    pass\n";
@@ -7,6 +7,7 @@ license.workspace = true

 [dependencies]
 ide-core.workspace = true
+ide-vfs.workspace = true
 dunce.workspace = true
 ide-text.workspace = true
 ide-language.workspace = true
@@ -189,9 +189,12 @@ impl ClientHandler {
        // Convert before calling the hook: it re-enters document sync.
        let edit = convert::workspace_edit(&mgr.conv(self.encoding()), edit);
        let applied = match mgr.apply_edit_hook() {
-            Some(hook) => hook(edit),
+            Some(hook) => hook(edit.clone()),
            None => false,
        };
+        if applied {
+            let _ = mgr.applied_edits.send((self.server.id, edit));
+        }
        let mut reply = json!({ "applied": applied });
        if !applied {
            reply["failureReason"] = json!("edit could not be applied");
@@ -291,6 +294,21 @@ impl Handler for ClientHandler {
 /// `initializationOptions` with its `settings` merged over them.
 pub(crate) fn all_settings(cfg: &ide_language::LanguageServerConfig) -> Value {
    let mut out = cfg.initialization_options.as_ref().and_then(|v| serde_json::to_value(v).ok()).unwrap_or(Value::Null);
+    if cfg.name == "jdtls" {
+        out = out.get("settings").cloned().unwrap_or_else(|| json!({}));
+        if let Some(settings) = &cfg.settings {
+            // Accept the initialization-options wrapper as well as LSP settings.
+            if let Some(nested) = settings.get("settings") {
+                merge(&mut out, nested.clone());
+            }
+            let mut direct = settings.clone();
+            if let Some(direct) = direct.as_object_mut() {
+                direct.remove("settings");
+            }
+            merge(&mut out, direct);
+        }
+        return out;
+    }
    if let Some(settings) = &cfg.settings {
        merge(&mut out, settings.clone());
    }
@@ -17,6 +17,9 @@ use std::sync::Arc;
 use std::time::{Duration, Instant};

 const SERVER: &str = "jdtls";
+
+mod formatter;
+pub use formatter::configure_formatter;
 /// First start imports the Maven / Gradle model, which can take minutes.
 const READY_TIMEOUT: Duration = Duration::from_secs(240);
 /// A workspace build of a large multi-module project can take far longer than
@@ -35,6 +38,48 @@ const ACCESS_OPTIONS: [&str; 2] = [
    "org.eclipse.jdt.core.compiler.problem.discouragedReference",
 ];

+/// Keep the source model in protocol settings so jdtls's invisible-project
+/// initialization and configuration use the same roots as workspace builds.
+pub fn configure_source_paths(cfg: &mut ide_language::LanguageServerConfig, paths: Option<Vec<String>>) {
+    if cfg.name != SERVER {
+        return;
+    }
+    if let Some(paths) = paths {
+        let mut settings = cfg.settings.take().unwrap_or_else(|| json!({}));
+        settings["java"]["project"]["sourcePaths"] = json!(paths);
+        cfg.settings = Some(settings);
+    }
+}
+
+pub(crate) fn source_paths_removed(
+    current: &ide_language::LanguageServerConfig,
+    next: &ide_language::LanguageServerConfig,
+) -> bool {
+    current.name == SERVER
+        && crate::handler::all_settings(current).pointer("/java/project/sourcePaths").is_some()
+        && crate::handler::all_settings(next).pointer("/java/project/sourcePaths").is_none()
+}
+
+pub(crate) fn source_trigger(root: &Path, paths: &[Value]) -> Option<PathBuf> {
+    for path in paths.iter().filter_map(Value::as_str) {
+        // Runs can start jdtls without an editor. Invisible-project import still
+        // needs a Java trigger file; discovery is bounded and runs off async workers.
+        let found = ignore::WalkBuilder::new(root.join(path))
+            .standard_filters(false)
+            .max_depth(Some(32))
+            .build()
+            .take(4000)
+            .filter_map(Result::ok)
+            .find(|e| {
+                e.file_type().is_some_and(|t| t.is_file()) && e.path().extension().is_some_and(|ext| ext == "java")
+            });
+        if let Some(entry) = found {
+            return Some(entry.into_path());
+        }
+    }
+    None
+}
+
 fn compiler_defaults(cfg: &ide_language::LanguageServerConfig) -> Value {
    // updateSettings persists project options. Only use it when jdtls redirects
    // generated metadata into its workspace, and never touch an existing .settings.
@@ -147,6 +192,24 @@ pub struct JavaCompileError {
    pub message: String,
 }

+/// Holds off JDT writers while an external compiler builds and snapshots launch outputs.
+/// Restores current settings even when preparation fails or is cancelled.
+pub struct JavaExternalBuild {
+    server: Arc<Server>,
+    run: Running,
+    _lock: tokio::sync::OwnedMutexGuard<()>,
+}
+
+impl Drop for JavaExternalBuild {
+    fn drop(&mut self) {
+        self.server.java_autobuild_suspended.store(false, std::sync::atomic::Ordering::SeqCst);
+        let settings = crate::handler::all_settings(&self.server.effective_config());
+        if let Err(e) = self.run.peer.notify("workspace/didChangeConfiguration", json!({ "settings": settings })) {
+            tracing::debug!("jdtls: restoring autobuild: {e}");
+        }
+    }
+}
+
 /// Error diagnostics sorted by file and position, capped at `limit`, and their total.
 pub fn compile_errors(
    diagnostics: Vec<(PathBuf, lsp_types::Diagnostic)>,
@@ -336,7 +399,8 @@ impl LspManager {
        self.jdtls_command_cancellable(path, command, arguments, &CancellationToken::new()).await
    }

-    async fn jdtls_command_cancellable(
+    /// Cancellable delegate commands for project-owned background services.
+    pub async fn jdtls_command_cancellable(
        &self,
        path: &Path,
        command: &str,
@@ -391,9 +455,28 @@ impl LspManager {
            .map_err(|e| crate::rpc_err(&server.name, "java/projectConfigurationsUpdate", e))
    }

+    /// Pause autobuild before resolving the launch classpath. That query takes the
+    /// Java project's workspace scheduling rule, draining the interrupted autobuild.
+    /// Keep this guard until Maven outputs have been copied out of JDT's reach.
+    pub async fn java_external_build(&self, path: &Path, cancel: &CancellationToken) -> IdeResult<JavaExternalBuild> {
+        let (server, run) = self.jdtls(path, cancel).await?;
+        let lock = cancellable_wait(cancel, server.java_build_lock.clone().lock_owned()).await?;
+        server.java_autobuild_suspended.store(true, std::sync::atomic::Ordering::SeqCst);
+        let guard = JavaExternalBuild { server, run, _lock: lock };
+        let settings = crate::handler::all_settings(&guard.server.effective_config());
+        guard
+            .run
+            .peer
+            .notify("workspace/didChangeConfiguration", json!({ "settings": settings }))
+            .map_err(|e| crate::rpc_err(SERVER, "workspace/didChangeConfiguration", e))?;
+        Ok(guard)
+    }
+
    /// Incremental build of the jdtls workspace (`java/buildWorkspace`), so
    /// class files are up to date before a launch.
    pub async fn java_build(&self, path: &Path, cancel: &CancellationToken) -> IdeResult<JavaBuildStatus> {
+        let (server, _) = self.jdtls(path, cancel).await?;
+        let _lock = cancellable_wait(cancel, server.java_build_lock.lock()).await?;
        let mut v = self.jdtls_request(path, "java/buildWorkspace", json!(false), BUILD_TIMEOUT, cancel).await?;
        // The first build can finish the Maven import before ServiceReady is handled.
        let (server, run) = self.jdtls(path, cancel).await?;
@@ -490,6 +573,59 @@ impl LspManager {
        collect()
    }

+    /// Resolve a disk/archive class to project source or the server's binary document.
+    /// Archive URIs must come from JDT's Java model: fabricated handles cannot map debug lines.
+    pub async fn java_class_file(&self, path: &Path, archive: Option<(PathBuf, String)>) -> IdeResult<String> {
+        let cancel = CancellationToken::new();
+        self.jdtls(&self.project_root, &cancel).await?;
+        if let Some((jar, entry)) = archive {
+            let entry = entry
+                .strip_prefix("META-INF/versions/")
+                .and_then(|s| s.split_once('/').map(|(_, s)| s))
+                .unwrap_or(&entry);
+            let class = entry.strip_suffix(".class").ok_or_else(|| IdeError::not_found("expected a class file"))?;
+            let outer = class.split('$').next().unwrap_or(class);
+            let (package, name) = outer.rsplit_once('/').unwrap_or(("", outer));
+            let query = outer.replace('/', ".");
+            let symbols = self.workspace_symbols(&query, cancel).await?;
+            let package = package.replace('/', ".");
+            let name = name.to_owned();
+            let outer = outer.to_owned();
+            return tokio::task::spawn_blocking(move || {
+                symbols
+                    .into_iter()
+                    .filter_map(|s| s.location.uri)
+                    .find(|uri| crate::virtual_doc::matches_class(uri, &jar, &package, &name))
+                    .ok_or_else(|| {
+                        IdeError::not_found(format!("jdtls could not resolve {} in {}", outer, jar.display()))
+                    })
+            })
+            .await
+            .map_err(|e| IdeError::internal(e.to_string()))?;
+        }
+        let uri = crate::uri::path_to_uri_string(path);
+        // classFileContents accepts file URIs, but java-debug's line mapping only accepts JDT handles.
+        let doc = self.virtual_document(&uri).await?;
+        let name = path.file_stem().and_then(|s| s.to_str()).unwrap_or("").split('$').next().unwrap_or("");
+        let package = doc
+            .text
+            .lines()
+            .find_map(|l| l.trim().strip_prefix("package ").and_then(|p| p.strip_suffix(';')))
+            .unwrap_or("");
+        let relative = PathBuf::from(package.replace('.', "/")).join(format!("{name}.java"));
+        let key = "org.eclipse.jdt.ls.core.sourcePaths";
+        let settings = self
+            .jdtls_project_command(path, "java.project.getSettings", vec![json!(uri), json!([key])], &cancel)
+            .await?;
+        let roots: Vec<PathBuf> =
+            settings[key].as_array().into_iter().flatten().filter_map(Value::as_str).map(PathBuf::from).collect();
+        let source =
+            tokio::task::spawn_blocking(move || roots.into_iter().map(|r| r.join(&relative)).find(|p| p.is_file()))
+                .await
+                .map_err(|e| IdeError::internal(e.to_string()))?;
+        Ok(source.map(|s| s.to_string_lossy().into_owned()).unwrap_or(uri))
+    }
+
    /// Starts (or reuses) java-debug's DAP server inside jdtls and returns its port.
    pub async fn java_debug_server(&self, path: &Path) -> IdeResult<u16> {
        let v = self.jdtls_command(path, "vscode.java.startDebugSession", Vec::new()).await.map_err(|e| {
@@ -500,7 +636,7 @@ impl LspManager {
            }
        })?;
        // Hot code replace after each (auto-)build; errors only cost the feature.
-        let settings = json!({ "hotCodeReplace": "auto", "showStaticVariables": false, "showQualifiedNames": false,
+        let settings = json!({ "debugSupportOnDecompiledSource": "on", "hotCodeReplace": "auto", "showStaticVariables": false, "showQualifiedNames": false,
            "showLogicalStructure": true, "showToString": true, "maxStringLength": 0,
            // java-debug NPEs on a missing level (java.util.logging names).
            "logLevel": "WARNING" });
@@ -518,6 +654,65 @@ impl LspManager {
 mod tests {
    use super::*;

+    fn java_config() -> ide_language::LanguageServerConfig {
+        let language: ide_language::LanguageConfig =
+            toml::from_str(include_str!("../../../languages/java.toml")).unwrap();
+        language.language_servers.into_iter().next().unwrap()
+    }
+
+    #[test]
+    fn source_settings_preserve_java_defaults_and_library_resolution() {
+        let mut cfg = java_config();
+        configure_source_paths(&mut cfg, Some(vec!["src/main/java".into(), "tests".into()]));
+        let settings = crate::handler::all_settings(&cfg);
+        assert_eq!(settings["java"]["project"]["sourcePaths"], json!(["src/main/java", "tests"]));
+        assert_eq!(settings["java"]["project"]["referencedLibraries"], json!(["lib/**/*.jar"]));
+        assert_eq!(settings["java"]["autobuild"]["enabled"], true);
+        assert_eq!(settings["java"]["contentProvider"]["preferred"], "fernflowerContentProvider");
+        assert!(settings.get("bundles").is_none());
+        assert!(settings.get("settings").is_none(), "didChangeConfiguration takes java settings directly");
+    }
+
+    #[test]
+    fn unmarked_and_managed_source_models_are_not_overridden() {
+        let mut cfg = java_config();
+        let initial = cfg.clone();
+        configure_source_paths(&mut cfg, None);
+        assert_eq!(cfg, initial);
+        assert!(crate::handler::all_settings(&cfg).pointer("/java/project/sourcePaths").is_none());
+        configure_source_paths(&mut cfg, Some(vec!["custom".into()]));
+        assert!(source_paths_removed(&cfg, &initial));
+        assert!(!source_paths_removed(&initial, &cfg));
+        let mut other = initial;
+        other.name = "other".into();
+        let initial = other.clone();
+        configure_source_paths(&mut other, Some(vec!["custom".into()]));
+        assert_eq!(other, initial);
+    }
+
+    #[test]
+    fn explicit_java_protocol_settings_override_defaults_in_either_shape() {
+        for wrapped in [false, true] {
+            let mut cfg = java_config();
+            let settings = json!({"java": {"project": {"referencedLibraries": ["vendor/*.jar"]}}});
+            cfg.settings = Some(if wrapped { json!({"settings": settings}) } else { settings });
+            configure_source_paths(&mut cfg, Some(vec!["custom".into()]));
+            let settings = crate::handler::all_settings(&cfg);
+            assert_eq!(settings["java"]["project"]["referencedLibraries"], json!(["vendor/*.jar"]));
+            assert_eq!(settings["java"]["project"]["sourcePaths"], json!(["custom"]));
+        }
+    }
+
+    #[test]
+    fn run_without_an_editor_discovers_a_trigger_inside_its_source_roots() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::create_dir_all(dir.path().join("src/demo/engine")).unwrap();
+        let file = dir.path().join("src/demo/engine/Main.java");
+        std::fs::write(&file, "package demo.engine; public class Main {}").unwrap();
+        assert_eq!(source_trigger(dir.path(), &[json!("generated"), json!("src")]), Some(file));
+        assert_eq!(source_trigger(dir.path(), &[json!("tests")]), None);
+    }
+
    #[tokio::test]
    async fn cancellation_ends_a_pending_wait() {
        let cancel = CancellationToken::new();
@@ -0,0 +1,224 @@
+use ide_core::IdeResult;
+use ide_core::editor_settings::LanguageCodeStyle;
+use ide_core::settings::LanguageServerSettings;
+use ide_language::LanguageServerConfig;
+use serde_json::json;
+use std::path::Path;
+
+const PROFILE: &str = "OpenIDEA IntelliJ IDEA";
+const XML: &str = include_str!("intellij.xml");
+
+/// Protocol settings only: switching profiles reaches a running jdtls through
+/// didChangeConfiguration. Explicit language-server settings are applied later.
+pub fn configure_formatter(
+    cfg: &mut LanguageServerConfig,
+    style: Option<&LanguageCodeStyle>,
+    project_root: &Path,
+    data_dir: &Path,
+    overrides: Option<&LanguageServerSettings>,
+) -> IdeResult<()> {
+    if cfg.name != "jdtls" {
+        return Ok(());
+    }
+    // jdtls retains omitted preferences. Send empty values when returning to
+    // Default, while preserving any profile from the base server configuration.
+    let inherited = crate::handler::all_settings(cfg);
+    let defaults = json!({
+        "url": inherited.pointer("/java/format/settings/url").cloned().unwrap_or(json!("")),
+        "profile": inherited.pointer("/java/format/settings/profile").cloned().unwrap_or(json!("")),
+    });
+    let mut settings = cfg.settings.take().unwrap_or_else(|| json!({}));
+    settings["java"]["format"]["settings"] = formatter_overrides(defaults, overrides);
+    cfg.settings = Some(settings);
+    let Some(style) = style else { return Ok(()) };
+    let (path, profile) = match style.formatter.as_deref() {
+        Some("intellij") => {
+            let path = data_dir.join("lsp/jdtls/intellij.xml");
+            std::fs::create_dir_all(path.parent().unwrap())?;
+            if std::fs::read_to_string(&path).ok().as_deref() != Some(XML) {
+                ide_vfs::write_atomic(&path, XML.as_bytes())?;
+            }
+            (path, PROFILE)
+        }
+        Some("custom") => {
+            let value = style.formatter_path.as_deref().unwrap_or_default().trim();
+            if value.is_empty() {
+                return Err(ide_core::IdeError::invalid("Choose an Eclipse formatter XML file."));
+            }
+            let path = project_root.join(value);
+            // Fail without poisoning the server launch; code intelligence remains available.
+            std::fs::File::open(&path).map_err(|error| {
+                let path = path.display();
+                ide_core::IdeError::invalid(format!("Cannot read Java formatter XML {path}: {error}"))
+            })?;
+            if !path.is_file() {
+                return Err(ide_core::IdeError::invalid(format!("Not a formatter XML file: {}", path.display())));
+            }
+            (path, "")
+        }
+        _ => return Ok(()),
+    };
+    let mut settings = cfg.settings.take().unwrap_or_else(|| json!({}));
+    settings["java"]["format"]["settings"] = formatter_overrides(
+        json!({
+            "url": crate::uri::path_to_uri_string(&path),
+            "profile": profile,
+        }),
+        overrides,
+    );
+    cfg.settings = Some(settings);
+    Ok(())
+}
+
+fn formatter_overrides(mut format: serde_json::Value, overrides: Option<&LanguageServerSettings>) -> serde_json::Value {
+    if let Some(overrides) = overrides {
+        // all_settings merges protocol settings over initializationOptions.
+        // Mirror explicit formatter keys so generated protocol values cannot
+        // accidentally mask an advanced initializationOptions override.
+        for layer in [
+            overrides.initialization_options.as_ref().and_then(|v| v.pointer("/settings/java/format/settings")),
+            overrides.settings.as_ref().and_then(|v| v.pointer("/settings/java/format/settings")),
+            overrides.settings.as_ref().and_then(|v| v.pointer("/java/format/settings")),
+        ]
+        .into_iter()
+        .flatten()
+        {
+            for key in ["url", "profile"] {
+                if let Some(value) = layer.get(key) {
+                    format[key] = value.clone();
+                }
+            }
+        }
+    }
+    format
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn config(name: &str) -> LanguageServerConfig {
+        serde_json::from_value(json!({"name": name, "command": name})).unwrap()
+    }
+
+    #[test]
+    fn profiles_resolve_paths_preserve_settings_and_leave_other_servers_alone() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path().join("project with 空格");
+        let data = dir.path().join("data");
+        std::fs::create_dir_all(&root).unwrap();
+        let custom = root.join("style.xml");
+        std::fs::write(&custom, XML).unwrap();
+        for name in ["jdtls", "rust-analyzer"] {
+            for mode in ["default", "intellij", "custom", "unknown"] {
+                let mut cfg = LanguageServerConfig {
+                    name: name.into(),
+                    settings: Some(json!({"java": {"autobuild": {"enabled": false}}})),
+                    ..config(name)
+                };
+                let initial = cfg.clone();
+                let style = LanguageCodeStyle {
+                    formatter: Some(mode.into()),
+                    formatter_path: Some("style.xml".into()),
+                    ..Default::default()
+                };
+                configure_formatter(&mut cfg, Some(&style), &root, &data, None).unwrap();
+                if name != "jdtls" {
+                    assert_eq!(cfg, initial);
+                    continue;
+                }
+                let settings = crate::handler::all_settings(&cfg);
+                if !["intellij", "custom"].contains(&mode) {
+                    assert_eq!(settings["java"]["format"]["settings"], json!({"url": "", "profile": ""}));
+                    continue;
+                }
+                let path = if mode == "custom" { custom.clone() } else { data.join("lsp/jdtls/intellij.xml") };
+                assert_eq!(settings["java"]["format"]["settings"]["url"], crate::uri::path_to_uri_string(&path));
+                assert_eq!(
+                    settings["java"]["format"]["settings"]["profile"],
+                    if mode == "custom" { "" } else { PROFILE }
+                );
+                assert_eq!(settings["java"]["autobuild"]["enabled"], false);
+                assert_eq!(std::fs::read_to_string(path).unwrap(), XML);
+            }
+        }
+    }
+
+    #[test]
+    fn unavailable_custom_paths_are_nonfatal_and_do_not_set_launch_error() {
+        let dir = tempfile::tempdir().unwrap();
+        for path in ["", "missing.xml", "."] {
+            let mut cfg = config("jdtls");
+            let style = LanguageCodeStyle {
+                formatter: Some("custom".into()),
+                formatter_path: Some(path.into()),
+                ..Default::default()
+            };
+            assert!(configure_formatter(&mut cfg, Some(&style), dir.path(), dir.path(), None).is_err());
+            assert!(cfg.launch_error.is_none());
+            assert_eq!(crate::handler::all_settings(&cfg)["java"]["format"]["settings"]["url"], "");
+        }
+    }
+
+    #[test]
+    fn default_keeps_explicit_server_configuration_and_custom_accepts_absolute_paths() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("custom.xml");
+        std::fs::write(&path, XML).unwrap();
+        let mut cfg = config("jdtls");
+        cfg.initialization_options = Some(
+            toml::Value::try_from(json!({
+                "settings": {"java": {"format": {"settings": {"url": "existing.xml", "profile": "Existing"}}}}
+            }))
+            .unwrap(),
+        );
+        configure_formatter(&mut cfg, None, dir.path(), dir.path(), None).unwrap();
+        assert_eq!(
+            crate::handler::all_settings(&cfg)["java"]["format"]["settings"],
+            json!({"url": "existing.xml", "profile": "Existing"})
+        );
+        let style = LanguageCodeStyle {
+            formatter: Some("custom".into()),
+            formatter_path: Some(path.to_string_lossy().into_owned()),
+            ..Default::default()
+        };
+        configure_formatter(&mut cfg, Some(&style), &dir.path().join("different-root"), dir.path(), None).unwrap();
+        assert_eq!(
+            crate::handler::all_settings(&cfg)["java"]["format"]["settings"]["url"],
+            crate::uri::path_to_uri_string(&path)
+        );
+    }
+    #[test]
+    fn advanced_formatter_options_win_for_each_profile_and_protocol_layer() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::write(dir.path().join("custom.xml"), XML).unwrap();
+        for mode in ["default", "intellij", "custom"] {
+            for layer in ["initialization", "wrapped", "direct"] {
+                let mut overrides = LanguageServerSettings {
+                    initialization_options: Some(json!({"settings": {"java": {"format": {"settings": {
+                        "url": "advanced.xml", "profile": "Advanced"
+                    }}}}})),
+                    ..Default::default()
+                };
+                if layer != "initialization" {
+                    let value = json!({"java": {"format": {"settings": {"profile": "Protocol"}}}});
+                    overrides.settings = Some(if layer == "wrapped" { json!({"settings": value}) } else { value });
+                }
+                let mut cfg = config("jdtls");
+                let style = LanguageCodeStyle {
+                    formatter: Some(mode.into()),
+                    formatter_path: Some("custom.xml".into()),
+                    ..Default::default()
+                };
+                configure_formatter(&mut cfg, Some(&style), dir.path(), dir.path(), Some(&overrides)).unwrap();
+                assert_eq!(
+                    crate::handler::all_settings(&cfg)["java"]["format"]["settings"],
+                    json!({
+                        "url": "advanced.xml",
+                        "profile": if layer == "initialization" { "Advanced" } else { "Protocol" },
+                    })
+                );
+            }
+        }
+    }
+}
@@ -0,0 +1,235 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  IntelliJ IDEA Java defaults, approximated using Eclipse JDT formatter options.
+  Source revision: JetBrains/intellij-community 8fe3709d185cd13053d17b76d9690aef674d4268
+  platform/code-style-api/src/com/intellij/psi/codeStyle/CommonCodeStyleSettings.java
+  platform/code-style-api/src/com/intellij/psi/codeStyle/CodeStyleSettings.java
+  platform/code-style-api/src/com/intellij/psi/codeStyle/CodeStyleDefaults.java
+  java/java-frontback-impl/src/com/intellij/psi/codeStyle/JavaCodeStyleSettings.java
+  JavaLanguageCodeStyleSettingsProvider.customizeDefaults does not override these values.
+  https://www.jetbrains.com/help/idea/code-style-java.html describes the corresponding controls.
+  Each option below names its IDEA setting; JDT has no exact equivalent for every rule.
+  A formatter profile does not sort/group imports (Organize Imports is a separate action).
+  Preserve IDEA KEEP_LINE_BREAKS=true using Wrap where necessary (WRAP_COMPACT) and
+  join_wrapped_lines=false (Never join already wrapped lines). JDT NO_SPLIT joins some
+  manual parameter/call/chain breaks even when joining is disabled. Preserving manual
+  breaks takes priority: wrappable code exceeding 120 columns will also wrap, a known
+  difference from IDEA defaults (DO_NOT_WRAP / WRAP_LONG_LINES=false).
+  Alignment values: 16 = WRAP_COMPACT + INDENT_DEFAULT; 18 = WRAP_COMPACT + INDENT_ON_COLUMN.
+  The comment width 999999 approximates WRAP_COMMENTS=false without JDT integer overflow.
+  JDT has a shared blank-line preservation limit and different empty-body/Javadoc handling.
+-->
+<profiles version="23">
+  <profile kind="CodeFormatterProfile" name="OpenIDEA IntelliJ IDEA" version="23">
+    <!-- IndentOptions.USE_TAB_CHARACTER = false -->
+    <setting id="org.eclipse.jdt.core.formatter.tabulation.char" value="space"/>
+    <!-- IndentOptions.TAB_SIZE = 4 -->
+    <setting id="org.eclipse.jdt.core.formatter.tabulation.size" value="4"/>
+    <!-- IndentOptions.INDENT_SIZE = 4 -->
+    <setting id="org.eclipse.jdt.core.formatter.indentation.size" value="4"/>
+    <!-- IndentOptions.CONTINUATION_INDENT_SIZE = 8 (two 4-space units) -->
+    <setting id="org.eclipse.jdt.core.formatter.continuation_indentation" value="2"/>
+    <!-- IndentOptions.CONTINUATION_INDENT_SIZE = 8 -->
+    <setting id="org.eclipse.jdt.core.formatter.continuation_indentation_for_array_initializer" value="2"/>
+    <!-- CodeStyleSettings.RIGHT_MARGIN = 120; wrap where necessary to preserve manual line breaks (see known difference above) -->
+    <setting id="org.eclipse.jdt.core.formatter.lineSplit" value="120"/>
+    <!-- KEEP_LINE_BREAKS = true; Never join already wrapped lines -->
+    <setting id="org.eclipse.jdt.core.formatter.join_wrapped_lines" value="false"/>
+    <!-- KEEP_BLANK_LINES_IN_DECLARATIONS / IN_CODE / BEFORE_RBRACE = 2 (JDT has one shared limit) -->
+    <setting id="org.eclipse.jdt.core.formatter.number_of_empty_lines_to_preserve" value="2"/>
+    <!-- METHOD_PARAMETERS_WRAP = DO_NOT_WRAP; ALIGN_MULTILINE_PARAMETERS = true (indent on column); JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_parameters_in_method_declaration" value="18"/>
+    <!-- METHOD_PARAMETERS_WRAP = DO_NOT_WRAP; ALIGN_MULTILINE_PARAMETERS = true (indent on column); JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_parameters_in_constructor_declaration" value="18"/>
+    <!-- CALL_PARAMETERS_WRAP / ANNOTATION_PARAMETER_WRAP = DO_NOT_WRAP; ALIGN_MULTILINE_PARAMETERS_IN_CALLS = false; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_arguments_in_method_invocation" value="16"/>
+    <!-- CALL_PARAMETERS_WRAP / ANNOTATION_PARAMETER_WRAP = DO_NOT_WRAP; ALIGN_MULTILINE_PARAMETERS_IN_CALLS = false; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_arguments_in_allocation_expression" value="16"/>
+    <!-- CALL_PARAMETERS_WRAP / ANNOTATION_PARAMETER_WRAP = DO_NOT_WRAP; ALIGN_MULTILINE_PARAMETERS_IN_CALLS = false; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_arguments_in_explicit_constructor_call" value="16"/>
+    <!-- CALL_PARAMETERS_WRAP / ANNOTATION_PARAMETER_WRAP = DO_NOT_WRAP; ALIGN_MULTILINE_PARAMETERS_IN_CALLS = false; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_arguments_in_enum_constant" value="16"/>
+    <!-- CALL_PARAMETERS_WRAP / ANNOTATION_PARAMETER_WRAP = DO_NOT_WRAP; ALIGN_MULTILINE_PARAMETERS_IN_CALLS = false; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_arguments_in_annotation" value="16"/>
+    <!-- METHOD_CALL_CHAIN_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_selector_in_method_invocation" value="16"/>
+    <!-- ARRAY_INITIALIZER_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_expressions_in_array_initializer" value="16"/>
+    <!-- ASSIGNMENT_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_assignment" value="16"/>
+    <!-- TERNARY_OPERATION_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_conditional_expression" value="16"/>
+    <!-- EXTENDS_LIST_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_superclass_in_type_declaration" value="16"/>
+    <!-- EXTENDS_LIST_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_superinterfaces_in_type_declaration" value="16"/>
+    <!-- THROWS_LIST_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_throws_clause_in_method_declaration" value="16"/>
+    <!-- THROWS_LIST_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_throws_clause_in_constructor_declaration" value="16"/>
+    <!-- RESOURCE_LIST_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_resources_in_try" value="16"/>
+    <!-- BINARY_OPERATION_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_multiplicative_operator" value="16"/>
+    <!-- BINARY_OPERATION_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_additive_operator" value="16"/>
+    <!-- BINARY_OPERATION_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_string_concatenation" value="16"/>
+    <!-- BINARY_OPERATION_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_shift_operator" value="16"/>
+    <!-- BINARY_OPERATION_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_relational_operator" value="16"/>
+    <!-- BINARY_OPERATION_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_bitwise_operator" value="16"/>
+    <!-- BINARY_OPERATION_WRAP = DO_NOT_WRAP; JDT wrap where necessary preserves manual breaks -->
+    <setting id="org.eclipse.jdt.core.formatter.alignment_for_logical_operator" value="16"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_type_declaration" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_method_declaration" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_constructor_declaration" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_block" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_block_in_case" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_switch" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_anonymous_type_declaration" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_enum_declaration" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_enum_constant" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_annotation_type_declaration" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_lambda_body" value="end_of_line"/>
+    <!-- CLASS_BRACE_STYLE / METHOD_BRACE_STYLE / LAMBDA_BRACE_STYLE / BRACE_STYLE = END_OF_LINE; ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.brace_position_for_array_initializer" value="end_of_line"/>
+    <!-- ELSE_ON_NEW_LINE / CATCH_ON_NEW_LINE / FINALLY_ON_NEW_LINE / WHILE_ON_NEW_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_before_else_in_if_statement" value="do not insert"/>
+    <!-- ELSE_ON_NEW_LINE / CATCH_ON_NEW_LINE / FINALLY_ON_NEW_LINE / WHILE_ON_NEW_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_before_catch_in_try_statement" value="do not insert"/>
+    <!-- ELSE_ON_NEW_LINE / CATCH_ON_NEW_LINE / FINALLY_ON_NEW_LINE / WHILE_ON_NEW_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_before_finally_in_try_statement" value="do not insert"/>
+    <!-- ELSE_ON_NEW_LINE / CATCH_ON_NEW_LINE / FINALLY_ON_NEW_LINE / WHILE_ON_NEW_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_before_while_in_do_statement" value="do not insert"/>
+    <!-- CLASS / METHOD / FIELD_ANNOTATION_WRAP = WRAP_ALWAYS; DO_NOT_WRAP_AFTER_SINGLE_ANNOTATION = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_after_annotation_on_type" value="insert"/>
+    <!-- CLASS / METHOD / FIELD_ANNOTATION_WRAP = WRAP_ALWAYS; DO_NOT_WRAP_AFTER_SINGLE_ANNOTATION = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_after_annotation_on_method" value="insert"/>
+    <!-- CLASS / METHOD / FIELD_ANNOTATION_WRAP = WRAP_ALWAYS; DO_NOT_WRAP_AFTER_SINGLE_ANNOTATION = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_after_annotation_on_field" value="insert"/>
+    <!-- PARAMETER / VARIABLE / ENUM_FIELD_ANNOTATION_WRAP = DO_NOT_WRAP -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_after_annotation_on_parameter" value="do not insert"/>
+    <!-- PARAMETER / VARIABLE / ENUM_FIELD_ANNOTATION_WRAP = DO_NOT_WRAP -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_after_annotation_on_local_variable" value="do not insert"/>
+    <!-- PARAMETER / VARIABLE / ENUM_FIELD_ANNOTATION_WRAP = DO_NOT_WRAP -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_after_annotation_on_enum_constant" value="do not insert"/>
+    <!-- BLANK_LINES_BEFORE_PACKAGE = 0 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_before_package" value="0"/>
+    <!-- BLANK_LINES_AFTER_PACKAGE = 1 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_after_package" value="1"/>
+    <!-- BLANK_LINES_BEFORE_IMPORTS = 1 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_before_imports" value="1"/>
+    <!-- BLANK_LINES_AFTER_IMPORTS = 1 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_after_imports" value="1"/>
+    <!-- BLANK_LINES_AROUND_FIELD / BLANK_LINES_AROUND_FIELD_IN_INTERFACE = 0 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_before_field" value="0"/>
+    <!-- BLANK_LINES_AROUND_METHOD = 1 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_before_method" value="1"/>
+    <!-- BLANK_LINES_AROUND_METHOD_IN_INTERFACE = 1 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_before_abstract_method" value="1"/>
+    <!-- BLANK_LINES_AROUND_CLASS = 1 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_before_member_type" value="1"/>
+    <!-- BLANK_LINES_AFTER_CLASS_HEADER = 0 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_before_first_class_body_declaration" value="0"/>
+    <!-- BLANK_LINES_BEFORE_CLASS_END = 0 (minimum) -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_after_last_class_body_declaration" value="0"/>
+    <!-- BLANK_LINES_AROUND_METHOD / AROUND_CLASS = 1; JDT chunks separate member kinds, not consecutive fields -->
+    <setting id="org.eclipse.jdt.core.formatter.blank_lines_before_new_chunk" value="1"/>
+    <!-- DO_NOT_INDENT_TOP_LEVEL_CLASS_MEMBERS = false -->
+    <setting id="org.eclipse.jdt.core.formatter.indent_body_declarations_compare_to_type_header" value="true"/>
+    <!-- DO_NOT_INDENT_TOP_LEVEL_CLASS_MEMBERS = false -->
+    <setting id="org.eclipse.jdt.core.formatter.indent_body_declarations_compare_to_enum_declaration_header" value="true"/>
+    <!-- DO_NOT_INDENT_TOP_LEVEL_CLASS_MEMBERS = false -->
+    <setting id="org.eclipse.jdt.core.formatter.indent_body_declarations_compare_to_enum_constant_header" value="true"/>
+    <!-- DO_NOT_INDENT_TOP_LEVEL_CLASS_MEMBERS = false -->
+    <setting id="org.eclipse.jdt.core.formatter.indent_body_declarations_compare_to_annotation_declaration_header" value="true"/>
+    <!-- INDENT_CASE_FROM_SWITCH = true -->
+    <setting id="org.eclipse.jdt.core.formatter.indent_switchstatements_compare_to_switch" value="true"/>
+    <!-- INDENT_BREAK_FROM_CASE = true -->
+    <setting id="org.eclipse.jdt.core.formatter.indent_switchstatements_compare_to_cases" value="true"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_code_block_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_method_body_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_lambda_body_block_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_type_declaration_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_anonymous_type_declaration_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_enum_declaration_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_annotation_declaration_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_if_then_body_block_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / LAMBDAS / CLASSES_IN_ONE_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_loop_body_block_on_one_line" value="one_line_never"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / CLASSES_IN_ONE_LINE = false; empty-block handling may differ in JDT -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_in_empty_type_declaration" value="insert"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / CLASSES_IN_ONE_LINE = false; empty-block handling may differ in JDT -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_in_empty_method_body" value="insert"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / CLASSES_IN_ONE_LINE = false; empty-block handling may differ in JDT -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_in_empty_block" value="insert"/>
+    <!-- KEEP_SIMPLE_BLOCKS / METHODS / CLASSES_IN_ONE_LINE = false; empty-block handling may differ in JDT -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_in_empty_anonymous_type_declaration" value="insert"/>
+    <!-- ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE / RBRACE_ON_NEXT_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_empty_array_initializer_on_one_line" value="true"/>
+    <!-- ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE = false; KEEP_LINE_BREAKS = true -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_after_opening_brace_in_array_initializer" value="do not insert"/>
+    <!-- ARRAY_INITIALIZER_RBRACE_ON_NEXT_LINE = false; KEEP_LINE_BREAKS = true -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_new_line_before_closing_brace_in_array_initializer" value="do not insert"/>
+    <!-- SPACE_BEFORE_ARRAY_INITIALIZER_LBRACE / SPACE_WITHIN_ARRAY_INITIALIZER_BRACES / SPACE_WITHIN_EMPTY_ARRAY_INITIALIZER_BRACES = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_array_initializer" value="do not insert"/>
+    <!-- SPACE_BEFORE_ARRAY_INITIALIZER_LBRACE / SPACE_WITHIN_ARRAY_INITIALIZER_BRACES / SPACE_WITHIN_EMPTY_ARRAY_INITIALIZER_BRACES = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_space_after_opening_brace_in_array_initializer" value="do not insert"/>
+    <!-- SPACE_BEFORE_ARRAY_INITIALIZER_LBRACE / SPACE_WITHIN_ARRAY_INITIALIZER_BRACES / SPACE_WITHIN_EMPTY_ARRAY_INITIALIZER_BRACES = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_space_before_closing_brace_in_array_initializer" value="do not insert"/>
+    <!-- SPACE_BEFORE_ARRAY_INITIALIZER_LBRACE / SPACE_WITHIN_ARRAY_INITIALIZER_BRACES / SPACE_WITHIN_EMPTY_ARRAY_INITIALIZER_BRACES = false -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_space_between_empty_braces_in_array_initializer" value="do not insert"/>
+    <!-- SPACE_AROUND_LAMBDA_ARROW = true -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_space_before_lambda_arrow" value="insert"/>
+    <!-- SPACE_AROUND_LAMBDA_ARROW = true -->
+    <setting id="org.eclipse.jdt.core.formatter.insert_space_after_lambda_arrow" value="insert"/>
+    <!-- WRAP_COMMENTS = false; KEEP_FIRST_COLUMN_COMMENT = true (JDT comment formatting disabled to preserve text) -->
+    <setting id="org.eclipse.jdt.core.formatter.comment.format_line_comments" value="false"/>
+    <!-- WRAP_COMMENTS = false (JDT comment formatting disabled to preserve text) -->
+    <setting id="org.eclipse.jdt.core.formatter.comment.format_block_comments" value="false"/>
+    <!-- JavaCodeStyleSettings.ENABLE_JAVADOC_FORMATTING = true -->
+    <setting id="org.eclipse.jdt.core.formatter.comment.format_javadoc_comments" value="true"/>
+    <!-- WRAP_COMMENTS = false; JDT has a separate comment width, so disable its width-based wrapping -->
+    <setting id="org.eclipse.jdt.core.formatter.comment.line_length" value="999999"/>
+    <!-- JavaCodeStyleSettings.JD_INDENT_ON_CONTINUATION = false -->
+    <setting id="org.eclipse.jdt.core.formatter.comment.indent_parameter_description" value="false"/>
+    <!-- JavaCodeStyleSettings.JD_PARAM_DESCRIPTION_ON_NEW_LINE = false -->
+    <setting id="org.eclipse.jdt.core.formatter.comment.insert_new_line_for_parameter" value="false"/>
+    <!-- CodeStyleSettings.FORMATTER_TAGS_ENABLED = true -->
+    <setting id="org.eclipse.jdt.core.formatter.use_on_off_tags" value="true"/>
+    <!-- KEEP_CONTROL_STATEMENT_IN_ONE_LINE = true -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_then_statement_on_same_line" value="true"/>
+    <!-- KEEP_CONTROL_STATEMENT_IN_ONE_LINE = true -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_else_statement_on_same_line" value="true"/>
+    <!-- KEEP_CONTROL_STATEMENT_IN_ONE_LINE = true -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_imple_if_on_one_line" value="true"/>
+    <!-- KEEP_CONTROL_STATEMENT_IN_ONE_LINE = true -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_simple_for_body_on_same_line" value="true"/>
+    <!-- KEEP_CONTROL_STATEMENT_IN_ONE_LINE = true -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_simple_while_body_on_same_line" value="true"/>
+    <!-- KEEP_CONTROL_STATEMENT_IN_ONE_LINE = true -->
+    <setting id="org.eclipse.jdt.core.formatter.keep_simple_do_while_body_on_same_line" value="true"/>
+  </profile>
+</profiles>
@@ -129,6 +129,7 @@ impl Target {
 }

 struct DocSnap {
+    version: i32,
    path: PathBuf,
    uri: lsp::Uri,
    language: LanguageId,
@@ -168,6 +169,7 @@ pub struct LspManager {
    servers: Mutex<Vec<Arc<Server>>>,
    docs: Mutex<HashMap<DocId, DocState>>,
    apply_edit_hook: RwLock<Option<ApplyEditHook>>,
+    applied_edits: tokio::sync::broadcast::Sender<(ide_core::ServerId, WorkspaceEdit)>,
    config_hook: RwLock<Option<ConfigHook>>,
    prepare_hook: RwLock<Option<Arc<PrepareFn>>>,
    servers_hook: RwLock<Option<Arc<ServersFn>>>,
@@ -175,6 +177,7 @@ pub struct LspManager {
    excludes_hook: RwLock<Option<Arc<external_project::ExcludesFn>>>,
    shutting_down: AtomicBool,
    execution_allowed: AtomicBool,
+    java_usages_warned: AtomicBool,
    /// `window/showMessage` texts already surfaced; servers repeat them on every restart/reconfigure.
    shown_messages: Mutex<HashSet<(String, String)>>,
    /// Virtual (non-`file:`) URIs a server returned, by the server that owns them.
@@ -300,6 +303,7 @@ impl LspManager {
            servers: Mutex::new(Vec::new()),
            docs: Mutex::new(HashMap::new()),
            apply_edit_hook: RwLock::new(None),
+            applied_edits: tokio::sync::broadcast::channel(64).0,
            config_hook: RwLock::new(None),
            prepare_hook: RwLock::new(None),
            servers_hook: RwLock::new(None),
@@ -307,6 +311,7 @@ impl LspManager {
            excludes_hook: RwLock::new(None),
            shutting_down: AtomicBool::new(false),
            execution_allowed: AtomicBool::new(true),
+            java_usages_warned: AtomicBool::new(false),
            shown_messages: Mutex::new(HashSet::new()),
            virtual_origins: Mutex::new(HashMap::new()),
            virtual_docs: Mutex::new(HashMap::new()),
@@ -513,7 +518,19 @@ impl LspManager {
            }
        };

-        let init = self.initialize_params(&server);
+        let mut init = self.initialize_params(&server);
+        if server.name == "jdtls"
+            && init["initializationOptions"].get("triggerFiles").is_none()
+            && let Some(paths) = init
+                .pointer("/initializationOptions/settings/java/project/sourcePaths")
+                .and_then(Value::as_array)
+                .cloned()
+        {
+            let root = server.root.clone();
+            if let Ok(Some(path)) = tokio::task::spawn_blocking(move || jdtls::source_trigger(&root, &paths)).await {
+                init["initializationOptions"]["triggerFiles"] = json!([uri::path_to_uri_string(&path)]);
+            }
+        }
        let result = tokio::time::timeout(INITIALIZE_TIMEOUT, peer.request::<_, Value>("initialize", init, None))
            .await
            .unwrap_or(Err(RpcError::Timeout));
@@ -656,12 +673,26 @@ impl LspManager {
    fn initialize_params(&self, server: &Server) -> Value {
        let root_uri = uri::path_to_uri(&server.root);
        let name = server.root.file_name().map(|n| n.to_string_lossy().into_owned()).unwrap_or_else(|| "root".into());
-        let init_options = server
-            .effective_config()
-            .initialization_options
-            .as_ref()
-            .and_then(|v| serde_json::to_value(v).ok())
-            .unwrap_or(Value::Null);
+        let cfg = server.effective_config();
+        let mut init_options =
+            cfg.initialization_options.as_ref().and_then(|v| serde_json::to_value(v).ok()).unwrap_or(Value::Null);
+        if server.name == "jdtls" {
+            if !init_options.is_object() {
+                init_options = json!({});
+            }
+            init_options["settings"] = handler::all_settings(&cfg);
+            let triggers: Vec<_> = self
+                .docs
+                .lock()
+                .values()
+                .filter(|d| d.language.as_str() == "java" && d.path.starts_with(&server.root))
+                .map(|d| uri::path_to_uri_string(&d.path))
+                .collect();
+            if !triggers.is_empty() && init_options.get("triggerFiles").is_none() {
+                // Re-import cached invisible projects with the current source model.
+                init_options["triggerFiles"] = json!(triggers);
+            }
+        }
        let mut params = json!({
            "processId": std::process::id(),
            "clientInfo": { "name": "OpenIDEA", "version": env!("CARGO_PKG_VERSION") },
@@ -672,6 +703,9 @@ impl LspManager {
            "capabilities": caps::client_capabilities(),
            "trace": "off",
        });
+        if server.name == "gopls" {
+            params["capabilities"]["experimental"]["interactiveResolve"] = json!({ "inputTypes": ["string"] });
+        }
        if !init_options.is_null() {
            params["initializationOptions"] = init_options;
        }
@@ -888,6 +922,7 @@ impl LspManager {
        let docs = self.docs.lock();
        let d = docs.get(&doc).ok_or_else(|| IdeError::not_found(format!("{doc} is not open")))?;
        Ok(DocSnap {
+            version: d.version,
            path: d.path.clone(),
            uri: d.uri.clone(),
            language: d.language.clone(),
@@ -1156,6 +1191,106 @@ impl LspManager {
        cancel: CancellationToken,
    ) -> IdeResult<References> {
        let (snap, targets) = self.doc_targets(doc, "find references", |c| c.has("referencesProvider")).await?;
+        // The extension preserves method identity before JDT collapses references to locations.
+        // Old/custom servers retain the standard protocol, including cancellation and scope widening.
+        if targets.len() == 1
+            && targets[0].server.name == "jdtls"
+            && targets[0].caps().commands().iter().any(|c| c == "openidea.java.usages")
+        {
+            let classified = async {
+                let t = &targets[0];
+                let extension_error = Mutex::new(None);
+                let query = || async {
+                    if cancel.is_cancelled() || !self.docs.lock().get(&doc).is_some_and(|d| d.version == snap.version) {
+                        return Err(IdeError::cancelled());
+                    }
+                    let params = snap.pos_params(t, pos);
+                    #[derive(serde::Deserialize)]
+                    struct JavaReference {
+                        #[serde(default)]
+                        access: Option<ReferenceAccess>,
+                        location: lsp::Location,
+                        kind: ReferenceKind,
+                    }
+                    let result: IdeResult<Vec<JavaReference>> = self
+                        .call(
+                            t,
+                            "workspace/executeCommand",
+                            json!({
+                                "command": "openidea.java.usages",
+                                "arguments": [params["textDocument"]["uri"], params["position"]["line"],
+                                    params["position"]["character"], include_declaration]
+                            }),
+                            Some(&cancel),
+                            LONG_TIMEOUT,
+                        )
+                        .await;
+                    if let Err(e) = &result {
+                        *extension_error.lock() = Some(e.clone());
+                    }
+                    let rows = result?;
+                    if cancel.is_cancelled() || !self.docs.lock().get(&doc).is_some_and(|d| d.version == snap.version) {
+                        return Err(IdeError::cancelled());
+                    }
+                    let conv = self.conv(t.enc());
+                    Ok(rows
+                        .into_iter()
+                        .filter_map(|r| {
+                            conv.location(&r.location).map(|location| ClassifiedReference {
+                                location,
+                                kind: r.kind,
+                                access: r.access,
+                            })
+                        })
+                        .collect::<Vec<_>>())
+                };
+                let files = |v: &Vec<ClassifiedReference>| {
+                    v.iter().filter(|r| r.location.uri.is_none()).map(|r| r.location.path.to_path_buf()).collect()
+                };
+                let widened = if project_wide {
+                    self.widened(&snap, t, pos, &cancel, query, files).await?
+                } else {
+                    let first = query().await?;
+                    let empty = first.is_empty();
+                    scope::Widened::only(first, empty, &t.server)
+                };
+                // A changed source also invalidates an earlier answer retained by scope widening.
+                if cancel.is_cancelled() || !self.docs.lock().get(&doc).is_some_and(|d| d.version == snap.version) {
+                    return Err(IdeError::cancelled());
+                }
+                // Scope widening can retain the first answer after a failed second query.
+                if let Some(e) = extension_error.into_inner() {
+                    return Err(e);
+                }
+                let mut seen = std::collections::HashSet::new();
+                // Prefer the second query's metadata for repeated locations.
+                let classified: Vec<_> = widened
+                    .second
+                    .into_iter()
+                    .flatten()
+                    .chain(widened.first)
+                    .filter(|r| seen.insert(r.location.clone()))
+                    .collect();
+                let locations: Vec<Location> = classified.iter().map(|r| r.location.clone()).collect();
+                self.note_virtual(&t.server, locations.iter().map(|l| l.uri.as_deref()));
+                Ok(References { locations, classified, incomplete: widened.incomplete })
+            }
+            .await;
+            match classified {
+                Ok(references) => return Ok(references),
+                Err(e) => {
+                    if e.kind == ErrorKind::Cancelled
+                        || cancel.is_cancelled()
+                        || !self.docs.lock().get(&doc).is_some_and(|d| d.version == snap.version)
+                    {
+                        return Err(IdeError::cancelled());
+                    }
+                    if !self.java_usages_warned.swap(true, Ordering::Relaxed) {
+                        tracing::warn!("Java usages extension failed; using standard references: {e}");
+                    }
+                }
+            }
+        }
        let requests = targets.iter().map(|t| {
            let (snap, cancel) = (&snap, &cancel);
            async move {
@@ -1420,6 +1555,92 @@ impl LspManager {
        Ok(())
    }

+    async fn command_target(&self, doc: DocId, server: ide_core::ServerId, name: &str) -> IdeResult<Target> {
+        let snap = self.snapshot(doc)?;
+        self.ready_targets(&snap.servers, |c| c.commands().iter().any(|c| c == name))
+            .await
+            .into_iter()
+            .find(|t| t.server.id == server)
+            .ok_or_else(|| IdeError::unavailable(format!("no language server provides command `{name}`")))
+    }
+
+    /// Resolve only after explicit invocation; previews must never ask for input.
+    pub async fn resolve_command(
+        &self,
+        doc: DocId,
+        server: ide_core::ServerId,
+        command: Command,
+        answers: Vec<FormAnswer>,
+        cancel: CancellationToken,
+    ) -> IdeResult<Option<CommandForm>> {
+        let t = self.command_target(doc, server, &command.command).await?;
+        let interactive = t.server.name == "gopls"
+            && t.caps()
+                .raw
+                .pointer("/experimental/interactiveResolveProvider/kinds")
+                .and_then(Value::as_array)
+                .is_some_and(|k| k.iter().any(|v| v == "command"));
+        if !interactive {
+            return Ok(None);
+        }
+        let params = json!({ "command": command.command, "arguments": command.arguments, "formAnswers": answers });
+        let response: Value = self.call(&t, "command/resolve", params, Some(&cancel), LONG_TIMEOUT).await?;
+        let parse_error = |e: serde_json::Error| IdeError::internal(format!("invalid command form: {e}"));
+        let fields = response.get("formFields").filter(|v| !v.is_null()).cloned().unwrap_or(json!([]));
+        for field in fields.as_array().into_iter().flatten() {
+            if field.pointer("/type/kind").and_then(Value::as_str) != Some("string") {
+                return Err(IdeError::unavailable("unsupported command input type"));
+            }
+        }
+        Ok(Some(CommandForm {
+            command: Command {
+                title: command.title,
+                command: response
+                    .get("command")
+                    .and_then(Value::as_str)
+                    .ok_or_else(|| IdeError::internal("command form omitted command"))?
+                    .to_owned(),
+                arguments: serde_json::from_value(response.get("arguments").cloned().unwrap_or(json!([])))
+                    .map_err(parse_error)?,
+            },
+            form_fields: serde_json::from_value(fields).map_err(parse_error)?,
+            form_answers: serde_json::from_value(
+                response.get("formAnswers").filter(|v| !v.is_null()).cloned().unwrap_or(json!([])),
+            )
+            .map_err(parse_error)?,
+        }))
+    }
+
+    /// Execute on the originating server and return files from successfully applied edits.
+    pub async fn execute_action_command(
+        &self,
+        doc: DocId,
+        server: ide_core::ServerId,
+        command: Command,
+        answers: Vec<FormAnswer>,
+        cancel: CancellationToken,
+    ) -> IdeResult<Vec<PathBuf>> {
+        let t = self.command_target(doc, server, &command.command).await?;
+        let open_created = t.server.name == "gopls" && command.command == "gopls.add_test";
+        let mut edits = self.applied_edits.subscribe();
+        let mut params = json!({ "command": command.command, "arguments": command.arguments });
+        if !answers.is_empty() {
+            params["formAnswers"] = json!(answers);
+        }
+        let _: Value = self.call(&t, "workspace/executeCommand", params, Some(&cancel), LONG_TIMEOUT).await?;
+        let mut created = Vec::new();
+        while let Ok((origin, edit)) = edits.try_recv() {
+            if open_created && origin == server {
+                for file in edit.files {
+                    if let ide_core::FileEdit::Create { path, .. } = file {
+                        created.push(path.into());
+                    }
+                }
+            }
+        }
+        Ok(created)
+    }
+
    pub async fn prepare_rename(&self, doc: DocId, pos: Pos) -> IdeResult<Option<Range>> {
        let (snap, targets) = self.doc_targets(doc, "rename", |c| c.has("renameProvider")).await?;
        let mut out = Outcome::new();
@@ -1665,6 +1886,12 @@ impl LspManager {
        }
    }

+    /// Checks initialized capabilities, including dynamic registrations, before choosing a formatter.
+    pub async fn can_format(&self, doc: DocId) -> IdeResult<bool> {
+        let snap = self.snapshot(doc)?;
+        Ok(!self.ready_targets(&snap.servers, |c| c.has("documentFormattingProvider")).await.is_empty())
+    }
+
    pub async fn format(&self, doc: DocId, range: Option<Range>, options: FormatOptions) -> IdeResult<Vec<TextEdit>> {
        let (method, cap, feature) = match range {
            None => ("textDocument/formatting", "documentFormattingProvider", "formatting"),
@@ -1945,6 +2172,7 @@ impl LspManager {
            return Ok(d.clone());
        }
        let scheme = virtual_doc::scheme(uri).to_owned();
+        let class_file = scheme == "jdt" || (scheme == "file" && uri.ends_with(".class"));
        let origin = self.origin_server(uri);
        let mut servers: Vec<Arc<Server>> = origin.iter().cloned().collect();
        servers.extend(self.servers.lock().iter().filter(|s| Some(s.id) != origin.as_ref().map(|o| o.id)).cloned());
@@ -1953,7 +2181,7 @@ impl LspManager {
        for t in &targets {
            let languages = t.server.languages();
            let serves_scheme = t.caps().content_schemes().contains(&scheme);
-            let result: IdeResult<Option<String>> = if serves_scheme {
+            let result: IdeResult<Option<String>> = if serves_scheme && !class_file {
                self.call::<_, Option<Value>>(
                    t,
                    "workspace/textDocumentContent",
@@ -1963,7 +2191,7 @@ impl LspManager {
                )
                .await
                .map(|v| v.and_then(|v| v.get("text").and_then(Value::as_str).map(str::to_owned)))
-            } else if scheme == "jdt" && languages.iter().any(|l| l.as_str() == "java") {
+            } else if class_file && languages.iter().any(|l| l.as_str() == "java") {
                self.call::<_, Option<String>>(t, "java/classFileContents", json!({ "uri": uri }), None, LONG_TIMEOUT)
                    .await
            } else {
@@ -2081,6 +2309,7 @@ impl LspManager {
            let without_settings = |c: &LanguageServerConfig| LanguageServerConfig { settings: None, ..c.clone() };
            if let Some(run) = s.running()
                && without_settings(&next) == without_settings(&current)
+                && !jdtls::source_paths_removed(&current, &next)
            {
                s.set_effective_config(next);
                let params = json!({ "settings": handler::all_settings(&s.effective_config()) });
@@ -99,6 +99,8 @@ pub struct Server {
    /// Woken when the last `$/progress` task ends.
    idle_notify: Notify,
    transient: Mutex<HashMap<PathBuf, Transient>>,
+    pub java_build_lock: Arc<tokio::sync::Mutex<()>>,
+    pub java_autobuild_suspended: std::sync::atomic::AtomicBool,
    pub external_project: tokio::sync::Mutex<crate::external_project::State>,
    pub external_diagnostics: std::sync::atomic::AtomicBool,
    pub external_refresh_queued: std::sync::atomic::AtomicBool,
@@ -126,6 +128,8 @@ impl Server {
            published_notify: Notify::new(),
            idle_notify: Notify::new(),
            transient: Mutex::new(HashMap::new()),
+            java_build_lock: Arc::new(tokio::sync::Mutex::new(())),
+            java_autobuild_suspended: std::sync::atomic::AtomicBool::new(false),
            external_project: tokio::sync::Mutex::new(Default::default()),
            external_diagnostics: std::sync::atomic::AtomicBool::new(false),
            external_refresh_queued: std::sync::atomic::AtomicBool::new(false),
@@ -134,7 +138,13 @@ impl Server {

    /// Configuration of the current (or last) instance; the base config before the first launch.
    pub fn effective_config(&self) -> LanguageServerConfig {
-        self.effective.lock().clone().unwrap_or_else(|| self.config.clone())
+        let mut config = self.effective.lock().clone().unwrap_or_else(|| self.config.clone());
+        if self.java_autobuild_suspended.load(std::sync::atomic::Ordering::SeqCst) {
+            let mut settings = crate::handler::all_settings(&config);
+            settings["java"]["autobuild"]["enabled"] = serde_json::json!(false);
+            config.settings = Some(settings);
+        }
+        config
    }

    pub fn set_effective_config(&self, config: LanguageServerConfig) {
@@ -553,6 +563,19 @@ mod tests {
        assert_eq!(s.record_crash(), Some(Duration::from_millis(500)));
    }

+    #[test]
+    fn external_build_suspends_only_the_effective_autobuild_setting() {
+        let mut config: LanguageServerConfig = toml::from_str("name = \"jdtls\"\ncommand = \"jdtls\"").unwrap();
+        config.settings = Some(serde_json::json!({"java": {"autobuild": {"enabled": true}, "other": "kept"}}));
+        let server = Server::new(config.clone(), PathBuf::from("/p"), LanguageId::new("java"));
+        server.java_autobuild_suspended.store(true, std::sync::atomic::Ordering::SeqCst);
+        let settings = crate::handler::all_settings(&server.effective_config());
+        assert_eq!(settings["java"]["autobuild"]["enabled"], false);
+        assert_eq!(settings["java"]["other"], "kept");
+        server.java_autobuild_suspended.store(false, std::sync::atomic::Ordering::SeqCst);
+        assert_eq!(server.effective_config(), config);
+    }
+
    #[tokio::test(flavor = "multi_thread")]
    async fn a_failed_start_reports_its_status_before_waiters_wake() {
        // The race behind "jdtls is not ready (Starting)": a request woken by the
@@ -145,6 +145,34 @@ pub struct Command {
    pub arguments: Vec<serde_json::Value>,
 }

+/// The string form supported by gopls's experimental interactive command protocol.
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct FormAnswer {
+    pub id: String,
+    pub value: String,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct FormField {
+    pub id: String,
+    pub description: String,
+    pub required: bool,
+    #[serde(default)]
+    pub default: Option<String>,
+    #[serde(default)]
+    pub error: Option<String>,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct CommandForm {
+    pub command: Command,
+    pub form_fields: Vec<FormField>,
+    pub form_answers: Vec<FormAnswer>,
+}
+
 /// One `textDocument/inlineCompletion` suggestion (ghost text at the caret).
 #[derive(Clone, Debug, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
@@ -191,6 +219,9 @@ pub struct CodeActionQuery {
 pub struct FormatOptions {
    pub tab_size: u32,
    pub insert_spaces: bool,
+    #[serde(default)]
+    #[specta(optional)]
+    pub on_save: bool,
 }

 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
@@ -307,7 +338,7 @@ pub struct VirtualDocument {
    pub title: String,
    /// Origin shown in the tooltip / banner, e.g. the jar path.
    pub description: Option<String>,
-    /// Generated by a decompiler / disassembler rather than real sources.
+    /// Generated Java from a decompiler, rather than real source or a disassembler stub.
    pub decompiled: bool,
 }

@@ -338,6 +369,10 @@ pub enum ReferencesIncomplete {
 #[derive(Clone, Debug, Default, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 pub struct References {
+    /// Semantic classifications supplied by a language extension. Missing entries are unknown.
+    #[serde(default)]
+    #[specta(optional)]
+    pub classified: Vec<ClassifiedReference>,
    pub locations: Vec<Location>,
    pub incomplete: Option<ReferencesIncomplete>,
 }
@@ -355,3 +390,31 @@ pub struct CallHierarchy {
    pub items: Vec<HierarchyItem>,
    pub incomplete: Option<ReferencesIncomplete>,
 }
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum ReferenceKind {
+    Getter,
+    Setter,
+    Field,
+    Unknown,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum ReferenceAccess {
+    Read,
+    Write,
+    ReadWrite,
+    Unknown,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+pub struct ClassifiedReference {
+    /// Optional for older Java extensions; missing means unclassified.
+    #[serde(default)]
+    #[specta(optional)]
+    pub access: Option<ReferenceAccess>,
+    pub location: Location,
+    pub kind: ReferenceKind,
+}
@@ -1,21 +1,29 @@
 //! Virtual documents: read-only contents a language server provides for a
-//! non-`file:` URI (library classes from `jdt://`, `workspace/textDocumentContent`).
+//! URI (library classes from `jdt://`, disk classes from `file://`, or
+//! `workspace/textDocumentContent`).

 use percent_encoding::percent_decode_str;

-/// Markers decompilers / disassemblers put at the top of generated code.
-const GENERATED_MARKERS: [&str; 5] = [
-    "generated by the fernflower decompiler",
-    "failed to get sources",
-    "decompiled with cfr",
-    "decompiled with procyon",
-    "generated by the disassembler",
-];
-
-/// Whether `text` is decompiled / disassembled code rather than real source.
+/// Recognize decompiler headers, without treating disassembler stubs as Java source.
 pub fn is_decompiled(text: &str) -> bool {
-    let head: String = text.chars().take(600).collect::<String>().to_ascii_lowercase();
-    GENERATED_MARKERS.iter().any(|m| head.contains(m))
+    let head: String = text.chars().take(600).collect();
+    head.lines()
+        .take(12)
+        .take_while(|line| {
+            let line = line.trim();
+            line.is_empty() || line.starts_with("//") || line.starts_with("/*") || line.starts_with('*')
+        })
+        .any(|line| {
+            let line = line.trim().trim_start_matches('/').trim_start_matches('*').trim().to_ascii_lowercase();
+            [
+                "source code is unavailable, and was generated by the fernflower decompiler.",
+                "source code is decompiled from a .class file using fernflower decompiler",
+                "decompiled with cfr",
+                "decompiled with procyon",
+            ]
+            .iter()
+            .any(|marker| line.starts_with(marker))
+        })
 }

 /// `scheme` of a URI (`jdt` for `jdt://…`).
@@ -34,7 +42,16 @@ fn segments(uri: &str) -> Vec<String> {
 /// Editor tab title: the last path segment; a class file whose real source
 /// was found is shown as `.java` (IDEA: `String.java` vs `String.class`).
 pub fn title(uri: &str, decompiled: bool) -> String {
-    let name = segments(uri).pop().unwrap_or_else(|| uri.to_owned());
+    let mut name = segments(uri).pop().unwrap_or_else(|| uri.to_owned());
+    // Recent jdtls versions use a .java path even for decompiled class handles.
+    if decompiled
+        && scheme(uri) == "jdt"
+        && name.ends_with(".java")
+        && uri.split_once('?').is_some_and(|(_, q)| percent_decode_str(q).decode_utf8_lossy().contains(".class"))
+    {
+        name.truncate(name.len() - 5);
+        name.push_str(".class");
+    }
    match name.strip_suffix(".class") {
        Some(stem) if !decompiled && scheme(uri) == "jdt" => format!("{stem}.java"),
        _ => name,
@@ -68,6 +85,19 @@ pub fn description(uri: &str) -> Option<String> {
    }
 }

+/// Check both the package and actual archive, so duplicate type names never pick another jar.
+pub(crate) fn matches_class(uri: &str, jar: &std::path::Path, package: &str, name: &str) -> bool {
+    let segs = segments(uri);
+    scheme(uri) == "jdt"
+        && (package.is_empty() && segs.len() == 3 || segs.get(2).is_some_and(|s| s == package))
+        && segs.last().is_some_and(|s| s == &format!("{name}.class") || s == &format!("{name}.java"))
+        && description(uri).is_some_and(|p| {
+            let path = std::path::Path::new(&p);
+            path == jar
+                || dunce::canonicalize(path).ok().zip(dunce::canonicalize(jar).ok()).is_some_and(|(a, b)| a == b)
+        })
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -84,6 +114,30 @@ mod tests {

    #[test]
    fn jdt_description() {
+        assert!(matches_class(
+            JDT,
+            std::path::Path::new("/Users/me/.m2/repository/spring-boot-4.1.1.jar"),
+            "org.springframework.boot",
+            "SpringApplication"
+        ));
+        assert!(!matches_class(
+            JDT,
+            std::path::Path::new("/elsewhere/spring-boot-4.1.1.jar"),
+            "org.springframework.boot",
+            "SpringApplication"
+        ));
+        assert!(!matches_class(
+            JDT,
+            std::path::Path::new("/Users/me/.m2/repository/spring-boot-4.1.1.jar"),
+            "other.package",
+            "SpringApplication"
+        ));
+        assert!(matches_class(
+            "jdt://contents/a.jar//C.java?=p/%5C/m2%5C/a.jar%3C%28C.class",
+            std::path::Path::new("/m2/a.jar"),
+            "",
+            "C"
+        ));
        assert_eq!(description(JDT).as_deref(), Some("/Users/me/.m2/repository/spring-boot-4.1.1.jar"));
        assert_eq!(
            description(
@@ -98,10 +152,18 @@ mod tests {

    #[test]
    fn detects_generated_code() {
+        assert!(is_decompiled(
+            "// Source code is decompiled from a .class file using FernFlower decompiler (from Intellij IDEA).\npackage a;"
+        ));
+        assert!(!is_decompiled("package a;\n// generated by the fernflower decompiler"));
+        assert!(!is_decompiled("// Documentation about code generated by the Fernflower decompiler.\npackage a;"));
+        let recent = "jdt://contents/a.jar/p/C.java?=p/a.jar%3Cp%28C.class";
+        assert_eq!(title(recent, true), "C.class");
+        assert_eq!(title(recent, false), "C.java");
        assert!(is_decompiled(
            "// Source code is unavailable, and was generated by the Fernflower decompiler.\npackage a;"
        ));
-        assert!(is_decompiled(
+        assert!(!is_decompiled(
            "// Failed to get sources. Instead, stub sources have been generated by the disassembler."
        ));
        assert!(!is_decompiled("/*\n * Copyright 2012-2024 the original author or authors.\n */\npackage a;"));
@@ -0,0 +1,25 @@
+package demo;
+import java.util.List;
+import java.util.function.Function;
+@Deprecated @SuppressWarnings("unused") public class FormatterSample {
+@Deprecated @SuppressWarnings("unused") private String first="first";
+private String second="second";
+/** A description which remains on a very long single line to check whether formatting introduces wrapping when the right margin is exceeded with ordinary words in a JavaDoc comment. */
+@Deprecated @SuppressWarnings("unused") public String combine(@Deprecated @SuppressWarnings("unused") String firstParameterWithAVeryLongName, String secondParameterWithAVeryLongName, String thirdParameterWithAVeryLongName){if(firstParameterWithAVeryLongName==null){return "none";}else{try{return List.of(firstParameterWithAVeryLongName,secondParameterWithAVeryLongName,thirdParameterWithAVeryLongName).stream().map(value->value.trim()).filter(value->!value.isEmpty()).findFirst().orElse("none");}catch(RuntimeException problem){throw problem;}finally{System.out.println("done");}}}
+public void multiline(String firstParameter,
+String secondParameter,
+String thirdParameter){
+combine(firstParameter,
+secondParameter,
+thirdParameter);
+List.of(firstParameter, secondParameter)
+.stream()
+.map(value->value.trim())
+.forEach(System.out::println);
+}
+public void retained(String firstParameter, // retain declaration break
+String secondParameter){combine(firstParameter, // retain call break
+secondParameter, "third");}
+public void arrays(){int[] values=new int[]{1,2,3};int[] empty=new int[]{};Function<String,String> clean=value->{return value.trim();};Runnable run=()->{System.out.println(values.length);};}
+// A comment which intentionally exceeds the right margin and should remain unwrapped with the built-in profile even when it contains many ordinary words and spaces to split on.
+}
@@ -0,0 +1,65 @@
+package demo;
+
+import java.util.List;
+import java.util.function.Function;
+
+@Deprecated
+@SuppressWarnings("unused")
+public class FormatterSample {
+    @Deprecated
+    @SuppressWarnings("unused")
+    private String first = "first";
+    private String second = "second";
+
+    /** A description which remains on a very long single line to check whether formatting introduces wrapping when the right margin is exceeded with ordinary words in a JavaDoc comment. */
+    @Deprecated
+    @SuppressWarnings("unused")
+    public String combine(@Deprecated @SuppressWarnings("unused") String firstParameterWithAVeryLongName,
+                          String secondParameterWithAVeryLongName, String thirdParameterWithAVeryLongName) {
+        if (firstParameterWithAVeryLongName == null) {
+            return "none";
+        } else {
+            try {
+                return List
+                        .of(firstParameterWithAVeryLongName, secondParameterWithAVeryLongName,
+                                thirdParameterWithAVeryLongName)
+                        .stream().map(value -> value.trim()).filter(value -> !value.isEmpty()).findFirst()
+                        .orElse("none");
+            } catch (RuntimeException problem) {
+                throw problem;
+            } finally {
+                System.out.println("done");
+            }
+        }
+    }
+
+    public void multiline(String firstParameter,
+                          String secondParameter,
+                          String thirdParameter) {
+        combine(firstParameter,
+                secondParameter,
+                thirdParameter);
+        List.of(firstParameter, secondParameter)
+                .stream()
+                .map(value -> value.trim())
+                .forEach(System.out::println);
+    }
+
+    public void retained(String firstParameter, // retain declaration break
+                         String secondParameter) {
+        combine(firstParameter, // retain call break
+                secondParameter, "third");
+    }
+
+    public void arrays() {
+        int[] values = new int[]{1, 2, 3};
+        int[] empty = new int[]{};
+        Function<String, String> clean = value -> {
+            return value.trim();
+        };
+        Runnable run = () -> {
+            System.out.println(values.length);
+        };
+    }
+    // A comment which intentionally exceeds the right margin and should remain unwrapped with the built-in profile even when it contains many ordinary words and spaces to split on.
+}
@@ -27,6 +27,7 @@ struct MockState {
    /// uri → text as reconstructed by the mock from didOpen/didChange.
    docs: Mutex<HashMap<String, String>>,
    responses: Mutex<HashMap<String, Value>>,
+    errors: Mutex<HashMap<String, (i64, String)>>,
    /// Computes a response from the request and the open documents (before `responses`).
    responder: Mutex<Option<Responder>>,
    peer: Mutex<Option<Peer>>,
@@ -122,6 +123,9 @@ impl Handler for MockHandler {
            "initialize" => Ok(json!({ "capabilities": s.caps.lock().clone(), "serverInfo": { "name": "mock" } })),
            "shutdown" => Ok(Value::Null),
            _ => {
+                if let Some(error) = s.errors.lock().get(method).cloned() {
+                    return Err(error);
+                }
                let responder = s.responder.lock().clone();
                if let Some(v) = responder.and_then(|f| f(s, method, &params)) {
                    return Ok(v);
@@ -248,6 +252,7 @@ fn harness_configured(
        indent: None,
        ui_mode: None,
        framework_ui_modes: Vec::new(),
+        formatter: None,
        tree_sitter: None,
        language_servers: servers
            .iter()
@@ -1012,6 +1017,140 @@ async fn settings_changes_reach_servers_without_restarts() {
    assert_eq!(s.launches.load(Ordering::SeqCst), 1);
 }

+#[tokio::test(flavor = "multi_thread")]
+async fn java_formatter_profiles_reach_initialization_and_live_configuration_without_restart() {
+    let h = harness_configured("java", "java", &[("jdtls", incremental_caps())], |cfg| {
+        cfg.initialization_options = Some(
+            toml::Value::try_from(json!({
+                "settings": {"java": {"autobuild": {"enabled": false}}}
+            }))
+            .unwrap(),
+        );
+    });
+    let data = tempfile::tempdir().unwrap();
+    std::fs::write(h.root.join("custom.xml"), "<profiles/>").unwrap();
+    let style = Arc::new(Mutex::new(ide_core::editor_settings::LanguageCodeStyle {
+        formatter: Some("intellij".into()),
+        formatter_path: Some("custom.xml".into()),
+        ..Default::default()
+    }));
+    h.mgr.set_config_hook(Box::new({
+        let style = style.clone();
+        let root = h.root.clone();
+        let data = data.path().to_path_buf();
+        move |cfg, _| ide_lsp::jdtls::configure_formatter(cfg, Some(&style.lock()), &root, &data, None).unwrap()
+    }));
+    h.open("Main.java", "public class Main {}");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let state = h.launcher.state("jdtls");
+    let init = state.requested("initialize")[0].clone();
+    assert_eq!(
+        init["initializationOptions"]["settings"]["java"]["format"]["settings"]["profile"],
+        "OpenIDEA IntelliJ IDEA"
+    );
+    for mode in ["custom", "default", "intellij", "default"] {
+        style.lock().formatter = Some(mode.into());
+        h.mgr.reconfigure().await;
+        let expected = match mode {
+            "custom" => uri_of(&h.root.join("custom.xml")),
+            "intellij" => uri_of(&data.path().join("lsp/jdtls/intellij.xml")),
+            _ => String::new(),
+        };
+        eventually(|| {
+            state
+                .notified("workspace/didChangeConfiguration")
+                .last()
+                .is_some_and(|p| p["settings"]["java"]["format"]["settings"]["url"] == expected)
+        })
+        .await;
+        let result: Value = state
+            .peer()
+            .request(
+                "workspace/configuration",
+                json!({
+                    "items": [{"section": "java.format.settings"}, {"section": "java.autobuild.enabled"}]
+                }),
+                None,
+            )
+            .await
+            .unwrap();
+        assert_eq!(result[0]["url"], expected);
+        assert_eq!(result[0]["profile"], if mode == "intellij" { "OpenIDEA IntelliJ IDEA" } else { "" });
+        assert_eq!(result[1], false);
+        assert_eq!(state.launches.load(Ordering::SeqCst), 1);
+    }
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn java_source_paths_reach_initialization_live_configuration_and_builds() {
+    let h = harness_configured("java", "java", &[("jdtls", incremental_caps())], |cfg| {
+        cfg.initialization_options = Some(
+            toml::Value::try_from(json!({
+                "bundles": [], "settings": {"java": {"project": {"referencedLibraries": ["lib/**/*.jar"]}}}
+            }))
+            .unwrap(),
+        );
+    });
+    let paths = Arc::new(Mutex::new(Some(vec!["src/main/java".into()])));
+    h.mgr.set_config_hook(Box::new({
+        let paths = paths.clone();
+        move |cfg, _| ide_lsp::jdtls::configure_source_paths(cfg, paths.lock().clone())
+    }));
+    let (_, file) = h.open("Main.java", "public class Main {}");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let state = h.launcher.state("jdtls");
+    let init = state.requested("initialize")[0].clone();
+    assert_eq!(init["initializationOptions"]["settings"]["java"]["project"]["sourcePaths"], json!(["src/main/java"]));
+    assert_eq!(init["initializationOptions"]["triggerFiles"], json!([uri_of(&file)]));
+    *paths.lock() = Some(vec!["generated".into(), "tests".into()]);
+    h.mgr.reconfigure().await;
+    eventually(|| {
+        state
+            .notified("workspace/didChangeConfiguration")
+            .last()
+            .is_some_and(|p| p["settings"]["java"]["project"]["sourcePaths"] == json!(["generated", "tests"]))
+    })
+    .await;
+    let notification = state.notified("workspace/didChangeConfiguration").pop().unwrap();
+    assert_eq!(notification["settings"]["java"]["project"]["referencedLibraries"], json!(["lib/**/*.jar"]));
+    assert_eq!(state.launches.load(Ordering::SeqCst), 1);
+    state.respond("java/buildWorkspace", json!(1));
+    assert_eq!(
+        h.mgr.java_build(&h.root, &Default::default()).await.unwrap(),
+        ide_lsp::jdtls::JavaBuildStatus::Succeeded
+    );
+    assert_eq!(state.requested("java/buildWorkspace"), vec![json!(false)]);
+
+    // Removing the last hint restores importer inference. Omitting a setting
+    // in didChangeConfiguration would retain jdtls's previous preference.
+    *paths.lock() = None;
+    h.mgr.reconfigure().await;
+    eventually(|| state.launches.load(Ordering::SeqCst) == 2).await;
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let init = state.requested("initialize").pop().unwrap();
+    assert!(init["initializationOptions"]["settings"]["java"]["project"].get("sourcePaths").is_none());
+    assert_eq!(init["initializationOptions"]["triggerFiles"], json!([uri_of(&file)]));
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn unmanaged_java_run_imports_sources_without_an_open_editor() {
+    let h = harness_for("java", "java", &[("jdtls", incremental_caps())], &[]);
+    std::fs::create_dir_all(h.root.join("src/demo")).unwrap();
+    let file = h.root.join("src/demo/Main.java");
+    std::fs::write(&file, "package demo; public class Main {}").unwrap();
+    h.mgr.set_config_hook(Box::new(|cfg, _| {
+        ide_lsp::jdtls::configure_source_paths(cfg, Some(vec!["src".into()]));
+    }));
+    let state = h.launcher.state("jdtls");
+    state.respond("java/buildWorkspace", json!(1));
+    assert_eq!(
+        h.mgr.java_build(&h.root, &Default::default()).await.unwrap(),
+        ide_lsp::jdtls::JavaBuildStatus::Succeeded
+    );
+    assert_eq!(state.requested("initialize")[0]["initializationOptions"]["triggerFiles"], json!([uri_of(&file)]));
+    assert!(state.notified("textDocument/didOpen").is_empty());
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn fallback_servers_only_run_when_the_preferred_one_is_missing() {
    // Preferred installed: the alternative is never started.
@@ -1174,12 +1313,17 @@ async fn navigation_rename_format_and_decorations() {
    assert!(matches!(&edit.files[0], FileEdit::Edit { edits, .. } if edits.len() == 2));
    assert_eq!(s.requested("textDocument/rename")[0]["newName"], "bar");

+    assert!(h.mgr.can_format(doc).await.unwrap());
    s.respond("textDocument/formatting", json!([{ "range": r(0,10,0,11), "newText": "\n}" }]));
-    let edits = h.mgr.format(doc, None, FormatOptions { tab_size: 2, insert_spaces: true }).await.unwrap();
+    let edits =
+        h.mgr.format(doc, None, FormatOptions { tab_size: 2, insert_spaces: true, on_save: false }).await.unwrap();
    assert_eq!(edits[0].range, rng(0, 10, 0, 11));
    assert_eq!(s.requested("textDocument/formatting")[0]["options"], json!({ "tabSize": 2, "insertSpaces": true }));
    assert!(
-        h.mgr.format(doc, Some(rng(0, 0, 1, 0)), FormatOptions { tab_size: 2, insert_spaces: true }).await.is_err()
+        h.mgr
+            .format(doc, Some(rng(0, 0, 1, 0)), FormatOptions { tab_size: 2, insert_spaces: true, on_save: false })
+            .await
+            .is_err()
    );

    s.respond("textDocument/semanticTokens/full", json!({ "data": [0, 3, 3, 0, 1, 1, 0, 3, 0, 0] }));
@@ -1543,6 +1687,61 @@ async fn jdt_class_file_contents() {
    assert_eq!(vd.title, "Lib.class");
    assert_eq!(vd.language_id.as_str(), "java");
    assert_eq!(vd.description.as_deref(), Some("/m2/lib-1.0.jar"));
+    let source_uri = jdt.replace("Lib.class", "WithSources.class");
+    s.respond(
+        "java/classFileContents",
+        json!("/* Copyright library author */\npackage org.example;\npublic class WithSources {}"),
+    );
+    let source = h.mgr.virtual_document(&source_uri).await.unwrap();
+    assert!(!source.decompiled);
+    assert_eq!(source.title, "WithSources.java");
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn class_file_opening_routes_sources_and_binary_documents() {
+    let mut caps = incremental_caps();
+    caps["workspaceSymbolProvider"] = json!(true);
+    let h = harness_for("java", "java", &[("jdtls", caps)], &[]);
+    h.open("App.java", "class App {}\n");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let s = h.launcher.state("jdtls");
+    let jdt = "jdt://contents/lib.jar/p/Outer.java?=demo/%5C/m2%5C/lib.jar%3Cp%28Outer.class";
+    s.respond("workspace/symbol", json!([
+        {"name":"Outer", "kind":5, "location":{"uri":jdt,"range":{"start":{"line":0,"character":0},"end":{"line":0,"character":0}}}}
+    ]));
+    let archive = Some((PathBuf::from("/m2/lib.jar"), "p/Outer$1.class".into()));
+    assert_eq!(h.mgr.java_class_file(Path::new("/m2/lib.jar!/p/Outer$1.class"), archive).await.unwrap(), jdt);
+    assert!(
+        h.mgr
+            .java_class_file(
+                Path::new("/other/lib.jar!/p/Outer.class"),
+                Some(("/other/lib.jar".into(), "p/Outer.class".into()))
+            )
+            .await
+            .is_err()
+    );
+
+    let sources = h.root.join("src/main/java");
+    std::fs::create_dir_all(sources.join("p")).unwrap();
+    let source = sources.join("p/Outer.java");
+    std::fs::write(&source, "package p; class Outer {} ").unwrap();
+    s.respond("java/classFileContents", json!("// Source code is decompiled from a .class file using FernFlower decompiler (from Intellij IDEA).\npackage p;\npublic class Outer {}"));
+    s.respond("workspace/executeCommand", json!({"org.eclipse.jdt.ls.core.sourcePaths":[sources]}));
+    for class in ["Outer", "Outer$Nested", "Outer$1"] {
+        let path = h.root.join(format!("target/classes/p/{class}.class"));
+        let resolved = h.mgr.java_class_file(&path, None).await.unwrap();
+        // Compare as paths: the manager joins the relative source path with std::path, so
+        // separators can differ from the literal "p/Outer.java" used to build `source` on Windows.
+        assert_eq!(Path::new(&resolved), source.as_path());
+    }
+    let path = h.root.join("build/classes/java/main/p/Missing.class");
+    let uri = uri_of(&path);
+    assert_eq!(h.mgr.java_class_file(&path, None).await.unwrap(), uri);
+    let vd = h.mgr.virtual_document(&uri).await.unwrap();
+    assert!(vd.decompiled);
+    assert_eq!(vd.language_id.as_str(), "java");
+    assert_eq!(vd.title, "Missing.class");
+    assert!(s.requested("java/classFileContents").iter().any(|p| p["uri"] == uri));
 }

 #[tokio::test(flavor = "multi_thread")]
@@ -1960,6 +2159,155 @@ async fn references_report_a_capped_candidate_search() {
    assert_eq!(refs.incomplete, Some(ReferencesIncomplete::TooManyFiles));
 }

+/// The Java command must participate in the same widening contract as standard LSP.
+#[tokio::test(flavor = "multi_thread")]
+async fn classified_java_references_widen_without_losing_metadata() {
+    let mut caps = incremental_caps();
+    caps["executeCommandProvider"] = json!({"commands": ["openidea.java.usages"]});
+    let h = harness_for("java", "java", &[("jdtls", caps)], &[]);
+    let s = h.launcher.state("jdtls");
+    *s.responder.lock() = Some(Arc::new(|s, method, _| {
+        (method == "workspace/executeCommand").then(|| {
+            let docs = s.docs.lock();
+            let access = if docs.len() == 1 { "read" } else { "readWrite" };
+            Value::Array(
+                docs.iter()
+                    .flat_map(|(uri, text)| {
+                        occurrences(uri, text)
+                            .into_iter()
+                            .map(|location| json!({"location": location, "kind": "field", "access": access}))
+                    })
+                    .collect(),
+            )
+        })
+    }));
+    let b = h.root.join("b.java");
+    std::fs::write(&b, "target++;").unwrap();
+    let (doc, _) = h.open("a.java", "int target;");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    eventually(|| s.docs.lock().len() == 1).await;
+    let seen = grep_candidates(&h);
+    let scoped = h.mgr.references(doc, Pos::new(0, 5), true, false, Default::default()).await.unwrap();
+    assert_eq!(scoped.locations.len(), 1);
+    assert!(seen.lock().is_empty());
+    let refs = h.mgr.references(doc, Pos::new(0, 5), true, true, Default::default()).await.unwrap();
+    assert_eq!(refs.locations.len(), 2);
+    assert_eq!(refs.classified.len(), 2);
+    assert!(refs.classified.iter().all(|r| matches!(r.access, Some(ReferenceAccess::ReadWrite))));
+    assert!(refs.classified.iter().all(|r| matches!(r.kind, ReferenceKind::Field)));
+    assert_eq!(refs.incomplete, None);
+    assert_eq!(s.requested("workspace/executeCommand").len(), 3);
+    assert!(s.requested("textDocument/references").is_empty());
+    eventually(|| uris(&s.notified("textDocument/didClose")) == vec![uri_of(&b)]).await;
+    for limit_hit in [true, false] {
+        let skipped = h.root.join("large.java");
+        std::fs::write(&skipped, " ".repeat((1 << 20) + 1)).unwrap();
+        h.mgr.set_candidates_hook(Box::new(move |_, _| ide_lsp::CandidateFiles {
+            files: vec![skipped.clone()],
+            limit_hit,
+        }));
+        let refs = h.mgr.references(doc, Pos::new(0, 5), true, true, Default::default()).await.unwrap();
+        assert_eq!(
+            refs.incomplete,
+            Some(if limit_hit { ReferencesIncomplete::TooManyFiles } else { ReferencesIncomplete::FilesSkipped })
+        );
+    }
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn failed_java_command_falls_back_to_unclassified_native_references() {
+    for project_wide in [false, true] {
+        let mut caps = incremental_caps();
+        caps["executeCommandProvider"] = json!({"commands": ["openidea.java.usages"]});
+        let h = harness_for("java", "java", &[("jdtls", caps)], &[]);
+        let s = h.launcher.state("jdtls");
+        s.errors.lock().insert("workspace/executeCommand".into(), (-32603, "NoSuchMethodError".into()));
+        *s.responder.lock() = Some(open_files_only(Vec::new()));
+        let (doc, path) = h.open("a.java", "int target;");
+        h.wait_status("jdtls", ServerStatus::Ready).await;
+        eventually(|| s.docs.lock().len() == 1).await;
+        let refs = h.mgr.references(doc, Pos::new(0, 5), true, project_wide, Default::default()).await.unwrap();
+        assert_eq!(refs.locations.len(), 1);
+        assert_eq!(refs.locations[0].path, path);
+        assert!(refs.classified.is_empty());
+        assert_eq!(s.requested("workspace/executeCommand").len(), 1);
+        assert_eq!(s.requested("textDocument/references").len(), 1);
+    }
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn failed_widened_java_command_retries_with_native_references() {
+    let mut caps = incremental_caps();
+    caps["executeCommandProvider"] = json!({"commands": ["openidea.java.usages"]});
+    let h = harness_for("java", "java", &[("jdtls", caps)], &[]);
+    let s = h.launcher.state("jdtls");
+    let native = open_files_only(Vec::new());
+    *s.responder.lock() = Some(Arc::new(move |s, method, params| {
+        if method == "workspace/executeCommand" {
+            // The initial query succeeds, but the next extension query fails.
+            s.errors.lock().insert(method.into(), (-32603, "reflection failed".into()));
+            return Some(Value::Array(
+                s.docs
+                    .lock()
+                    .iter()
+                    .flat_map(|(uri, text)| {
+                        occurrences(uri, text)
+                            .into_iter()
+                            .map(|location| json!({"location": location, "kind": "field", "access": "read"}))
+                    })
+                    .collect(),
+            ));
+        }
+        native(s, method, params)
+    }));
+    std::fs::write(h.root.join("b.java"), "target++;").unwrap();
+    grep_candidates(&h);
+    let (doc, _) = h.open("a.java", "int target;");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    eventually(|| s.docs.lock().len() == 1).await;
+    let refs = h.mgr.references(doc, Pos::new(0, 5), true, true, Default::default()).await.unwrap();
+    assert_eq!(refs.locations.len(), 2);
+    assert!(refs.classified.is_empty());
+    assert_eq!(s.requested("workspace/executeCommand").len(), 2);
+    assert_eq!(s.requested("textDocument/references").len(), 2);
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn superseded_java_command_does_not_fall_back() {
+    let mut caps = incremental_caps();
+    caps["executeCommandProvider"] = json!({"commands": ["openidea.java.usages"]});
+    let h = harness_for("java", "java", &[("jdtls", caps)], &[]);
+    let s = h.launcher.state("jdtls");
+    let (doc, _) = h.open("a.java", "int target;");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let mgr = Arc::downgrade(&h.mgr);
+    *s.responder.lock() = Some(Arc::new(move |_, method, _| {
+        if method != "workspace/executeCommand" {
+            return None;
+        }
+        mgr.upgrade().unwrap().did_change(doc, 2, &[change(rng(0, 0, 0, 0), " ")], &|| unreachable!());
+        // Invalid extension response after the source version changed.
+        Some(json!({"failed": true}))
+    }));
+    let err = h.mgr.references(doc, Pos::new(0, 5), true, false, Default::default()).await.unwrap_err();
+    assert_eq!(err.kind, ide_core::error::ErrorKind::Cancelled);
+    assert!(s.requested("textDocument/references").is_empty());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn cancelled_java_command_does_not_fall_back() {
+    let mut caps = incremental_caps();
+    caps["executeCommandProvider"] = json!({"commands": ["openidea.java.usages"]});
+    let h = harness_for("java", "java", &[("jdtls", caps)], &[]);
+    let s = h.launcher.state("jdtls");
+    s.errors.lock().insert("workspace/executeCommand".into(), (-32800, "cancelled".into()));
+    let (doc, _) = h.open("a.java", "int target;");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let err = h.mgr.references(doc, Pos::new(0, 5), true, false, Default::default()).await.unwrap_err();
+    assert_eq!(err.kind, ide_core::error::ErrorKind::Cancelled);
+    assert!(s.requested("textDocument/references").is_empty());
+}
+
 /// What each search widened with candidate files reports for the symbol at the start of `doc`.
 async fn incomplete_reports(h: &Harness, doc: DocId) -> Vec<(&'static str, Option<ReferencesIncomplete>)> {
    let at = Pos::new(0, 5);
@@ -2324,3 +2672,167 @@ async fn external_projects_are_capability_gated_and_follow_lifecycle() {
        h.mgr.shutdown_all().await;
    }
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn gopls_interactive_command_validates_before_execution_and_applies_edits() {
+    let mut caps = incremental_caps();
+    caps["experimental"] = json!({"interactiveResolveProvider": {"kinds": ["command"]}});
+    caps["executeCommandProvider"] = json!({"commands": ["gopls.implement_interface", "gopls.add_test"]});
+    let h = harness(&[("gopls", caps)]);
+    let (doc, path) = h.open("probe.mk", "type T struct{}\n");
+    h.wait_status("gopls", ServerStatus::Ready).await;
+    let s = h.launcher.state("gopls");
+    let server = h.mgr.servers()[0].id;
+    assert_eq!(
+        s.requested("initialize")[0]["capabilities"]["experimental"]["interactiveResolve"],
+        json!({"inputTypes": ["string"]})
+    );
+    let new_file = h.root.join("probe_test.go");
+    let edit = json!({"documentChanges": [{"kind": "create", "uri": uri_of(&new_file)}, {
+        "textDocument": {"uri": uri_of(&path), "version": 1},
+        "edits": [{"range": {"start": {"line": 0, "character": 0}, "end": {"line": 0, "character": 0}}, "newText": "// generated\n"}]
+    }]});
+    *s.responder.lock() = Some(Arc::new(move |s, method, p| {
+        if method == "command/resolve" {
+            let valid = p["formAnswers"][0]["value"] == "pkg.I";
+            return Some(if valid {
+                json!({"command": p["command"], "arguments": p["arguments"], "formAnswers": p["formAnswers"]})
+            } else {
+                json!({"command": p["command"], "arguments": p["arguments"], "formFields": [{"id": "interface", "description": "Enter interface", "required": true, "type": {"kind": "string"}, "error": if p["formAnswers"].as_array().is_some_and(|a| !a.is_empty()) { "Unknown interface" } else { "" }}]})
+            });
+        }
+        if method == "workspace/executeCommand" {
+            if p["command"] != "gopls.add_test" {
+                assert_eq!(p["formAnswers"], json!([{"id": "interface", "value": "pkg.I"}]));
+            }
+            let reply: Value = tokio::task::block_in_place(|| {
+                tokio::runtime::Handle::current().block_on(s.peer().request(
+                    "workspace/applyEdit",
+                    json!({"edit": edit}),
+                    None,
+                ))
+            })
+            .unwrap();
+            assert_eq!(reply, json!({"applied": true}));
+            return Some(Value::Null);
+        }
+        None
+    }));
+    let applied = Arc::new(Mutex::new(Vec::new()));
+    let received = applied.clone();
+    h.mgr.set_apply_edit_hook(Box::new(move |edit| {
+        received.lock().push(edit);
+        true
+    }));
+    let command = Command {
+        title: "Implement".into(),
+        command: "gopls.implement_interface".into(),
+        arguments: vec![json!({"location": 1})],
+    };
+    let token = ide_core::CancellationToken::new;
+    let initial = h.mgr.resolve_command(doc, server, command.clone(), vec![], token()).await.unwrap().unwrap();
+    assert_eq!(initial.form_fields[0].description, "Enter interface");
+    let invalid = h
+        .mgr
+        .resolve_command(
+            doc,
+            server,
+            command.clone(),
+            vec![FormAnswer { id: "interface".into(), value: "bad".into() }],
+            token(),
+        )
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(invalid.form_fields[0].error.as_deref(), Some("Unknown interface"));
+    assert!(applied.lock().is_empty());
+    assert!(s.requested("workspace/executeCommand").is_empty());
+    let cancelled = token();
+    cancelled.cancel();
+    let err = h.mgr.resolve_command(doc, server, command.clone(), vec![], cancelled).await.unwrap_err();
+    assert_eq!(err.kind, ide_core::error::ErrorKind::Cancelled);
+    let cancelled = token();
+    cancelled.cancel();
+    let err = h.mgr.execute_action_command(doc, server, command.clone(), vec![], cancelled).await.unwrap_err();
+    assert_eq!(err.kind, ide_core::error::ErrorKind::Cancelled);
+    assert!(applied.lock().is_empty());
+    assert!(s.requested("workspace/executeCommand").is_empty());
+    let validated = h
+        .mgr
+        .resolve_command(
+            doc,
+            server,
+            command,
+            vec![FormAnswer { id: "interface".into(), value: "pkg.I".into() }],
+            token(),
+        )
+        .await
+        .unwrap()
+        .unwrap();
+    assert!(validated.form_fields.is_empty());
+    h.mgr.execute_action_command(doc, server, validated.command, validated.form_answers, token()).await.unwrap();
+    assert_eq!(applied.lock().len(), 1);
+    let created = h
+        .mgr
+        .execute_action_command(
+            doc,
+            server,
+            Command { title: "Test".into(), command: "gopls.add_test".into(), arguments: vec![] },
+            vec![],
+            token(),
+        )
+        .await
+        .unwrap();
+    assert_eq!(created, vec![new_file]);
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn interactive_capability_is_scoped_to_gopls() {
+    let h = harness(&[("mock", incremental_caps())]);
+    let (doc, _) = h.open("probe.mk", "x\n");
+    h.wait_status("mock", ServerStatus::Ready).await;
+    let s = h.launcher.state("mock");
+    assert_eq!(s.requested("initialize")[0]["capabilities"]["experimental"], json!({}));
+    let form = h
+        .mgr
+        .resolve_command(
+            doc,
+            h.mgr.servers()[0].id,
+            Command { title: "Run".into(), command: "mock.run".into(), arguments: vec![json!(1)] },
+            vec![],
+            ide_core::CancellationToken::new(),
+        )
+        .await
+        .unwrap();
+    assert!(form.is_none());
+    assert!(s.requested("command/resolve").is_empty());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn formatting_provider_selection_tracks_dynamic_registration() {
+    let h = harness(&[("mock", json!({ "textDocumentSync": 1, "documentRangeFormattingProvider": true }))]);
+    let (doc, _) = h.open("a.mk", "hello\n");
+    h.wait_status("mock", ServerStatus::Ready).await;
+    assert!(!h.mgr.can_format(doc).await.unwrap(), "a range provider alone cannot format the whole document");
+    let peer = h.launcher.state("mock").peer();
+    peer.request::<_, Value>(
+        "client/registerCapability",
+        json!({"registrations": [
+            {"id": "formatter", "method": "textDocument/formatting"}
+        ]}),
+        None,
+    )
+    .await
+    .unwrap();
+    assert!(h.mgr.can_format(doc).await.unwrap());
+    peer.request::<_, Value>(
+        "client/unregisterCapability",
+        json!({"unregisterations": [
+            {"id": "formatter", "method": "textDocument/formatting"}
+        ]}),
+        None,
+    )
+    .await
+    .unwrap();
+    assert!(!h.mgr.can_format(doc).await.unwrap());
+}
@@ -55,12 +55,60 @@ fn lang(id: &str, ext: &str, server: LanguageServerConfig) -> LanguageConfig {
        indent: None,
        ui_mode: None,
        framework_ui_modes: Vec::new(),
+        formatter: None,
        tree_sitter: None,
        language_servers: vec![server],
        debugger: None,
    }
 }

+#[tokio::test(flavor = "multi_thread")]
+#[ignore = "requires jdtls on PATH and a compatible JDK"]
+async fn intellij_java_formatter_preserves_manual_breaks_and_wraps_long_lines() {
+    let dir = tempfile::tempdir().unwrap();
+    let root = dir.path().canonicalize().unwrap();
+    let source = include_str!("fixtures/FormatterSample.input.java");
+    let expected = include_str!("fixtures/FormatterSample.intellij.java");
+    let path = root.join("src/demo/FormatterSample.java");
+    std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+    std::fs::write(&path, source).unwrap();
+    let mut java = LanguageRegistry::load(None).unwrap().get(&LanguageId::new("java")).unwrap();
+    let server = &mut java.language_servers[0];
+    if let Ok(bin) = std::env::var("OPENIDEA_TEST_JDTLS") {
+        server.command = bin;
+    }
+    server.args.extend(["-data".into(), root.join("jdtls-workspace").to_string_lossy().into_owned()]);
+    server.settings = Some(serde_json::json!({"java": {"autobuild": {"enabled": false}}}));
+    let (mgr, events) = manager(&root, LanguageRegistry::from_configs(vec![java]));
+    mgr.set_config_hook(Box::new({
+        let root = root.clone();
+        move |cfg, _| {
+            ide_lsp::jdtls::configure_source_paths(cfg, Some(vec!["src".into()]));
+            let style = ide_core::editor_settings::LanguageCodeStyle {
+                formatter: Some("intellij".into()),
+                ..Default::default()
+            };
+            ide_lsp::jdtls::configure_formatter(cfg, Some(&style), &root, &root.join("data"), None).unwrap();
+        }
+    }));
+    let doc = DocId::next();
+    mgr.did_open(doc, &path, &LanguageId::new("java"), 1, source);
+    retry("jdtls ready", Duration::from_secs(120), || {
+        let status = last_status(&events, "jdtls");
+        if let Some((ServerStatus::Crashed | ServerStatus::Missing | ServerStatus::Misconfigured, msg)) = &status {
+            panic!("jdtls failed: {msg:?}");
+        }
+        async move { matches!(status, Some((ServerStatus::Ready | ServerStatus::Busy, _))).then_some(()) }
+    })
+    .await;
+    let edits =
+        mgr.format(doc, None, ide_lsp::types::FormatOptions { tab_size: 4, insert_spaces: true, on_save: false }).await;
+    tokio::time::timeout(Duration::from_secs(10), mgr.shutdown_all()).await.unwrap();
+    let mut document = ide_text::Document::new(source);
+    document.apply_edits(&edits.unwrap()).unwrap();
+    assert_eq!(document.text(), expected);
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn missing_binary_is_reported_with_install_hint() {
    let dir = tempfile::tempdir().unwrap();
@@ -0,0 +1,61 @@
+//! Imports from the client filesystem into a remote project, without deployment mappings.
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use ide_ssh::RemoteFs;
+use std::path::Path;
+
+/// Copies entries, preserving symlinks and empty folders. Reports skipped special files.
+pub async fn import_local(fs: &RemoteFs, from: &Path, to: &str, cancel: &CancellationToken) -> IdeResult<Vec<String>> {
+    let mut skipped = Vec::new();
+    import_entry(fs, from, to, cancel, &mut skipped).await?;
+    Ok(skipped)
+}
+
+async fn import_entry(
+    fs: &RemoteFs,
+    from: &Path,
+    to: &str,
+    cancel: &CancellationToken,
+    skipped: &mut Vec<String>,
+) -> IdeResult<()> {
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    if fs.stat(to).await?.is_some() {
+        return Err(IdeError::new(ide_core::error::ErrorKind::AlreadyExists, format!("{to} already exists")));
+    }
+    let meta = tokio::fs::symlink_metadata(from).await?;
+    if meta.is_symlink() {
+        let result = async {
+            let target = tokio::fs::read_link(from).await?;
+            let target = target.to_str().ok_or_else(|| IdeError::invalid("Link target is not valid UTF-8"))?;
+            fs.symlink(target, to).await
+        }
+        .await;
+        if let Err(e) = result {
+            skipped.push(format!("{}: {e}", from.display()));
+        }
+        return Ok(());
+    }
+    if !meta.is_file() && !meta.is_dir() {
+        skipped.push(format!("{}: skipped special file", from.display()));
+        return Ok(());
+    }
+    if meta.is_file() {
+        return fs.upload_new(from, to, cancel).await;
+    }
+    fs.create_dir(to).await?;
+    let result = async {
+        let mut entries = tokio::fs::read_dir(from).await?;
+        while let Some(entry) = entries.next_entry().await? {
+            let name = entry.file_name();
+            let name = name.to_str().ok_or_else(|| IdeError::invalid("File name is not valid UTF-8"))?;
+            Box::pin(import_entry(fs, &entry.path(), &ide_ssh::sftp::join(to, name), cancel, skipped)).await?;
+        }
+        Ok(())
+    }
+    .await;
+    if result.is_err() {
+        let _ = fs.remove(to).await;
+    }
+    result
+}
@@ -2,6 +2,7 @@
 //! configurations on run targets ([`target`]).

 pub mod deploy;
+pub mod import;
 pub mod mapping;
 pub mod service;
 pub mod target;
@@ -58,6 +58,75 @@ fn no_progress() -> impl FnMut(&str, usize, usize) + Send {
    |_, _, _| {}
 }

+#[tokio::test]
+async fn client_imports_preserve_conflicts_and_report_failure_over_sftp_and_local() {
+    let env = env().await;
+    for sftp in [false, true] {
+        let fs = if sftp { RemoteFs::new(env.session.sftp().await.unwrap()) } else { RemoteFs::Local };
+        let base =
+            if sftp { "/imports".to_owned() } else { env.server_root.join("local").to_string_lossy().into_owned() };
+        fs.mkdir_all(&base).await.unwrap();
+        let to = ide_ssh::sftp::join(&base, "copy");
+        let cancel = CancellationToken::new();
+        std::fs::create_dir_all(env.project.join("empty")).unwrap();
+        ide_remote::import::import_local(&fs, &env.project, &to, &cancel).await.unwrap();
+        assert_eq!(fs.read(&format!("{to}/src/main.py")).await.unwrap(), b"print('hi')\n");
+        assert!(fs.stat(&format!("{to}/empty")).await.unwrap().unwrap().is_dir);
+        let err = ide_remote::import::import_local(&fs, &env.project, &to, &cancel).await.unwrap_err();
+        assert_eq!(err.kind, ide_core::error::ErrorKind::AlreadyExists);
+        let file = format!("{to}/README.md");
+        assert!(fs.upload_new(&env.project.join("src/main.py"), &file, &cancel).await.is_err());
+        assert_eq!(fs.read(&file).await.unwrap(), b"# demo\n");
+        let missing =
+            ide_remote::import::import_local(&fs, &env.project.join("missing"), &format!("{base}/missing"), &cancel)
+                .await
+                .unwrap_err();
+        assert_eq!(missing.kind, ide_core::error::ErrorKind::NotFound);
+        cancel.cancel();
+        let err = ide_remote::import::import_local(&fs, &env.project, &format!("{base}/cancelled"), &cancel)
+            .await
+            .unwrap_err();
+        assert_eq!(err.kind, ide_core::error::ErrorKind::Cancelled);
+        assert!(fs.stat(&format!("{base}/cancelled")).await.unwrap().is_none());
+        #[cfg(unix)]
+        {
+            use std::os::unix::fs::PermissionsExt;
+            let source = env.project.join("links-tree");
+            std::fs::create_dir_all(&source).unwrap();
+            std::fs::write(source.join("run.sh"), "#!/bin/sh\necho imported\n").unwrap();
+            std::fs::set_permissions(source.join("run.sh"), std::fs::Permissions::from_mode(0o751)).unwrap();
+            std::os::unix::fs::symlink("run.sh", source.join("link")).unwrap();
+            std::os::unix::fs::symlink("missing", source.join("dangling")).unwrap();
+            std::os::unix::fs::symlink(".", source.join("cycle")).unwrap();
+            let socket = std::os::unix::net::UnixListener::bind(source.join("socket")).unwrap();
+            let dest = format!("{base}/links");
+            let skipped =
+                ide_remote::import::import_local(&fs, &source, &dest, &CancellationToken::new()).await.unwrap();
+            assert_eq!(skipped, vec![format!("{}: skipped special file", source.join("socket").display())]);
+            let on_disk = if sftp { env.server_root.join("imports/links") } else { std::path::PathBuf::from(&dest) };
+            for (name, target) in [("link", "run.sh"), ("dangling", "missing"), ("cycle", ".")] {
+                assert_eq!(std::fs::read_link(on_disk.join(name)).unwrap(), std::path::PathBuf::from(target));
+            }
+            assert_eq!(std::fs::metadata(on_disk.join("run.sh")).unwrap().permissions().mode() & 0o777, 0o751);
+            assert_eq!(fs.read(&format!("{dest}/run.sh")).await.unwrap(), b"#!/bin/sh\necho imported\n");
+            assert!(!on_disk.join("socket").exists());
+            let skipped = ide_remote::import::import_local(
+                &fs,
+                &source.join("socket"),
+                &format!("{base}/socket"),
+                &CancellationToken::new(),
+            )
+            .await
+            .unwrap();
+            assert_eq!(skipped.len(), 1);
+            assert!(fs.stat(&format!("{base}/socket")).await.unwrap().is_none());
+            drop(socket);
+            std::fs::remove_dir_all(source).unwrap();
+        }
+        fs.close().await;
+    }
+}
+
 #[tokio::test]
 async fn uploads_compares_syncs_and_downloads() {
    let env = env().await;
@@ -687,9 +687,9 @@ fn detect_go(root: &Path, out: &mut Vec<RunConfig>) {
        let mut seen = HashSet::new();
        for member in crate::go::work_modules(&work) {
            let dir = root.join(member);
-            let dir = dir.canonicalize().unwrap_or(dir);
+            let dir = dunce::canonicalize(&dir).unwrap_or(dir);
            if dir.join("go.mod").is_file() && seen.insert(dir.clone()) {
-                let canonical_root = root.canonicalize().unwrap_or_else(|_| root.to_path_buf());
+                let canonical_root = dunce::canonicalize(root).unwrap_or_else(|_| root.to_path_buf());
                let rel = dir.strip_prefix(&canonical_root).unwrap_or(&dir).to_path_buf();
                detect_go_module(&dir, (!rel.as_os_str().is_empty()).then_some(rel), out);
            }
@@ -494,7 +494,7 @@ mod tests {
    fn pathing_jar_runs_with_a_local_jdk() {
        let Some(home) = std::env::var_os("JAVA_HOME").map(PathBuf::from).or_else(|| {
            let java = crate::which::find_executable("java", &std::env::var_os("PATH").unwrap_or_default())?;
-            std::fs::canonicalize(java).ok()?.parent()?.parent().map(Path::to_path_buf)
+            dunce::canonicalize(java).ok()?.parent()?.parent().map(Path::to_path_buf)
        }) else {
            return;
        };
@@ -228,8 +228,7 @@ pub fn deployment(root: &Path, base: &Path, config: &RunConfig, resources_only:
                .filter(|v| !v.trim().is_empty())
                .ok_or_else(|| invalid("Choose a WAR file or exploded directory"))?;
            let path = root.join(value);
-            let path = path
-                .canonicalize()
+            let path = dunce::canonicalize(&path)
                .map_err(|e| invalid(format!("Invalid Tomcat deployment: {} ({e})", path.display())))?;
            if (kind == "war" && (!path.is_file() || !path.extension().is_some_and(|e| e.eq_ignore_ascii_case("war"))))
                || (kind == "directory" && !path.is_dir())
@@ -264,13 +263,14 @@ pub fn script_command(home: &Path, windows: bool, verb: &str) -> (String, Vec<St
 }

 pub fn prepare(root: &Path, cache: &Path, config: &mut RunConfig) -> IdeResult<()> {
-    let home = root
-        .join(config.extras.params.get("tomcatHome").ok_or_else(|| invalid("Choose a Tomcat installation directory"))?)
-        .canonicalize()?;
+    // Batch scripts and their environment variables require ordinary Windows paths.
+    let home = dunce::canonicalize(root.join(
+        config.extras.params.get("tomcatHome").ok_or_else(|| invalid("Choose a Tomcat installation directory"))?,
+    ))?;
    validate_home(&home)?;
    let base = base_dir(cache, &config.id);
    fs::create_dir_all(&base)?;
-    let base = base.canonicalize()?;
+    let base = dunce::canonicalize(&base)?;
    let doc = deployment(root, &base, config, false)?;
    let context = effective_context(config, &doc);
    let context = context_name(&context)?;
@@ -304,7 +304,7 @@ pub fn prepare(root: &Path, cache: &Path, config: &mut RunConfig) -> IdeResult<(
    config.env.insert("CATALINA_HOME".into(), home.to_string_lossy().into_owned());
    config.env.insert("CATALINA_BASE".into(), base.to_string_lossy().into_owned());
    if let Some(jre) = config.extras.params.get("jre").filter(|s| !s.trim().is_empty()) {
-        let jre = root.join(jre).canonicalize()?;
+        let jre = dunce::canonicalize(root.join(jre))?;
        config.env.insert("JAVA_HOME".into(), jre.to_string_lossy().into_owned());
        config.env.insert("JRE_HOME".into(), jre.to_string_lossy().into_owned());
    } else if let Some(java) = config.env.get("JAVA_HOME").cloned() {
@@ -432,7 +432,7 @@ mod tests {
        assert_eq!(fs::read_to_string(dest.join("WEB-INF/classes/App.class")).unwrap(), "class2");
        c.extras.params.insert("deployment".into(), "war".into());
        c.extras.params.insert("deploymentPath".into(), "web app.war".into());
-        assert_eq!(deployment(tmp.path(), &base, &c, false).unwrap(), war.canonicalize().unwrap());
+        assert_eq!(deployment(tmp.path(), &base, &c, false).unwrap(), dunce::canonicalize(&war).unwrap());
        fs::create_dir_all(tmp.path().join("WebContent")).unwrap();
        c.extras.params.insert("deployment".into(), "directory".into());
        c.extras.params.insert("deploymentPath".into(), "WebContent".into());
@@ -463,11 +463,22 @@ mod tests {
    #[test]
    fn prepares_isolated_base_and_jdwp_only_for_run() {
        let tmp = tempfile::tempdir().unwrap();
-        let home = tmp.path().join("Tomcat Home");
+        check_prepared_paths(tmp.path());
+    }
+    #[cfg(windows)]
+    #[test]
+    fn prepares_plain_windows_paths_from_verbatim_root() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = PathBuf::from(format!(r"\\?\{}", dunce::canonicalize(tmp.path()).unwrap().display()));
+        check_prepared_paths(&root);
+    }
+    fn check_prepared_paths(root: &Path) {
+        let home = root.join("Tomcat Home");
        fs::create_dir_all(home.join("bin")).unwrap();
        fs::create_dir_all(home.join("conf")).unwrap();
-        fs::create_dir_all(tmp.path().join("WebRoot")).unwrap();
+        fs::create_dir_all(root.join("WebRoot")).unwrap();
        fs::write(home.join("bin/catalina.sh"), "").unwrap();
+        fs::write(home.join("bin/catalina.bat"), "").unwrap();
        archive(
            &home.join("lib/catalina.jar"),
            &[("org/apache/catalina/util/ServerInfo.properties", "server.info=Apache Tomcat/10.1")],
@@ -486,17 +497,35 @@ mod tests {
            c.extras.params.insert(k.into(), v.into());
        }
        c.env.insert("JAVA_HOME".into(), "/jdk with spaces".into());
-        prepare(tmp.path(), &tmp.path().join("cache"), &mut c).unwrap();
+        let cache = root.join("cache");
+        prepare(root, &cache, &mut c).unwrap();
        assert_eq!(fs::read_to_string(home.join("conf/server.xml")).unwrap(), server);
        let base = PathBuf::from(&c.env["CATALINA_BASE"]);
-        assert!(base.join("conf/Catalina/localhost/app.xml").is_file());
+        let context = base.join("conf/Catalina/localhost/app.xml");
+        let doc = dunce::canonicalize(root.join("WebRoot")).unwrap();
+        assert_eq!(fs::read_to_string(&context).unwrap(), context_xml(&doc, false));
+        assert_eq!(c.env["CATALINA_HOME"], dunce::canonicalize(&home).unwrap().to_string_lossy());
+        assert_eq!(base, dunce::canonicalize(base_dir(&cache, &c.id)).unwrap());
        assert!(c.env["CATALINA_OPTS"].contains("suspend=n,address=127.0.0.1:0"));
        assert!(c.env["CATALINA_OPTS"].contains("-Xmx256m"));
        assert!(!c.env.get("JAVA_OPTS").is_some_and(|s| s.contains("jdwp")));
        assert_eq!(c.env["JRE_HOME"], "/jdk with spaces");
-        let stop = c.extras.stop_command.unwrap();
+        let stop = c.extras.stop_command.as_ref().unwrap();
        assert!(stop.contains("stop"));
        let script = if cfg!(windows) { "catalina.bat" } else { "catalina.sh" };
        assert!(stop.contains(script));
+
+        fs::create_dir_all(root.join("JDK Home")).unwrap();
+        c.extras.params.insert("jre".into(), "JDK Home".into());
+        prepare(root, &cache, &mut c).unwrap();
+        let jre = dunce::canonicalize(root.join("JDK Home")).unwrap();
+        for key in ["JAVA_HOME", "JRE_HOME"] {
+            assert_eq!(c.env[key], jre.to_string_lossy());
+        }
+        assert!(!c.command.contains(r"\\?\"));
+        assert!(c.args.iter().all(|arg| !arg.contains(r"\\?\")));
+        assert!(!c.extras.stop_command.as_ref().unwrap().contains(r"\\?\"));
+        assert!(c.env.values().all(|value| !value.contains(r"\\?\")));
+        assert!(!fs::read_to_string(context).unwrap().contains(r"\\?\"));
    }
 }
@@ -608,6 +608,21 @@ fn go_work_members_define_configs_including_deep_and_quoted_directories() {
    assert!(configs.iter().any(|c| c.id == "go:test:module with spaces"));
 }

+#[test]
+fn go_work_external_member_has_a_plain_absolute_working_directory() {
+    let dir = project(&[
+        ("workspace/go.work", "go 1.22\nuse ../external\n"),
+        ("external/go.mod", "module example.com/external\ngo 1.22\n"),
+        ("external/main.go", "package main\nfunc main() {}"),
+    ]);
+    let configs = detect(&dir.path().join("workspace"));
+    let run = configs.iter().find(|c| c.kind == "go" && !c.is_test).unwrap();
+    let cwd = run.cwd.as_deref().unwrap();
+    assert_eq!(cwd, dunce::canonicalize(dir.path().join("external")).unwrap());
+    assert!(cwd.is_absolute());
+    assert!(!cwd.to_string_lossy().starts_with(r"\\?\"));
+}
+
 #[test]
 fn go_work_parser_ignores_other_directives_comments_and_malformed_groups() {
    use ide_run::go::work_modules;
@@ -735,8 +735,8 @@ fn sh_quote(s: &str) -> String {
 }

 /// Command typed into a new terminal to activate the project virtualenv
-/// (PyCharm's Tools › Terminal › "Activate virtualenv"), for the given shell.
-pub fn terminal_activation(root: &Path, s: &Settings, shell: Option<&str>) -> Option<String> {
+/// (Tools › Terminal › "Activate virtualenv"). `shell` must be the resolved PTY shell.
+pub fn terminal_activation(root: &Path, s: &Settings, shell: &str) -> Option<String> {
    if !s.languages.python.activate_virtualenv {
        return None;
    }
@@ -744,12 +744,8 @@ pub fn terminal_activation(root: &Path, s: &Settings, shell: Option<&str>) -> Op
    if std::env::var_os("VIRTUAL_ENV").is_some_and(|v| Path::new(&v) == venv) {
        return None;
    }
-    let shell = shell
-        .map(str::to_owned)
-        .or_else(|| std::env::var("SHELL").ok())
-        .or_else(|| std::env::var("COMSPEC").ok())
-        .unwrap_or_default();
-    let name = Path::new(&shell).file_stem().map(|n| n.to_string_lossy().to_lowercase()).unwrap_or_default();
+    let name = shell.rsplit(['/', '\\']).next().unwrap_or(shell);
+    let name = Path::new(name).file_stem().map(|n| n.to_string_lossy().to_lowercase()).unwrap_or_default();
    let script = |file: &str| venv.join(bin_dir()).join(file);
    let line = match name.as_str() {
        "fish" => format!("source {}", sh_quote(&script("activate.fish").to_string_lossy())),
@@ -301,8 +301,12 @@ pub fn runtimes(jdks: &[Jdk]) -> Vec<serde_json::Value> {

 /// Stable FNV-1a hash of a path, for per-workspace directories.
 fn path_key(p: &Path) -> String {
+    text_key(&p.to_string_lossy())
+}
+
+fn text_key(text: &str) -> String {
    let mut h: u64 = 0xcbf29ce484222325;
-    for b in p.to_string_lossy().as_bytes() {
+    for b in text.as_bytes() {
        h ^= *b as u64;
        h = h.wrapping_mul(0x100000001b3);
    }
@@ -340,10 +344,15 @@ pub fn configure_jdtls(
    if !cfg.args.iter().any(|a| a == "-data") {
        // ECJ builds incrementally: classes compiled without (or with another) Lombok
        // agent would be kept, so each agent gets its own workspace and a full build.
-        let key = match agent {
+        let mut key = match agent {
            Some(jar) => format!("{}-{}", path_key(server_root), path_key(jar)),
            None => path_key(server_root),
        };
+        if let Some(paths) = cfg.settings.as_ref().and_then(|s| s.pointer("/java/project/sourcePaths")) {
+            // Invisible projects retain a cached resource tree across restarts.
+            // A different source model needs a clean import, including new folders.
+            key.push_str(&format!("-sources-{}", text_key(&paths.to_string())));
+        }
        let dir = data_dir.join("lsp").join("jdtls").join(key);
        cfg.args.extend(["-data".to_owned(), dir.to_string_lossy().into_owned()]);
    }
@@ -528,6 +537,26 @@ fn parse_java_version(v: &str) -> Option<u32> {
 mod tests {
    use super::*;

+    #[test]
+    fn unmanaged_source_models_have_separate_jdtls_workspaces() {
+        let data = tempfile::tempdir().unwrap();
+        let workspace = |paths: Option<serde_json::Value>| {
+            let mut cfg: LanguageServerConfig = toml::from_str("name = 'jdtls'\ncommand = 'jdtls'").unwrap();
+            if let Some(paths) = paths {
+                cfg.settings = Some(json!({"java": {"project": {"sourcePaths": paths}}}));
+            }
+            configure_jdtls(&mut cfg, Path::new("/project"), data.path(), &[], None, None, 25, &[], None);
+            cfg.args.windows(2).find(|a| a[0] == "-data").unwrap()[1].clone()
+        };
+        let inferred = workspace(None);
+        let source = workspace(Some(json!(["src/main/java"])));
+        let tests = workspace(Some(json!(["src/main/java", "src/test/java"])));
+        assert_ne!(inferred, source);
+        assert_ne!(source, tests);
+        assert_eq!(source, workspace(Some(json!(["src/main/java"]))));
+        assert_eq!(inferred, workspace(None), "build-tool projects retain their existing cache key");
+    }
+
    #[test]
    fn provisioning_runtime_preserves_implicit_project_jdk() {
        let data = tempfile::tempdir().unwrap();
@@ -688,6 +717,20 @@ mod tests {
        configure_jdtls(&mut plain, Path::new("/p"), Path::new("/data"), &[], None, None, JDTLS_MIN_JAVA, &[], None);
        let data = |c: &LanguageServerConfig| c.args[c.args.iter().position(|a| a == "-data").unwrap() + 1].clone();
        assert_ne!(data(&cfg), data(&plain), "a separate workspace, so everything is rebuilt with the agent");
+        let patched = Path::new("/managed/lombok-1.18.48-openidea.1.jar");
+        let mut fixed = jdtls();
+        configure_jdtls(
+            &mut fixed,
+            Path::new("/p"),
+            Path::new("/data"),
+            &[],
+            None,
+            None,
+            JDTLS_MIN_JAVA,
+            &[],
+            Some(patched),
+        );
+        assert_ne!(data(&cfg), data(&fixed), "the patch must rebuild classes compiled with the official agent");
        let before = cfg.clone();
        configure_jdtls(&mut cfg, Path::new("/p"), Path::new("/data"), &[], None, None, JDTLS_MIN_JAVA, &[], Some(jar));
        assert_eq!(cfg, before, "idempotent");
@@ -904,3 +947,143 @@ mod tests {
        assert_eq!(project_java_version(dir), Some(8));
    }
 }
+
+/// The same jar supplies the JDT command and the private Maven output redirector.
+pub fn kotlin_bridge_bundle(data_dir: &Path) -> Option<PathBuf> {
+    let extension = data_dir.join("kotlin-bridge-1.0.0.jar");
+    let bytes = include_bytes!("../../../plugins/kotlin-bridge/openidea-kotlin-bridge.jar");
+    if std::fs::read(&extension).is_ok_and(|old| old == bytes) {
+        return Some(extension);
+    }
+    let temporary = data_dir.join(format!(
+        "kotlin-bridge-{}-{}.tmp",
+        std::process::id(),
+        std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).ok()?.as_nanos()
+    ));
+    let result = std::fs::create_dir_all(data_dir)
+        .and_then(|_| std::fs::write(&temporary, bytes))
+        .and_then(|_| std::fs::rename(&temporary, &extension));
+    if let Err(error) = result {
+        let _ = std::fs::remove_file(temporary);
+        tracing::warn!("Kotlin bridge extension unavailable: {error}");
+        return std::fs::read(&extension).is_ok_and(|old| old == bytes).then_some(extension);
+    }
+    Some(extension)
+}
+
+#[cfg(test)]
+mod kotlin_bridge_bundle_tests {
+    #[test]
+    fn embeds_both_runtime_targets_and_repairs_a_damaged_installation() {
+        let directory = tempfile::tempdir().unwrap();
+        let path = super::kotlin_bridge_bundle(directory.path()).unwrap();
+        let expected = std::fs::read(&path).unwrap();
+        let mut archive = zip::ZipArchive::new(std::io::Cursor::new(&expected)).unwrap();
+        for (class, major) in [("KotlinLibraries", 65), ("IsolatedOutput", 52)] {
+            use std::io::Read;
+            let mut bytes = Vec::new();
+            archive.by_name(&format!("ai/openidea/kotlin/{class}.class")).unwrap().read_to_end(&mut bytes).unwrap();
+            assert_eq!(u16::from_be_bytes([bytes[6], bytes[7]]), major);
+        }
+        std::fs::write(&path, "incomplete").unwrap();
+        assert_eq!(super::kotlin_bridge_bundle(directory.path()), Some(path.clone()));
+        assert_eq!(std::fs::read(path).unwrap(), expected);
+    }
+}
+
+/// Installs the app-owned JDT LS command bundle, falling back to ordinary LSP on IO failure.
+pub fn usages_bundle(data_dir: &Path) -> Option<PathBuf> {
+    let extension = data_dir.join("java-usages-1.1.1.jar");
+    let bytes = include_bytes!("../../../plugins/java-usages/openidea-java-usages.jar");
+    if std::fs::read(&extension).is_ok_and(|old| old == bytes) {
+        clean_usages_bundles(data_dir, &extension);
+        return Some(extension);
+    }
+    // Write then rename: another window must never read a partially written jar.
+    let nonce = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).ok()?.as_nanos();
+    let temporary = data_dir.join(format!("java-usages-{}-{nonce}.tmp", std::process::id()));
+    let result = std::fs::create_dir_all(data_dir)
+        .and_then(|_| std::fs::write(&temporary, bytes))
+        .and_then(|_| std::fs::rename(&temporary, &extension));
+    match result {
+        Ok(()) => {
+            clean_usages_bundles(data_dir, &extension);
+            Some(extension)
+        }
+        Err(e) => {
+            let _ = std::fs::remove_file(&temporary);
+            if std::fs::read(&extension).is_ok_and(|old| old == bytes) {
+                clean_usages_bundles(data_dir, &extension);
+                return Some(extension);
+            }
+            tracing::warn!("Java usages extension unavailable; using standard references: {e}");
+            None
+        }
+    }
+}
+
+fn clean_usages_bundles(data_dir: &Path, current: &Path) {
+    let Ok(entries) = std::fs::read_dir(data_dir) else { return };
+    for entry in entries.flatten() {
+        let path = entry.path();
+        let Some(name) = path.file_name().and_then(|n| n.to_str()) else { continue };
+        let Some(suffix) = name.strip_prefix("java-usages-") else { continue };
+        let numeric = |s: &str| !s.is_empty() && s.bytes().all(|c| c.is_ascii_digit());
+        let old_jar = suffix.strip_suffix(".jar").is_some_and(|v| {
+            let parts: Vec<_> = v.split('.').collect();
+            parts.len() == 3 && parts.into_iter().all(numeric)
+        }) && path != current;
+        // Preserve recent temporary files: another window may still be installing.
+        let stale_temp = suffix
+            .strip_suffix(".tmp")
+            .and_then(|v| v.split_once('-'))
+            .is_some_and(|(pid, nonce)| numeric(pid) && numeric(nonce))
+            && entry
+                .metadata()
+                .ok()
+                .and_then(|m| m.modified().ok())
+                .and_then(|t| t.elapsed().ok())
+                .is_some_and(|age| age.as_secs() > 24 * 60 * 60);
+        if old_jar || stale_temp {
+            // A running server can hold an old bundle open on Windows.
+            let _ = std::fs::remove_file(path);
+        }
+    }
+}
+
+#[cfg(test)]
+mod usages_bundle_tests {
+    #[test]
+    fn cleans_old_bundles_and_abandoned_temporary_files_on_install_and_reuse() {
+        let dir = tempfile::tempdir().unwrap();
+        for reuse in [false, true] {
+            let old = dir.path().join("java-usages-1.0.0.jar");
+            let stale = dir.path().join("java-usages-123-456.tmp");
+            std::fs::write(&old, b"old").unwrap();
+            std::fs::write(&stale, b"partial").unwrap();
+            let times = std::fs::FileTimes::new()
+                .set_modified(std::time::SystemTime::now() - std::time::Duration::from_secs(48 * 60 * 60));
+            std::fs::File::options().write(true).open(&stale).unwrap().set_times(times).unwrap();
+            for name in ["java-usages-123-789.tmp", "java-usages-custom.jar", "other.jar", "java-usages-not-ours.tmp"] {
+                std::fs::write(dir.path().join(name), b"keep").unwrap();
+            }
+            let jar = super::usages_bundle(dir.path()).unwrap();
+            assert!(jar.exists());
+            assert!(!old.exists(), "reuse={reuse}");
+            assert!(!stale.exists(), "reuse={reuse}");
+            assert_eq!(std::fs::read_dir(dir.path()).unwrap().count(), 5);
+        }
+    }
+
+    #[test]
+    fn installs_the_exact_bundle_and_reuses_it() {
+        let dir = tempfile::tempdir().unwrap();
+        let jar = super::usages_bundle(dir.path()).unwrap();
+        assert_eq!(
+            std::fs::read(&jar).unwrap(),
+            include_bytes!("../../../plugins/java-usages/openidea-java-usages.jar")
+        );
+        assert_eq!(super::usages_bundle(dir.path()), Some(jar));
+        assert_eq!(std::fs::read_dir(dir.path()).unwrap().count(), 1);
+    }
+}
@@ -8,7 +8,7 @@
 //! result is cached until the manifests (or the relevant settings) change.
 //!
 //! Archives are listed as browsable roots (`<archive>!`, see `ide_vfs`): the
-//! JDK's `src.zip` and the Maven / Gradle dependency jars (sources jars preferred).
+//! JDK's `src.zip` and the Maven / Gradle dependency jars (source attachments resolved by JDT).

 use crate::exe;
 use crate::exec::{query, query_in, which};
@@ -248,7 +248,7 @@ fn gradle_user_home() -> Option<PathBuf> {
 }

 /// One `Maven: g:a:v` / `Gradle: g:a:v` group per dependency whose jar is in a
-/// local repository, its root being the jar (the `-sources.jar` when downloaded).
+/// local repository, its root being the binary jar so Java classes open through JDT's source provider.
 pub(crate) fn dependency_libraries(
    deps: &[BuildDependency],
    maven_repo: Option<&Path>,
@@ -286,7 +286,7 @@ pub(crate) fn maven_jar(repo: &Path, d: &BuildDependency) -> Option<PathBuf> {
        return None;
    }
    let dir = repo.join(d.group.replace('.', "/")).join(&d.artifact).join(&d.version);
-    ["-sources.jar", ".jar"]
+    [".jar", "-sources.jar"]
        .iter()
        .map(|suffix| dir.join(format!("{}-{}{suffix}", d.artifact, d.version)))
        .find(|p| p.is_file())
@@ -300,7 +300,7 @@ pub(crate) fn gradle_jar(home: &Path, d: &BuildDependency) -> Option<PathBuf> {
    let dir = home.join("caches/modules-2/files-2.1").join(&d.group).join(&d.artifact).join(&d.version);
    let mut hashes: Vec<PathBuf> = std::fs::read_dir(dir).ok()?.flatten().map(|e| e.path()).collect();
    hashes.sort();
-    ["-sources.jar", ".jar"].iter().find_map(|suffix| {
+    [".jar", "-sources.jar"].iter().find_map(|suffix| {
        let file = format!("{}-{}{suffix}", d.artifact, d.version);
        hashes.iter().map(|h| h.join(&file)).find(|p| p.is_file())
    })
@@ -1,6 +1,6 @@
 //! Lombok for jdtls: ECJ only generates Lombok members when the language
 //! server's JVM runs `-javaagent:lombok.jar`, so a project using Lombok gets the
-//! newest jar available, managed (installed by the IDE) or in the Maven / Gradle caches.
+//! app-provided jar, or falls back to the newest release in the Maven / Gradle caches.

 use crate::home_dir;
 use std::path::{Path, PathBuf};
@@ -18,7 +18,7 @@ pub enum LombokAgent {
    Missing,
    Found {
        jar: PathBuf,
-        /// `None` for the managed jar (the latest release when installed).
+        /// `None` for the app-provided jar (its version is shown by the tool registry).
        version: Option<String>,
    },
 }
@@ -64,7 +64,7 @@ pub fn agent_in_args<'a>(args: impl IntoIterator<Item = &'a str>) -> Option<Path
 }

 /// The Lombok agent for the project at `root`: the user's own (`own`, from the JVM
-/// options) wins, then `managed` (the IDE-installed jar, always attached: it is inert
+/// options) wins, then `managed` (the app-provided jar, always attached: it is inert
 /// without Lombok on the classpath), then, for a project using Lombok, the build caches
 /// (`maven_repo`, the configured Maven local repository, else the default one).
 pub fn lombok_agent(
@@ -499,6 +499,23 @@ mod tests {
        assert_eq!(managed.problem(), None);
    }

+    #[test]
+    fn the_patched_agent_wins_over_project_caches_but_respects_explicit_overrides() {
+        let tmp = tempfile::tempdir().unwrap();
+        fs::write(tmp.path().join("pom.xml"), LOMBOK_DEP).unwrap();
+        let repo = tmp.path().join("m2");
+        let cache = repo.join("org/projectlombok/lombok/1.18.48");
+        fs::create_dir_all(&cache).unwrap();
+        fs::write(cache.join("lombok-1.18.48.jar"), b"official agent").unwrap();
+        let patched = PathBuf::from("/managed/lombok-1.18.48-openidea.1.jar");
+        let selected = lombok_agent(tmp.path(), None, Some(patched.clone()), Some(repo.clone()));
+        assert_eq!(selected.jar(), Some(patched.as_path()));
+        assert_eq!(selected.problem(), None);
+        let own = PathBuf::from("/custom/lombok.jar");
+        let selected = lombok_agent(tmp.path(), Some(own.clone()), Some(patched), Some(repo));
+        assert_eq!(selected.jar(), Some(own.as_path()));
+    }
+
    #[test]
    fn picks_the_newest_cached_release() {
        let tmp = tempfile::tempdir().unwrap();
@@ -319,14 +319,40 @@ fn terminal_activation_for_project_venv() {
    }
    let tmp = tempfile::tempdir().unwrap();
    let mut s = Settings::default();
-    assert_eq!(terminal_activation(tmp.path(), &s, Some("/bin/zsh")), None);
+    assert_eq!(terminal_activation(tmp.path(), &s, "/bin/zsh"), None);
    fake_venv(tmp.path(), ".venv");
-    let line = terminal_activation(tmp.path(), &s, Some("/bin/zsh")).unwrap();
+    let line = terminal_activation(tmp.path(), &s, "/bin/zsh").unwrap();
    assert!(line.starts_with("source '") && line.ends_with("/activate'"), "{line}");
-    assert_eq!(terminal_activation(tmp.path(), &s, Some("/usr/bin/fish")), None, "no activate.fish");
-    assert_eq!(terminal_activation(tmp.path(), &s, Some("docker")), None, "not a shell");
+    assert_eq!(terminal_activation(tmp.path(), &s, "/usr/bin/fish"), None, "no activate.fish");
+    assert_eq!(terminal_activation(tmp.path(), &s, "docker"), None, "not a shell");
    s.languages.python.activate_virtualenv = false;
-    assert_eq!(terminal_activation(tmp.path(), &s, Some("/bin/zsh")), None);
+    assert_eq!(terminal_activation(tmp.path(), &s, "/bin/zsh"), None);
+}
+
+#[test]
+fn terminal_activation_for_windows_shell_paths() {
+    let tmp = tempfile::tempdir().unwrap();
+    let mut s = Settings::default();
+    s.languages.python.interpreter = fake_venv(tmp.path(), ".venv with spaces 'quoted'").to_string_lossy().into_owned();
+    let bin = tmp.path().join(".venv with spaces 'quoted'").join(bin_dir());
+    for (shell, script, powershell) in [
+        (r"C:\Program Files\PowerShell\7\pwsh.exe", "Activate.ps1", true),
+        (r"C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe", "Activate.ps1", true),
+        (r"C:\Windows\System32\cmd.exe", "activate.bat", false),
+    ] {
+        assert_eq!(terminal_activation(tmp.path(), &s, shell), None, "missing {script}");
+        let path = bin.join(script);
+        std::fs::write(&path, "").unwrap();
+        let expected = if powershell {
+            format!("& '{}'", path.to_string_lossy().replace('\'', "''"))
+        } else {
+            format!("\"{}\"", path.display())
+        };
+        assert_eq!(terminal_activation(tmp.path(), &s, shell), Some(expected), "{shell}");
+        std::fs::remove_file(path).unwrap();
+    }
+    assert_eq!(terminal_activation(tmp.path(), &s, ""), None);
+    assert_eq!(terminal_activation(tmp.path(), &s, "   "), None);
 }

 #[test]
@@ -514,12 +540,12 @@ fn build_dependencies_resolve_to_local_jars() {
        std::fs::write(&p, "").unwrap();
        p
    };
-    touch(m2.join("com/google/guava/guava/33.0/guava-33.0.jar"));
-    let guava_src = touch(m2.join("com/google/guava/guava/33.0/guava-33.0-sources.jar"));
+    let guava = touch(m2.join("com/google/guava/guava/33.0/guava-33.0.jar"));
+    touch(m2.join("com/google/guava/guava/33.0/guava-33.0-sources.jar"));
    let junit = touch(m2.join("junit/junit/4.13/junit-4.13.jar"));
    let files = gradle.join("caches/modules-2/files-2.1/org.slf4j/slf4j-api/2.0.9");
-    touch(files.join("a1b2/slf4j-api-2.0.9.jar"));
-    let slf4j_src = touch(files.join("c3d4/slf4j-api-2.0.9-sources.jar"));
+    let slf4j = touch(files.join("a1b2/slf4j-api-2.0.9.jar"));
+    touch(files.join("c3d4/slf4j-api-2.0.9-sources.jar"));
    let dep = |gradle: bool, g: &str, a: &str, v: &str| BuildDependency {
        gradle,
        group: g.into(),
@@ -540,14 +566,14 @@ fn build_dependencies_resolve_to_local_jars() {
    assert_eq!(
        shown,
        [
-            ("Maven: com.google.guava:guava:33.0", "maven", "guava-33.0-sources.jar"),
+            ("Maven: com.google.guava:guava:33.0", "maven", "guava-33.0.jar"),
            ("Maven: junit:junit:4.13", "maven", "junit-4.13.jar"),
-            ("Gradle: org.slf4j:slf4j-api:2.0.9", "gradle", "slf4j-api-2.0.9-sources.jar"),
+            ("Gradle: org.slf4j:slf4j-api:2.0.9", "gradle", "slf4j-api-2.0.9.jar"),
        ]
    );
-    assert_eq!(groups[0].roots[0].path, ide_core::IpcPath::from(ide_vfs::archive_root(&guava_src)));
+    assert_eq!(groups[0].roots[0].path, ide_core::IpcPath::from(ide_vfs::archive_root(&guava)));
    assert_eq!(groups[1].roots[0].path, ide_core::IpcPath::from(ide_vfs::archive_root(&junit)));
-    assert_eq!(groups[2].roots[0].path, ide_core::IpcPath::from(ide_vfs::archive_root(&slf4j_src)));
+    assert_eq!(groups[2].roots[0].path, ide_core::IpcPath::from(ide_vfs::archive_root(&slf4j)));
    // A Gradle build also finds jars installed in the Maven local repository (`mavenLocal()`).
    let groups = dependency_libraries(&[dep(true, "junit", "junit", "4.13")], Some(&m2), Some(&gradle));
    assert_eq!(groups[0].name, "Gradle: junit:junit:4.13");
@@ -1,6 +1,6 @@
 //! Filesystem operations shared by deployment and remote development bootstrap.
 use crate::sftp::{RemoteEntry, SftpFs};
-use ide_core::{IdeError, IdeResult};
+use ide_core::{CancellationToken, IdeError, IdeResult};
 use russh_sftp::client::SftpSession;
 use serde::{Deserialize, Serialize};
 use specta::Type;
@@ -115,6 +115,50 @@ impl RemoteFs {
        }
    }

+    /// Exclusive creation keeps imports from overwriting a concurrent copy.
+    pub async fn upload_new(&self, local: &Path, remote: &str, cancel: &CancellationToken) -> IdeResult<()> {
+        if cancel.is_cancelled() {
+            return Err(IdeError::cancelled());
+        }
+        match self {
+            Self::Sftp(fs) => fs.upload_new(local, remote, cancel).await,
+            Self::Local => {
+                let mut input = tokio::fs::File::open(local).await?;
+                let mut output = tokio::fs::OpenOptions::new().write(true).create_new(true).open(remote).await?;
+                let result = async {
+                    copy_stream(&mut input, &mut output, cancel).await?;
+                    #[cfg(unix)]
+                    output.set_permissions(input.metadata().await?.permissions()).await?;
+                    Ok(())
+                }
+                .await;
+                drop(output);
+                if result.is_err() {
+                    let _ = tokio::fs::remove_file(remote).await;
+                }
+                result
+            }
+        }
+    }
+
+    /// Creates the link itself, preserving a relative or dangling target.
+    pub async fn symlink(&self, target: &str, link: &str) -> IdeResult<()> {
+        match self {
+            Self::Sftp(fs) => fs.symlink(target, link).await,
+            #[cfg(unix)]
+            Self::Local => Ok(tokio::fs::symlink(target, link).await?),
+            #[cfg(not(unix))]
+            Self::Local => Err(IdeError::invalid("Cannot create a symbolic link on this client")),
+        }
+    }
+
+    pub async fn create_dir(&self, path: &str) -> IdeResult<()> {
+        match self {
+            Self::Sftp(fs) => fs.create_dir(path).await,
+            Self::Local => Ok(tokio::fs::create_dir(path).await?),
+        }
+    }
+
    pub async fn download(&self, remote: &str, local: &Path) -> IdeResult<()> {
        match self {
            Self::Sftp(fs) => fs.download(remote, local).await,
@@ -199,6 +243,28 @@ impl RemoteFs {
    }
 }

+pub(crate) async fn copy_stream(
+    input: &mut (impl tokio::io::AsyncRead + Unpin),
+    output: &mut (impl tokio::io::AsyncWrite + Unpin),
+    cancel: &CancellationToken,
+) -> IdeResult<()> {
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+    tokio::select! {
+        biased;
+        _ = cancel.cancelled() => Err(IdeError::cancelled()),
+        result = async {
+            let mut buf = vec![0; 64 * 1024];
+            loop {
+                let len = input.read(&mut buf).await?;
+                if len == 0 { break; }
+                output.write_all(&buf[..len]).await?;
+            }
+            output.flush().await?;
+            Ok(())
+        } => result,
+    }
+}
+
 /// Copies without holding the file in memory: deployments can include large archives.
 async fn copy_file(from: &Path, to: &Path) -> IdeResult<()> {
    if let Some(parent) = to.parent() {
@@ -1,9 +1,9 @@
 //! Remote files over SFTP. Remote paths are POSIX strings.

-use ide_core::{IdeError, IdeResult, error::ErrorKind};
+use ide_core::{CancellationToken, IdeError, IdeResult, error::ErrorKind};
 use russh_sftp::client::SftpSession;
 use russh_sftp::client::error::Error as SftpError;
-use russh_sftp::protocol::{FileAttributes, StatusCode};
+use russh_sftp::protocol::{FileAttributes, OpenFlags, StatusCode};
 use serde::{Deserialize, Serialize};
 use specta::Type;
 use std::path::Path;
@@ -168,6 +168,45 @@ impl SftpFs {
        self.write(remote, &data, mtime).await
    }

+    /// Imports a local file without replacing an existing remote entry.
+    pub async fn upload_new(&self, local: &Path, remote: &str, cancel: &CancellationToken) -> IdeResult<()> {
+        let mut input = tokio::fs::File::open(local).await?;
+        let mut output = self
+            .sftp
+            .open_with_flags(remote, OpenFlags::WRITE | OpenFlags::CREATE | OpenFlags::EXCLUDE)
+            .await
+            .map_err(|e| err(remote, e))?;
+        let result = crate::filesystem::copy_stream(&mut input, &mut output, cancel).await;
+        let closed = output.shutdown().await.map_err(IdeError::from);
+        drop(output);
+        let result = async {
+            result.and(closed)?;
+            #[cfg(unix)]
+            {
+                use std::os::unix::fs::PermissionsExt;
+                let mode = input.metadata().await?.permissions().mode() & 0o7777;
+                self.sftp
+                    .set_metadata(remote, FileAttributes { permissions: Some(mode), ..FileAttributes::empty() })
+                    .await
+                    .map_err(|e| err(remote, e))?;
+            }
+            Ok(())
+        }
+        .await;
+        if result.is_err() {
+            let _ = self.sftp.remove_file(remote).await;
+        }
+        result
+    }
+
+    pub async fn symlink(&self, target: &str, link: &str) -> IdeResult<()> {
+        self.sftp.symlink(target, link).await.map_err(|e| err(link, e))
+    }
+
+    pub async fn create_dir(&self, path: &str) -> IdeResult<()> {
+        self.sftp.create_dir(path).await.map_err(|e| err(path, e))
+    }
+
    pub async fn download(&self, remote: &str, local: &Path) -> IdeResult<()> {
        let data = self.read(remote).await?;
        if let Some(dir) = local.parent() {
@@ -164,6 +164,7 @@ impl russh_sftp::server::Handler for Sftp {
            .read(pflags.contains(OpenFlags::READ))
            .write(pflags.contains(OpenFlags::WRITE))
            .create(pflags.contains(OpenFlags::CREATE))
+            .create_new(pflags.contains(OpenFlags::EXCLUDE))
            .truncate(pflags.contains(OpenFlags::TRUNCATE))
            .open(path)
            .map_err(code)?;
@@ -213,6 +214,11 @@ impl russh_sftp::server::Handler for Sftp {
    }

    async fn setstat(&mut self, id: u32, path: String, attrs: FileAttributes) -> Result<Status, Self::Error> {
+        #[cfg(unix)]
+        if let Some(mode) = attrs.permissions {
+            use std::os::unix::fs::PermissionsExt;
+            std::fs::set_permissions(self.local(&path), std::fs::Permissions::from_mode(mode)).map_err(code)?;
+        }
        if let Some(t) = attrs.mtime {
            let time = std::time::UNIX_EPOCH + std::time::Duration::from_secs(t.into());
            let f = std::fs::File::options().write(true).open(self.local(&path)).map_err(code)?;
@@ -255,6 +261,12 @@ impl russh_sftp::server::Handler for Sftp {
        Ok(ok(id))
    }

+    #[cfg(unix)]
+    async fn symlink(&mut self, id: u32, target: String, link: String) -> Result<Status, Self::Error> {
+        std::os::unix::fs::symlink(target, self.local(&link)).map_err(code)?;
+        Ok(ok(id))
+    }
+
    async fn rename(&mut self, id: u32, oldpath: String, newpath: String) -> Result<Status, Self::Error> {
        std::fs::rename(self.local(&oldpath), self.local(&newpath)).map_err(code)?;
        Ok(ok(id))
@@ -497,7 +497,7 @@ pub fn available_shells() -> Vec<String> {

 /// Picks the shell binary and its arguments. A default (or explicitly chosen but
 /// argument-less) POSIX shell is started as a login shell, like Terminal.app/IDEA.
-fn resolve_shell(shell: Option<&str>, args: &[String]) -> (String, Vec<String>) {
+pub fn resolve_shell(shell: Option<&str>, args: &[String]) -> (String, Vec<String>) {
    let shell = shell.map(str::trim).filter(|s| !s.is_empty()).map(str::to_owned).unwrap_or_else(default_shell);
    if !args.is_empty() {
        return (shell, args.to_vec());
@@ -808,8 +808,12 @@ mod tests {
        assert_eq!((shell.as_str(), args), ("/bin/zsh", vec!["-l".to_owned()]));
        let (_, args) = resolve_shell(Some("/usr/bin/python3"), &[]);
        assert!(args.is_empty());
-        let (_, args) = resolve_shell(None, &[]);
-        assert_eq!(args, vec!["-l".to_owned()]);
+        for configured in [None, Some(""), Some(" \t ")] {
+            let (shell, args) = resolve_shell(configured, &[]);
+            assert_eq!(shell, default_shell_path());
+            assert_eq!(args, vec!["-l".to_owned()]);
+        }
+        assert_eq!(resolve_shell(Some(" /bin/bash "), &["-i".into()]), ("/bin/bash".into(), vec!["-i".into()]));
        assert_eq!(shell_title("C:\\Program Files\\PowerShell\\7\\pwsh.exe"), "pwsh");
        let env = terminal_env(&BTreeMap::from([("TERM".into(), "dumb".into())]));
        assert_eq!(env["TERM"], "dumb");
@@ -0,0 +1,28 @@
+//! Versioned app-owned plugin jars, shared by tool detection and language-server launches.
+
+use crate::{Method, ToolSpec};
+use std::path::{Path, PathBuf};
+
+pub(crate) fn install(root: &Path, spec: &ToolSpec) -> std::io::Result<PathBuf> {
+    let Method::Bundled { filename, bytes, .. } = spec.method else { unreachable!("bundled tool") };
+    let dir = root.join(spec.name).join("bin");
+    // The agent path participates in the JDT LS workspace key: upgrades must
+    // discard incremental state compiled with the previous agent.
+    let path = dir.join(filename);
+    if std::fs::read(&path).is_ok_and(|old| old == bytes) {
+        return Ok(path);
+    }
+    std::fs::create_dir_all(&dir)?;
+    let nonce = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap_or_default().as_nanos();
+    let temporary = dir.join(format!(".{filename}-{}-{nonce}.tmp", std::process::id()));
+    let result = std::fs::write(&temporary, bytes).and_then(|_| std::fs::rename(&temporary, &path));
+    if let Err(error) = result {
+        let _ = std::fs::remove_file(&temporary);
+        // Another window may have installed the same bytes concurrently.
+        if !std::fs::read(&path).is_ok_and(|old| old == bytes) {
+            tracing::warn!(tool = spec.name, %error, "Bundled plugin unavailable");
+            return Err(error);
+        }
+    }
+    Ok(path)
+}
@@ -0,0 +1,174 @@
+//! External formatting: resolve a tool, pass unsaved text on stdin, return text without writing files.
+
+use crate::Tools;
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use ide_language::FormatterConfig;
+use std::ffi::OsString;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+use std::time::Duration;
+
+/// Walk from the file's directory upward, including workspace parents (monorepos).
+pub fn find_up(file: &Path, relative: &Path) -> Option<PathBuf> {
+    file.parent()?.ancestors().map(|dir| dir.join(relative)).find(|p| p.is_file())
+}
+
+fn package_bin(package: &Path) -> IdeResult<PathBuf> {
+    let json: serde_json::Value = serde_json::from_slice(&std::fs::read(package.join("package.json"))?)
+        .map_err(|e| IdeError::invalid(format!("Prettier: {e}")))?;
+    let bin = json["bin"]
+        .as_str()
+        .or_else(|| json["bin"]["prettier"].as_str())
+        .ok_or_else(|| IdeError::invalid("Prettier: package has no CLI entry point"))?;
+    let path = package.join(bin);
+    if !path.is_file() {
+        return Err(IdeError::unavailable(format!("Prettier: CLI does not exist: {}", path.display())));
+    }
+    Ok(path)
+}
+
+impl Tools {
+    /// Explicit executable/script, then the nearest project package, then managed tools and PATH.
+    pub fn formatter_command(&self, tool: &str, file: &Path, custom: Option<&Path>) -> IdeResult<Command> {
+        self.resolve_formatter_command(tool, file, custom).map_err(|e| e.with_tool(tool))
+    }
+
+    fn resolve_formatter_command(&self, tool: &str, file: &Path, custom: Option<&Path>) -> IdeResult<Command> {
+        if tool != "prettier" {
+            return Err(IdeError::unavailable(format!("Unknown external formatter: {tool}")));
+        }
+        let (path, node) = if let Some(custom) = custom.filter(|p| p.is_dir()) {
+            (package_bin(custom)?, true)
+        } else if let Some(custom) = custom {
+            (custom.to_path_buf(), matches!(custom.extension().and_then(|s| s.to_str()), Some("js" | "cjs" | "mjs")))
+        } else if let Some(manifest) = find_up(file, Path::new("node_modules/prettier/package.json")) {
+            (package_bin(manifest.parent().unwrap())?, true)
+        } else if self.root.join("node_modules/prettier/package.json").is_file() {
+            (package_bin(&self.root.join("node_modules/prettier"))?, true)
+        } else {
+            (self.which("prettier").ok_or_else(|| IdeError::missing_tool("prettier"))?, false)
+        };
+        if node {
+            let node = self.which("node").ok_or_else(|| IdeError::unavailable("Prettier: Node.js is required"))?;
+            let mut cmd = self.command(node);
+            cmd.arg(path);
+            Ok(cmd)
+        } else {
+            Ok(self.command(path))
+        }
+    }
+}
+
+/// Project configuration overrides these defaults; Prettier resolves config and plugins itself.
+pub fn arguments(
+    config: &FormatterConfig,
+    file: &Path,
+    tab_size: u32,
+    insert_spaces: bool,
+    range: Option<(u32, u32)>,
+) -> Vec<OsString> {
+    let parser = if config.parser == "markdown" && file.extension().is_some_and(|s| s == "mdx") {
+        "mdx"
+    } else {
+        &config.parser
+    };
+    let mut args: Vec<OsString> = [
+        "--parser",
+        parser,
+        "--config-precedence",
+        "file-override",
+        "--tab-width",
+        &tab_size.max(1).to_string(),
+        "--use-tabs",
+        if insert_spaces { "false" } else { "true" },
+    ]
+    .into_iter()
+    .map(Into::into)
+    .collect();
+    args.extend(["--stdin-filepath".into(), file.as_os_str().to_owned()]);
+    if config.range
+        && let Some((start, end)) = range
+    {
+        args.extend(["--range-start".into(), start.to_string().into(), "--range-end".into(), end.to_string().into()]);
+    }
+    // CLI defaults only find ignores in cwd; explicitly pass the nearest ancestor's files.
+    for name in [".prettierignore", ".gitignore"] {
+        if let Some(path) = find_up(file, Path::new(name)) {
+            args.extend(["--ignore-path".into(), path.into_os_string()]);
+        }
+    }
+    args
+}
+
+pub fn run(mut command: Command, text: &str, cancel: &CancellationToken) -> IdeResult<String> {
+    crate::process::run_input(&mut command, text, Duration::from_secs(15), cancel).map_err(|e| e.with_tool("prettier"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn missing_formatter_is_structured_but_invalid_custom_path_is_not_an_install_prompt() {
+        use ide_core::error::{ErrorData, ErrorKind};
+        let dir = tempfile::tempdir().unwrap();
+        let tools = Tools::with_paths(dir.path().join("tools"), OsString::new(), crate::platform::Platform::current());
+        let file = dir.path().join("file.md");
+        let missing = tools.formatter_command("prettier", &file, None).unwrap_err();
+        assert_eq!(missing.kind, ErrorKind::NotFound);
+        assert_eq!(missing.data, Some(ErrorData::Tool { tool: "prettier".into(), missing: true }));
+        let custom = tools.formatter_command("prettier", &file, Some(&dir.path().join("absent-prettier"))).unwrap();
+        let failure = run(custom, "text", &Default::default()).unwrap_err();
+        assert_eq!(failure.data, Some(ErrorData::Tool { tool: "prettier".into(), missing: false }));
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn stderr_is_preserved_verbatim_even_when_longer_than_four_thousand_characters() {
+        let mut command = Command::new("sh");
+        command.args(["-c", "i=0; while [ $i -lt 1000 ]; do printf 'error\\n' >&2; i=$((i+1)); done; exit 1"]);
+        let failure = run(command, "", &Default::default()).unwrap_err();
+        assert_eq!(failure.message, "error\n".repeat(1000));
+        assert_eq!(failure.data, Some(ide_core::error::ErrorData::Tool { tool: "prettier".into(), missing: false }));
+    }
+
+    #[test]
+    fn discovers_nearest_package_and_ignore_above_nested_file() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        std::fs::create_dir_all(root.join("packages/web/src")).unwrap();
+        std::fs::write(root.join(".prettierignore"), "ignored.md").unwrap();
+        std::fs::create_dir_all(root.join("node_modules/prettier")).unwrap();
+        std::fs::write(root.join("node_modules/prettier/package.json"), "{}").unwrap();
+        let file = root.join("packages/web/src/readme.md");
+        assert_eq!(find_up(&file, Path::new(".prettierignore")), Some(root.join(".prettierignore")));
+        std::fs::write(root.join("packages/web/.prettierignore"), "src/ignored.md").unwrap();
+        assert_eq!(find_up(&file, Path::new(".prettierignore")), Some(root.join("packages/web/.prettierignore")));
+        assert_eq!(
+            find_up(&file, Path::new("node_modules/prettier/package.json")),
+            Some(root.join("node_modules/prettier/package.json"))
+        );
+    }
+
+    #[test]
+    fn arguments_use_stdin_config_precedence_and_only_supported_ranges() {
+        for (parser, supports_range) in [
+            ("markdown", false),
+            ("css", false),
+            ("yaml", false),
+            ("typescript", true),
+            ("graphql", true),
+            ("vue", true),
+        ] {
+            let config = FormatterConfig { tool: "prettier".into(), parser: parser.into(), range: supports_range };
+            let args = arguments(&config, Path::new("/project with spaces/file.md"), 4, false, Some((3, 9)));
+            let args: Vec<_> = args.iter().map(|a| a.to_string_lossy()).collect();
+            assert!(args.windows(2).any(|a| a == ["--config-precedence", "file-override"]));
+            assert!(args.windows(2).any(|a| a == ["--stdin-filepath", "/project with spaces/file.md"]));
+            assert!(args.windows(2).any(|a| a == ["--tab-width", "4"]));
+            assert!(args.windows(2).any(|a| a == ["--use-tabs", "true"]));
+            assert_eq!(args.contains(&"--range-start".into()), supports_range);
+            assert!(!args.contains(&"--write".into()));
+        }
+    }
+}
@@ -10,6 +10,8 @@
 //! [`tools_bin_dirs`] on the process `PATH` at startup.

 pub mod archive;
+mod bundled;
+pub mod formatter;
 pub mod jdk;
 pub mod platform;
 mod process;
@@ -146,7 +148,7 @@ fn managed_bin_dir(root: &Path, spec: &ToolSpec, platform: Platform) -> Option<P
        Method::PipVenv { .. } => {
            Some(root.join(spec.name).join("venv").join(if platform.os == Os::Windows { "Scripts" } else { "bin" }))
        }
-        Method::Rustup { .. } | Method::PipUser { .. } | Method::PipTarget { .. } => None,
+        Method::Bundled { .. } | Method::Rustup { .. } | Method::PipUser { .. } | Method::PipTarget { .. } => None,
    }
 }

@@ -322,6 +324,9 @@ fn usages(langs: &[LanguageConfig]) -> BTreeMap<String, Usage> {
        }
    };
    for l in langs {
+        if let Some(f) = &l.formatter {
+            add(&f.tool, &f.tool, ToolKind::Formatter, None, &l.name);
+        }
        for s in &l.language_servers {
            add(&s.name, &s.command, ToolKind::LanguageServer, s.install_hint.as_ref(), &l.name);
        }
@@ -389,9 +394,12 @@ fn is_bundle(command: &str) -> bool {
    command.ends_with(".jar")
 }

-/// Path of an installed plugin bundle (`<tools>/<name>/bin/<jar>`), if present.
+/// Path of an app-provided or installed plugin jar. Embedded jars are materialized on demand.
 pub fn managed_bundle(app_data: &Path, name: &str) -> Option<PathBuf> {
    let spec = registry::find(name)?;
+    if matches!(spec.method, Method::Bundled { .. }) {
+        return bundled::install(&tools_dir(app_data), spec).ok();
+    }
    let jar = spec.commands.first().filter(|c| is_bundle(c))?;
    let path = tools_dir(app_data).join(spec.name).join("bin").join(jar);
    path.is_file().then_some(path)
@@ -542,6 +550,7 @@ impl Tools {
    fn method_missing(&self, method: Method) -> Option<String> {
        let need = |ok: bool, msg: &str| (!ok).then(|| msg.to_string());
        match method {
+            Method::Bundled { .. } => None,
            Method::Rustup { .. } => need(self.which("rustup").is_some(), "rustup is required (https://rustup.rs)"),
            Method::Npm { .. } => need(
                self.which_any(&["npm", "pnpm"]).is_some(),
@@ -604,7 +613,8 @@ impl Tools {
        };
        let (status, path, version) = self.detect(spec);
        let unavailable_reason = self.unavailable_reason(spec);
-        let can_uninstall = status == ToolStatus::Installed;
+        let bundled = matches!(spec.method, Method::Bundled { .. });
+        let can_uninstall = status == ToolStatus::Installed && !bundled;
        Some(ToolInfo {
            name: spec.name.to_string(),
            display_name: spec.display.to_string(),
@@ -615,7 +625,7 @@ impl Tools {
            path: path.map(Into::into),
            version,
            install_method: Some(self.install_method(spec).label().to_string()),
-            can_install: unavailable_reason.is_none(),
+            can_install: unavailable_reason.is_none() && !bundled,
            unavailable_reason,
            can_uninstall,
            install_hint,
@@ -654,6 +664,12 @@ impl Tools {
    }

    fn detect(&self, spec: &ToolSpec) -> (ToolStatus, Option<PathBuf>, Option<String>) {
+        if let Method::Bundled { version, .. } = spec.method {
+            return match bundled::install(&self.root, spec) {
+                Ok(path) => (ToolStatus::Installed, Some(path), Some(version.to_owned())),
+                Err(_) => (ToolStatus::Missing, None, None),
+            };
+        }
        let main = spec.commands[0];
        let managed = managed_bin_dir(&self.root, spec, self.platform).and_then(|d| self.exe_in(&d, main));
        if let Some(path) = managed {
@@ -782,6 +798,9 @@ impl Tools {
            let method = self.install_method(spec);
            emit(InstallEvent::Line { text: format!("Installing {} via {}…", spec.display, method.label()) });
            match method {
+                Method::Bundled { .. } => {
+                    bundled::install(&self.root, spec)?;
+                }
                Method::Rustup { component } => {
                    let mut c = self.command(self.which("rustup").expect("checked"));
                    c.args(["component", "add", component]);
@@ -1188,6 +1207,8 @@ impl Tools {
        let cancel = CancellationToken::new();
        let quiet = |_: InstallEvent| {};
        match self.install_method(spec) {
+            // App-owned resources remain available for every project/window.
+            Method::Bundled { .. } => {}
            Method::Rustup { component } => {
                let rustup = self.which("rustup").ok_or_else(|| IdeError::unavailable("rustup not found"))?;
                let mut c = self.command(rustup);
@@ -348,6 +348,89 @@ pub fn progress_event(bytes: u64, size: Option<u64>) -> InstallEvent {
    }
 }

+/// Runs a formatter with separate pipes so diagnostics can never become document text.
+pub(crate) fn run_input(
+    cmd: &mut Command,
+    input: &str,
+    timeout: Duration,
+    cancel: &CancellationToken,
+) -> IdeResult<String> {
+    use std::io::Write;
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    let mut child = own_group(cmd).stdin(Stdio::piped()).stdout(Stdio::piped()).stderr(Stdio::piped()).spawn()?;
+    let mut stdin = child.stdin.take().unwrap();
+    let input = input.to_owned();
+    // All pipes drain concurrently, including stdin: large documents cannot deadlock or bypass the timeout.
+    enum Pipe {
+        Written(std::io::Result<()>),
+        Read(bool, std::io::Result<Vec<u8>>),
+    }
+    let (tx, rx) = mpsc::channel();
+    let writer = tx.clone();
+    std::thread::spawn(move || {
+        let _ = writer.send(Pipe::Written(stdin.write_all(input.as_bytes())));
+    });
+    for (is_stderr, mut pipe) in [
+        (false, Box::new(child.stdout.take().unwrap()) as Box<dyn Read + Send>),
+        (true, Box::new(child.stderr.take().unwrap()) as Box<dyn Read + Send>),
+    ] {
+        let tx = tx.clone();
+        std::thread::spawn(move || {
+            let mut bytes = Vec::new();
+            let _ = tx.send(Pipe::Read(is_stderr, pipe.read_to_end(&mut bytes).map(|_| bytes)));
+        });
+    }
+    drop(tx);
+    let started = Instant::now();
+    let (mut status, mut output, mut errors, mut written) = (None, None, None, None);
+    let result = loop {
+        if cancel.is_cancelled() {
+            break Err(IdeError::cancelled());
+        }
+        if started.elapsed() >= timeout {
+            break Err(IdeError::new(ErrorKind::TimedOut, "Formatting timed out"));
+        }
+        if status.is_none() {
+            match child.try_wait() {
+                Ok(s) => status = s,
+                Err(e) => break Err(e.into()),
+            }
+        }
+        if status.is_some() && output.is_some() && errors.is_some() && written.is_some() {
+            break Ok(());
+        }
+        match rx.recv_timeout(Duration::from_millis(10)) {
+            Ok(Pipe::Written(result)) => written = Some(result),
+            Ok(Pipe::Read(true, result)) => errors = Some(result),
+            Ok(Pipe::Read(false, result)) => output = Some(result),
+            Err(mpsc::RecvTimeoutError::Disconnected) if output.is_some() && errors.is_some() && written.is_some() => {
+                std::thread::sleep(Duration::from_millis(10));
+            }
+            Err(mpsc::RecvTimeoutError::Disconnected) => break Err(IdeError::internal("formatter pipe reader failed")),
+            Err(mpsc::RecvTimeoutError::Timeout) => {}
+        }
+    };
+    if result.is_err() {
+        kill(&mut child);
+    }
+    result?;
+    let output = output.unwrap()?;
+    let errors = errors.unwrap()?;
+    let status = status.unwrap();
+    if !status.success() {
+        let diagnostics: String = String::from_utf8_lossy(&errors).into_owned();
+        return Err(IdeError::invalid(if diagnostics.trim().is_empty() {
+            format!("Formatter exited with {status}")
+        } else {
+            diagnostics
+        }));
+    }
+    written.unwrap()?;
+    String::from_utf8(output).map_err(|e| IdeError::invalid(e.to_string()))
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -464,3 +547,37 @@ mod tests {
        assert_eq!(run_quiet(cmd, Duration::from_secs(5)), Some((true, "v1.2.3\n".into())));
    }
 }
+
+#[cfg(all(test, unix))]
+mod input_tests {
+    use super::*;
+
+    #[test]
+    fn separate_diagnostics_and_never_return_failed_output() {
+        let mut command = Command::new("sh");
+        command.args(["-c", "cat; printf warning >&2"]);
+        assert_eq!(run_input(&mut command, "a😀\n", Duration::from_secs(2), &Default::default()).unwrap(), "a😀\n");
+        let mut command = Command::new("sh");
+        command.args(["-c", "printf broken; printf 'invalid syntax' >&2; exit 1"]);
+        let e = run_input(&mut command, "", Duration::from_secs(2), &Default::default()).unwrap_err();
+        assert_eq!(e.message, "invalid syntax");
+    }
+
+    #[test]
+    fn timeout_kills_formatter_and_cancellation_prevents_start() {
+        let mut command = Command::new("sh");
+        command.args(["-c", "sleep 10 &"]);
+        let start = Instant::now();
+        assert_eq!(
+            run_input(&mut command, "", Duration::from_millis(50), &Default::default()).unwrap_err().kind,
+            ErrorKind::TimedOut
+        );
+        assert!(start.elapsed() < Duration::from_secs(2));
+        let cancel = CancellationToken::new();
+        cancel.cancel();
+        assert_eq!(
+            run_input(&mut Command::new("does-not-exist"), "", Duration::from_secs(2), &cancel).unwrap_err().kind,
+            ErrorKind::Cancelled
+        );
+    }
+}
@@ -12,6 +12,7 @@ pub enum ToolKind {
    Debugger,
    /// Loaded into another tool's process, e.g. a jdtls agent.
    Plugin,
+    Formatter,
 }

 /// Where release archives come from.
@@ -31,6 +32,8 @@ pub enum ReleaseSource {

 #[derive(Clone, Copy, Debug)]
 pub enum Method {
+    /// An app-owned plugin jar, materialized without a network download.
+    Bundled { filename: &'static str, version: &'static str, bytes: &'static [u8] },
    /// `rustup component add <component>`.
    Rustup { component: &'static str },
    /// npm / pnpm packages installed into `<tools>/node_modules`; the first is the primary one.
@@ -56,6 +59,7 @@ pub enum Method {
 impl Method {
    pub fn label(&self) -> &'static str {
        match self {
+            Method::Bundled { .. } => "Bundled",
            Method::Rustup { .. } => "rustup",
            Method::Npm { .. } => "npm",
            Method::Go { .. } => "go install",
@@ -102,7 +106,7 @@ impl ToolSpec {

 use Arch::{Arm64, X64};
 use Os::{Linux, Mac, Windows};
-use ToolKind::{Debugger, LanguageServer, Plugin};
+use ToolKind::{Debugger, Formatter, LanguageServer, Plugin};

 const V: Option<(&str, &[&str])> = None;
 const JAVA: &[(&str, &str)] = &[("java", "Java is required (https://adoptium.net)")];
@@ -119,6 +123,17 @@ const fn ver(cmd: &'static str) -> Option<(&'static str, &'static [&'static str]
 pub const TYPESCRIPT: &str = "typescript@6";

 pub static TOOLS: &[ToolSpec] = &[
+    ToolSpec {
+        name: "prettier",
+        display: "Prettier",
+        kind: Formatter,
+        commands: &["prettier"],
+        method: Method::Npm { packages: &["prettier"] },
+        fallback: None,
+        version: ver("prettier"),
+        needs: NODE,
+        homepage: "https://prettier.io",
+    },
    ToolSpec {
        name: "rust-analyzer",
        display: "rust-analyzer",
@@ -578,15 +593,13 @@ pub static TOOLS: &[ToolSpec] = &[
        display: "Lombok (jdtls agent)",
        kind: Plugin,
        commands: &["lombok.jar"],
-        // Newer than the Lombok a project pins: old ones fail inside current ECJ.
-        method: Method::Release {
-            source: ReleaseSource::MavenCentral { group: "org.projectlombok", artifact: "lombok" },
-            assets: &[
-                any_arch(Mac, "lombok-*.jar"),
-                any_arch(Linux, "lombok-*.jar"),
-                any_arch(Windows, "lombok-*.jar"),
-            ],
-            locate: &["lombok.jar"],
+        // Equinox removed getModuleClassLoader(boolean), breaking lombok.config lookup.
+        // Return to Maven Central once an official release includes lombok#4059.
+        // Source commit, build instructions and checksum: plugins/lombok/README.md.
+        method: Method::Bundled {
+            filename: "lombok-1.18.48-openidea.1.jar",
+            version: "1.18.48-openidea.1",
+            bytes: include_bytes!("../../../plugins/lombok/lombok-1.18.48-openidea.1.jar"),
        },
        fallback: None,
        version: V,
@@ -942,6 +955,11 @@ mod tests {
                known.insert((d.adapter.clone(), d.command.clone()));
            }
        }
+        for l in &langs {
+            if let Some(f) = &l.formatter {
+                known.insert((f.tool.clone(), f.tool.clone()));
+            }
+        }
        for t in TOOLS.iter().filter(|t| t.kind != Plugin) {
            assert!(
                known.contains(&(t.name.to_string(), t.commands[0].to_string())),
@@ -434,7 +434,6 @@ mod tests {
        assert_eq!(d.version, "1.18.48");
        assert_eq!(d.name, "lombok-1.18.48.jar");
        assert_eq!(d.url, "https://repo1.maven.org/maven2/org/projectlombok/lombok/1.18.48/lombok-1.18.48.jar");
-        assert!(select_asset(&[d.name.as_str()], find("lombok").unwrap().asset_rules(), LINUX).is_some());
        assert!(maven_pick("g", "a", "<metadata/>").is_err());
        assert!(maven_pick("g", "a", "<release>../x</release>").is_err());
    }
@@ -43,6 +43,61 @@ fn find<'a>(list: &'a [ToolInfo], name: &str) -> &'a ToolInfo {
    list.iter().find(|t| t.name == name).unwrap_or_else(|| panic!("{name} not listed"))
 }

+#[test]
+fn bundled_lombok_replaces_legacy_installs_on_every_platform_without_downloads() {
+    for os in [Os::Mac, Os::Linux, Os::Windows] {
+        for arch in [platform::Arch::Arm64, platform::Arch::X64] {
+            let env = Env::new();
+            let legacy = env.root.join("lombok/bin/lombok.jar");
+            fs::create_dir_all(legacy.parent().unwrap()).unwrap();
+            fs::write(&legacy, b"old official agent").unwrap();
+            fs::write(env.root.join("lombok").join(MANIFEST), r#"{"version":"1.18.48"}"#).unwrap();
+            let tools = Tools::with_paths(env.root.clone(), OsString::new(), Platform { os, arch });
+            let info = tools.info("lombok", &[]).unwrap();
+            let path = managed_bundle(env.root.parent().unwrap(), "lombok").unwrap();
+            assert_eq!(info.status, ToolStatus::Installed);
+            assert_eq!(info.version.as_deref(), Some("1.18.48-openidea.1"));
+            assert_eq!(info.path, Some(path.clone().into()));
+            assert_eq!(path.file_name().unwrap(), "lombok-1.18.48-openidea.1.jar");
+            assert!(!info.can_install && !info.can_uninstall);
+            assert_eq!(tools.unavailable_reason(registry::find("lombok").unwrap()), None);
+            assert_eq!(fs::read(&legacy).unwrap(), b"old official agent", "other windows may still use it");
+        }
+    }
+}
+
+#[test]
+fn bundled_lombok_is_available_offline_and_repairs_missing_or_corrupt_files() {
+    let env = Env::new();
+    let data = env.root.parent().unwrap();
+    let agent = managed_bundle(data, "lombok").unwrap();
+    let checksum = include_str!("../../../plugins/lombok/SHA256SUMS").split_whitespace().next().unwrap();
+    assert_eq!(sources::sha256_file(&agent).unwrap(), checksum);
+    for contents in [None, Some(b"incomplete jar".as_slice())] {
+        if let Some(contents) = contents {
+            fs::write(&agent, contents).unwrap();
+        } else {
+            fs::remove_file(&agent).unwrap();
+        }
+        assert_eq!(managed_bundle(data, "lombok"), Some(agent.clone()));
+        assert_eq!(sources::sha256_file(&agent).unwrap(), checksum);
+    }
+    assert_eq!(fs::read_dir(agent.parent().unwrap()).unwrap().count(), 1, "no temporary jars left behind");
+}
+
+#[test]
+fn concurrent_windows_get_the_same_complete_bundled_lombok() {
+    let env = Env::new();
+    let data = env.root.parent().unwrap();
+    std::thread::scope(|scope| {
+        let windows: Vec<_> = (0..8).map(|_| scope.spawn(|| managed_bundle(data, "lombok").unwrap())).collect();
+        let paths: Vec<_> = windows.into_iter().map(|window| window.join().unwrap()).collect();
+        assert!(paths.iter().all(|path| path == &paths[0]));
+        let checksum = include_str!("../../../plugins/lombok/SHA256SUMS").split_whitespace().next().unwrap();
+        assert_eq!(sources::sha256_file(&paths[0]).unwrap(), checksum);
+    });
+}
+
 #[test]
 fn version_parsing() {
    assert_eq!(parse_version("rust-analyzer 1.85.0 (4d91de4e 2025-02-17)").as_deref(), Some("1.85.0"));
@@ -0,0 +1,91 @@
+//! `cargo test -p ide-tools --test prettier -- --ignored --nocapture`
+//! Installs into a temporary managed-tools directory; no repository dependency is added.
+use ide_core::CancellationToken;
+use ide_language::FormatterConfig;
+use ide_tools::{Tools, formatter};
+use std::path::Path;
+
+fn format(
+    tools: &Tools,
+    path: &Path,
+    parser: &str,
+    text: &str,
+    range: Option<(u32, u32)>,
+) -> ide_core::IdeResult<String> {
+    let config = FormatterConfig {
+        tool: "prettier".into(),
+        parser: parser.into(),
+        range: matches!(parser, "typescript" | "json" | "graphql"),
+    };
+    let mut cmd = tools.formatter_command("prettier", path, None)?;
+    cmd.current_dir(path.parent().unwrap());
+    cmd.args(formatter::arguments(&config, path, 4, true, range));
+    formatter::run(cmd, text, &CancellationToken::new())
+}
+
+#[test]
+#[ignore = "requires Node.js/npm and network; installs real Prettier into a temporary managed directory"]
+fn real_prettier_config_ignore_languages_ranges_and_errors() {
+    if std::env::var_os("OPENIDEA_TEST_OFFLINE").is_some() {
+        eprintln!("SKIP real Prettier: OPENIDEA_TEST_OFFLINE is set; npm network access is disabled");
+        return;
+    }
+    let temp = tempfile::tempdir().unwrap();
+    let tools = Tools::new(&temp.path().join("app-data"));
+    let info = tools.info("prettier", &[]).unwrap();
+    if !info.can_install {
+        eprintln!("SKIP real Prettier: {}", info.unavailable_reason.unwrap_or_default());
+        return;
+    }
+    tools.install("prettier", &[], &Default::default(), &|_| {}).expect(
+        "Prettier managed install failed; offline environments may set OPENIDEA_TEST_OFFLINE=1 (reported as SKIP)",
+    );
+    let project = temp.path().join("project with spaces");
+    std::fs::create_dir_all(project.join("docs/nested")).unwrap();
+    let md = project.join("docs/nested/readme.md");
+    let input = "# Title\ntext\n\n| a | b |\n|---|---|\n|1|2|\n\n- a\n - b\n";
+    let output = format(&tools, &md, "markdown", input, None).unwrap();
+    assert!(output.starts_with("# Title\n\ntext\n"), "{output}");
+    assert!(output.contains("| 1   | 2   |"), "{output}");
+    assert!(!md.exists(), "formatting must never write the file");
+    std::fs::write(project.join(".prettierrc"), r#"{"proseWrap":"always","printWidth":24,"tabWidth":2}"#).unwrap();
+    let prose =
+        "This is a long paragraph with several words that should wrap according to the project configuration.\n";
+    assert!(format(&tools, &md, "markdown", prose, None).unwrap().lines().count() > 2);
+    std::fs::write(project.join(".prettierignore"), "docs/nested/readme.md\n").unwrap();
+    assert_eq!(format(&tools, &md, "markdown", input, None).unwrap(), input);
+    std::fs::remove_file(project.join(".prettierignore")).unwrap();
+    std::fs::remove_file(project.join(".prettierrc")).unwrap();
+    assert_eq!(
+        format(&tools, &project.join("a.css"), "css", "a{color:red}", None).unwrap(),
+        "a {\n    color: red;\n}\n"
+    );
+    std::fs::write(project.join("package.json"), r#"{"prettier":{"tabWidth":3,"proseWrap":"never"}}"#).unwrap();
+    assert_eq!(
+        format(&tools, &project.join("a.css"), "css", "a{color:red}", None).unwrap(),
+        "a {\n   color: red;\n}\n"
+    );
+    assert_eq!(format(&tools, &project.join("a.yaml"), "yaml", "a: [1,2]\n", None).unwrap(), "a: [1, 2]\n");
+    let js = "const a={x:1};\nconst b={y:2};\n";
+    let formatted = format(&tools, &project.join("a.ts"), "typescript", js, Some((0, 14))).unwrap();
+    assert!(formatted.starts_with("const a = { x: 1 };"), "{formatted}");
+    assert!(formatted.contains("const b={y:2};"), "{formatted}");
+    assert!(format(&tools, &project.join("bad.css"), "css", "a {", None).is_err());
+    // Nearest project version must win over the managed install, including npm's object-style bin.
+    let package = project.join("node_modules/prettier");
+    std::fs::create_dir_all(&package).unwrap();
+    std::fs::write(package.join("package.json"), r#"{"bin":{"prettier":"cli.cjs"}}"#).unwrap();
+    std::fs::write(
+        package.join("cli.cjs"),
+        "process.stdin.resume(); process.stdin.on('end', () => process.stdout.write('project version\\n')); ",
+    )
+    .unwrap();
+    assert_eq!(format(&tools, &md, "markdown", input, None).unwrap(), "project version\n");
+    std::fs::write(package.join("cli.cjs"), "setInterval(() => {}, 1000)").unwrap();
+    let start = std::time::Instant::now();
+    assert!(format(&tools, &md, "markdown", input, None).unwrap_err().message.contains("timed out"));
+    assert!(start.elapsed() < std::time::Duration::from_secs(20));
+    eprintln!(
+        "PASS: real managed Prettier, config/ignore discovery, editor defaults, YAML/CSS/Markdown, ranges, errors, project precedence, timeout; no disk writes"
+    );
+}
@@ -348,6 +348,55 @@ fn run_raw_env_once(
    Ok(Output { stdout: out.stdout, stderr: out.stderr, code: out.status.code() })
 }

+/// Captures binary/NUL-delimited read output while allowing cancellation to kill git.
+pub(crate) fn run_cancellable(root: &Path, args: &[&str], cancel: &CancellationToken) -> IdeResult<Output> {
+    let out = run_cancellable_raw(root, args, cancel)?;
+    if out.code == Some(0) { Ok(out) } else { Err(failure(args, &out.stderr, &out.stdout, out.code)) }
+}
+
+/// Cancellable capture preserving exit codes for commands with documented non-error states.
+pub(crate) fn run_cancellable_raw(root: &Path, args: &[&str], cancel: &CancellationToken) -> IdeResult<Output> {
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    let mut cmd = command(root)?;
+    cmd.args(args).stdin(Stdio::null()).stdout(Stdio::piped()).stderr(Stdio::piped());
+    #[cfg(unix)]
+    {
+        use std::os::unix::process::CommandExt;
+        cmd.process_group(0);
+    }
+    let mut session = CommandSession::start(&mut cmd);
+    let mut child = cmd.spawn().map_err(spawn_error)?;
+    let capture = |mut pipe: Box<dyn Read + Send>| {
+        std::thread::spawn(move || {
+            let mut bytes = Vec::new();
+            pipe.read_to_end(&mut bytes).map(|_| bytes)
+        })
+    };
+    let stdout = capture(Box::new(child.stdout.take().expect("piped stdout")));
+    let stderr = capture(Box::new(child.stderr.take().expect("piped stderr")));
+    let status = loop {
+        if cancel.is_cancelled() {
+            kill(&mut child);
+            let _ = child.wait();
+            let _ = stdout.join();
+            let _ = stderr.join();
+            return Err(IdeError::cancelled());
+        }
+        if let Some(status) = child.try_wait()? {
+            break status;
+        }
+        std::thread::sleep(Duration::from_millis(20));
+    };
+    let join = |thread: std::thread::JoinHandle<std::io::Result<Vec<u8>>>| {
+        thread.join().map_err(|_| IdeError::internal("git output reader panicked"))?.map_err(IdeError::from)
+    };
+    let out = Output { stdout: join(stdout)?, stderr: join(stderr)?, code: status.code() };
+    session.finish(status.success(), &String::from_utf8_lossy(&out.stderr));
+    Ok(out)
+}
+
 /// Runs git and maps a non-zero exit status to an error carrying git's message.
 pub(crate) fn run(root: &Path, args: &[&str], stdin: Option<&[u8]>) -> IdeResult<Output> {
    let out = run_raw(root, args, stdin)?;
@@ -0,0 +1,521 @@
+//! Selection-scoped revision → working-tree comparison over the existing root registry.
+use crate::{ChangeKind, Repos, cli, ops};
+use ide_core::{CancellationToken, IdeError, IdeResult, IpcPath};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::path::{Path, PathBuf};
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct CompareScope {
+    pub repositories: Vec<IpcPath>,
+    /// Selected content outside registered repositories; workspace parents expand to their skipped children.
+    pub skipped_paths: Vec<IpcPath>,
+    pub single_file: bool,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct WorkingTreeChange {
+    pub path: String,
+    pub kind: ChangeKind,
+    pub old_path: Option<String>,
+    pub added: u32,
+    pub removed: u32,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct RepositoryComparison {
+    pub root: IpcPath,
+    /// Resolved commit, so opening a diff later uses the same left side as the listing.
+    pub revision: Option<String>,
+    pub files: Vec<WorkingTreeChange>,
+    pub error: Option<String>,
+    /// The requested revision does not resolve to a commit in this repository.
+    #[serde(default)]
+    pub missing_revision: bool,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct CompareResult {
+    pub repositories: Vec<RepositoryComparison>,
+    pub skipped_paths: Vec<IpcPath>,
+}
+
+fn normalized(path: &Path) -> PathBuf {
+    dunce::canonicalize(path).unwrap_or_else(|_| path.to_path_buf())
+}
+
+fn comparison_children(path: &Path) -> Vec<PathBuf> {
+    std::fs::read_dir(path)
+        .into_iter()
+        .flatten()
+        .flatten()
+        .filter(|entry| entry.file_name() != ".git" && entry.file_name() != ".openidea")
+        .map(|entry| entry.path())
+        .collect()
+}
+
+impl Repos {
+    pub fn compare_scope(&self, paths: &[PathBuf]) -> CompareScope {
+        let paths: Vec<_> = paths.iter().map(|p| normalized(p)).collect();
+        let repositories = self
+            .all()
+            .iter()
+            .filter(|r| {
+                let root = normalized(r.root());
+                paths.iter().any(|p| {
+                    root.starts_with(p)
+                        || self.at_root(p).or_else(|| self.for_path(p)).is_some_and(|owner| owner.root() == r.root())
+                })
+            })
+            .map(|r| IpcPath(r.root().to_path_buf()))
+            .collect();
+        let mut skipped = std::collections::BTreeSet::new();
+        for path in &paths {
+            if self.at_root(path).or_else(|| self.for_path(path)).is_some() {
+                continue;
+            }
+            if self.all().iter().any(|r| r.root().starts_with(path)) {
+                for child in comparison_children(path) {
+                    if self.has_outside_content(&child) {
+                        skipped.insert(child);
+                    }
+                }
+            } else {
+                skipped.insert(path.clone());
+            }
+        }
+        let skipped_paths = skipped
+            .into_iter()
+            .map(|mut path| {
+                if path.is_dir() {
+                    path.push("");
+                }
+                IpcPath(path)
+            })
+            .collect();
+        CompareScope { repositories, skipped_paths, single_file: paths.len() == 1 && !paths[0].is_dir() }
+    }
+
+    fn has_outside_content(&self, path: &Path) -> bool {
+        if self.at_root(path).or_else(|| self.for_path(path)).is_some() {
+            return false;
+        }
+        !self.all().iter().any(|r| r.root().starts_with(path))
+            || comparison_children(path).iter().any(|child| self.has_outside_content(child))
+    }
+
+    pub fn compare_paths(
+        &self,
+        paths: &[PathBuf],
+        revision: &str,
+        repositories: Option<&[PathBuf]>,
+        cancel: &CancellationToken,
+    ) -> IdeResult<CompareResult> {
+        if revision.trim().is_empty() || revision.starts_with('-') {
+            return Err(IdeError::invalid("invalid revision"));
+        }
+        let scope = self.compare_scope(paths);
+        let paths: Vec<_> = paths.iter().map(|p| normalized(p)).collect();
+        let mut result = CompareResult { repositories: Vec::new(), skipped_paths: scope.skipped_paths };
+        for root in scope.repositories {
+            if cancel.is_cancelled() {
+                return Err(IdeError::cancelled());
+            }
+            if repositories.is_some_and(|roots| !roots.iter().any(|r| normalized(r) == normalized(&root.0))) {
+                continue;
+            }
+            let repo = self.at_root(&root.0).expect("scope comes from registry");
+            let _scope =
+                crate::ExecutionScope::enter(repo.execution_allowed.load(std::sync::atomic::Ordering::Acquire));
+            let mut missing_revision = false;
+            let mut compare = || -> IdeResult<(String, Vec<WorkingTreeChange>)> {
+                // Worktree comparisons must not run repository-defined clean/process filters
+                // in Restricted Mode. External diff and textconv are disabled below as well.
+                let mut overrides = Vec::new();
+                if !crate::execution_allowed() {
+                    let config = cli::run_cancellable(repo.root(), &["config", "--null", "--list"], cancel)?;
+                    for record in config.stdout_str().split('\0') {
+                        let key = record.split('\n').next().unwrap_or_default();
+                        if key.starts_with("filter.")
+                            && (key.ends_with(".clean") || key.ends_with(".process") || key.ends_with(".required"))
+                        {
+                            overrides.push("-c".to_owned());
+                            overrides.push(format!("{key}={}", if key.ends_with(".required") { "false" } else { "" }));
+                        }
+                    }
+                }
+                let run = |args: &[&str]| {
+                    let mut full: Vec<&str> = overrides.iter().map(String::as_str).collect();
+                    full.extend_from_slice(args);
+                    cli::run_cancellable(repo.root(), &full, cancel)
+                };
+                // --quiet documents exit 1 for an unresolved revision; other failures keep their diagnostics.
+                let resolve_args =
+                    ["rev-parse", "--verify", "--quiet", "--end-of-options", &format!("{revision}^{{commit}}")];
+                let resolved = cli::run_cancellable_raw(repo.root(), &resolve_args, cancel)?;
+                if resolved.code != Some(0) {
+                    missing_revision = resolved.code == Some(1);
+                    return Err(cli::failure(&resolve_args, &resolved.stderr, &resolved.stdout, resolved.code));
+                }
+                let resolved = resolved.stdout_str().trim().to_owned();
+                // Disable textconv/external diff; these are also safe in untrusted projects.
+                let names =
+                    run(&["diff", "--name-status", "-z", "-M", "--no-ext-diff", "--no-textconv", &resolved, "--"])?;
+                let stats = run(&[
+                    "diff",
+                    "--numstat",
+                    "-z",
+                    "--no-renames",
+                    "--no-ext-diff",
+                    "--no-textconv",
+                    &resolved,
+                    "--",
+                ])?;
+                let stats: std::collections::HashMap<_, _> = ops::parse_numstat(&stats.stdout_str())
+                    .into_iter()
+                    .map(|(path, added, removed)| (path, (added, removed)))
+                    .collect();
+                let mut files = Vec::new();
+                let contains = |rel: &str| {
+                    let absolute = repo.root().join(rel);
+                    // Nested clones contribute their own files, never the enclosing repo's entries.
+                    let own = self.at_root(&absolute).or_else(|| self.for_path(&absolute));
+                    own.is_some_and(|r| r.root() == repo.root()) && paths.iter().any(|p| absolute.starts_with(p))
+                };
+                for mut file in ops::parse_name_status(&names.stdout_str()) {
+                    if cancel.is_cancelled() {
+                        return Err(IdeError::cancelled());
+                    }
+                    let new_in = contains(&file.path);
+                    let old_in = file.old_path.as_deref().is_some_and(contains);
+                    if !new_in && !old_in {
+                        continue;
+                    }
+                    let original = file.path.clone();
+                    if file.old_path.is_some() && new_in != old_in {
+                        if old_in {
+                            file.path = file.old_path.take().unwrap();
+                            file.kind = ChangeKind::Deleted;
+                        } else {
+                            file.old_path = None;
+                            file.kind = ChangeKind::Added;
+                        }
+                    }
+                    let count = |path: &str| stats.get(path).copied().unwrap_or_default();
+                    let (added, removed) = match &file.old_path {
+                        Some(old) => (count(&original).0, count(old).1),
+                        None => count(&file.path),
+                    };
+                    files.push(WorkingTreeChange {
+                        path: file.path,
+                        kind: file.kind,
+                        old_path: file.old_path,
+                        added,
+                        removed,
+                    });
+                }
+                if files.iter().any(|f| f.kind == ChangeKind::Renamed) {
+                    let renamed =
+                        run(&["diff", "--numstat", "-z", "-M", "--no-ext-diff", "--no-textconv", &resolved, "--"])?;
+                    let indexes: std::collections::HashMap<_, _> = files
+                        .iter()
+                        .enumerate()
+                        .filter(|(_, f)| f.kind == ChangeKind::Renamed)
+                        .map(|(index, f)| (f.path.clone(), index))
+                        .collect();
+                    let mut records =
+                        renamed.stdout_str().split('\0').map(str::to_owned).collect::<Vec<_>>().into_iter();
+                    while let Some(record) = records.next() {
+                        if cancel.is_cancelled() {
+                            return Err(IdeError::cancelled());
+                        }
+                        let fields: Vec<_> = record.splitn(3, '\t').collect();
+                        if fields.len() == 3 && fields[2].is_empty() {
+                            let _old = records.next();
+                            if let Some(path) = records.next()
+                                && let Some(index) = indexes.get(&path)
+                            {
+                                let file = &mut files[*index];
+                                file.added = fields[0].parse().unwrap_or(0);
+                                file.removed = fields[1].parse().unwrap_or(0);
+                            }
+                        }
+                    }
+                }
+                let untracked = run(&["ls-files", "--others", "--exclude-standard", "-z"])?;
+                for path in untracked.stdout_str().split('\0').filter(|p| !p.is_empty() && contains(p)) {
+                    if cancel.is_cancelled() {
+                        return Err(IdeError::cancelled());
+                    }
+                    let absolute = repo.root().join(path);
+                    // Match the existing diff viewer's large/binary-file policy without loading large files for counts.
+                    let added = if std::fs::metadata(&absolute).is_ok_and(|m| m.len() <= 10 * 1024 * 1024) {
+                        let bytes = std::fs::read(&absolute).unwrap_or_default();
+                        if bytes.contains(&0) {
+                            0
+                        } else {
+                            (bytes.iter().filter(|b| **b == b'\n').count()
+                                + usize::from(!bytes.is_empty() && bytes.last() != Some(&b'\n')))
+                                as u32
+                        }
+                    } else {
+                        0
+                    };
+                    files.push(WorkingTreeChange {
+                        path: path.to_owned(),
+                        kind: ChangeKind::Untracked,
+                        old_path: None,
+                        added,
+                        removed: 0,
+                    });
+                }
+                files.sort_by(|a, b| a.path.cmp(&b.path));
+                Ok((resolved, files))
+            };
+            let comparison = match compare() {
+                Ok((revision, files)) => {
+                    RepositoryComparison { root, revision: Some(revision), files, error: None, missing_revision: false }
+                }
+                Err(_) if cancel.is_cancelled() => return Err(IdeError::cancelled()),
+                Err(e) => RepositoryComparison {
+                    root,
+                    revision: None,
+                    files: Vec::new(),
+                    error: (!missing_revision).then_some(e.message),
+                    missing_revision,
+                },
+            };
+            result.repositories.push(comparison);
+        }
+        Ok(result)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::process::Command;
+
+    fn git(root: &Path, args: &[&str]) {
+        let output = Command::new("git").current_dir(root).args(args).output().unwrap();
+        assert!(output.status.success(), "{args:?}: {}", String::from_utf8_lossy(&output.stderr));
+    }
+
+    fn write(root: &Path, path: &str, text: &str) {
+        let path = root.join(path);
+        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+        std::fs::write(path, text).unwrap();
+    }
+
+    fn init(root: &Path, branch: &str) {
+        std::fs::create_dir_all(root).unwrap();
+        git(root, &["init", "-q", "-b", branch]);
+        git(root, &["config", "user.name", "Test"]);
+        git(root, &["config", "user.email", "[email protected]"]);
+        write(root, "src/文件 name.txt", "old\n");
+        write(root, "src/move.txt", "move\n");
+        write(root, "other/stable.txt", "stable\n");
+        git(root, &["add", "."]);
+        git(root, &["commit", "-qm", "initial"]);
+    }
+
+    #[test]
+    fn subtree_union_worktree_untracked_and_rename_boundaries() {
+        let temp = tempfile::tempdir().unwrap();
+        let root = normalized(temp.path());
+        init(&root, "main");
+        git(&root, &["switch", "-qc", "feature"]);
+        git(&root, &["mv", "src/move.txt", "other/moved.txt"]);
+        git(&root, &["commit", "-qm", "move out"]);
+        write(&root, "src/文件 name.txt", "old\nnew\n");
+        write(&root, "src/untracked space 中文.txt", "new\nfile\n");
+        write(&root, "other/stable.txt", "changed\n");
+        let repos = Repos::discover(&root, &|_| false).unwrap();
+        let cancel = CancellationToken::new();
+        let result = repos.compare_paths(&[root.join("src")], "main", None, &cancel).unwrap();
+        assert_eq!(result.repositories.len(), 1);
+        let files = &result.repositories[0].files;
+        assert_eq!(files.len(), 3, "{files:?}");
+        let moved = files.iter().find(|f| f.path == "src/move.txt").unwrap();
+        assert_eq!(moved.kind, ChangeKind::Deleted);
+        assert_eq!((moved.added, moved.removed), (0, 1));
+        assert!(moved.old_path.is_none());
+        let changed = files.iter().find(|f| f.path == "src/文件 name.txt").unwrap();
+        assert_eq!((changed.added, changed.removed), (1, 0));
+        let untracked = files.iter().find(|f| f.path == "src/untracked space 中文.txt").unwrap();
+        assert_eq!((untracked.kind, untracked.added), (ChangeKind::Untracked, 2));
+        let union = repos
+            .compare_paths(&[root.join("src"), root.join("other"), root.join("src")], "main", None, &cancel)
+            .unwrap();
+        assert_eq!(union.repositories[0].files.len(), 4);
+        let rename = union.repositories[0].files.iter().find(|f| f.path == "other/moved.txt").unwrap();
+        assert_eq!(rename.kind, ChangeKind::Renamed);
+        assert_eq!(rename.old_path.as_deref(), Some("src/move.txt"));
+        assert_eq!((rename.added, rename.removed), (0, 0));
+        let into = repos.compare_paths(&[root.join("other")], "main", None, &cancel).unwrap();
+        assert_eq!(
+            into.repositories[0].files.iter().find(|f| f.path == "other/moved.txt").unwrap().kind,
+            ChangeKind::Added
+        );
+    }
+
+    #[test]
+    fn workspace_roots_missing_revision_loose_paths_and_empty_results() {
+        let temp = tempfile::tempdir().unwrap();
+        let root = normalized(temp.path());
+        for name in ["client", "server", "admin"] {
+            init(&root.join(name), if name == "admin" { "trunk" } else { "main" });
+        }
+        write(&root, "loose/readme.txt", "not git\n");
+        write(&root.join("client"), "src/new.txt", "client\n");
+        write(&root.join("server"), "src/文件 name.txt", "server\n");
+        let repos = Repos::discover(&root, &|_| false).unwrap();
+        let scope = repos.compare_scope(std::slice::from_ref(&root));
+        assert_eq!(scope.repositories.len(), 3);
+        assert_eq!(scope.skipped_paths, [IpcPath(root.join("loose"))]);
+        assert!(!scope.single_file);
+        assert!(repos.compare_scope(&[root.join("client/src/文件 name.txt")]).single_file);
+        let cancel = CancellationToken::new();
+        let result = repos.compare_paths(&[root.clone(), root.join("loose")], "main", None, &cancel).unwrap();
+        assert_eq!(result.repositories.len(), 3);
+        assert_eq!(result.repositories.iter().filter(|r| r.missing_revision).count(), 1);
+        assert!(result.repositories[0].missing_revision, "admin lacks main");
+        assert!(result.repositories[0].error.is_none());
+        assert_eq!(result.repositories[1].files.len(), 1);
+        assert_eq!(result.repositories[2].files.len(), 1);
+        assert_eq!(result.skipped_paths, [IpcPath(root.join("loose"))]);
+        let filtered =
+            repos.compare_paths(std::slice::from_ref(&root), "main", Some(&[root.join("server")]), &cancel).unwrap();
+        assert_eq!(filtered.repositories.len(), 1);
+        assert_eq!(filtered.repositories[0].root.0, root.join("server"));
+        let empty = repos.compare_paths(&[root.join("server/other")], "main", None, &cancel).unwrap();
+        assert!(empty.repositories[0].files.is_empty());
+        let loose = repos.compare_paths(&[root.join("loose")], "main", None, &cancel).unwrap();
+        assert!(loose.repositories.is_empty());
+        assert_eq!(loose.skipped_paths, [IpcPath(root.join("loose"))]);
+        cancel.cancel();
+        assert!(repos.compare_paths(&[root], "main", None, &cancel).is_err());
+    }
+
+    #[test]
+    fn nested_repositories_are_not_reported_twice_and_binary_counts_are_zero() {
+        let temp = tempfile::tempdir().unwrap();
+        let root = normalized(temp.path());
+        init(&root, "main");
+        init(&root.join("nested"), "main");
+        write(&root.join("nested"), "src/new.txt", "nested\n");
+        std::fs::write(root.join("src/image.bin"), [0, 1, 2]).unwrap();
+        let repos = Repos::discover(&root, &|_| false).unwrap();
+        let result = repos.compare_paths(std::slice::from_ref(&root), "main", None, &CancellationToken::new()).unwrap();
+        assert_eq!(result.repositories.len(), 2);
+        assert_eq!(result.repositories[0].files.len(), 1);
+        assert_eq!(result.repositories[0].files[0].added, 0);
+        assert_eq!(result.repositories[1].files.len(), 1);
+        let nested = repos.compare_paths(&[root.join("nested")], "main", None, &CancellationToken::new()).unwrap();
+        assert_eq!(nested.repositories.len(), 1);
+        assert_eq!(nested.repositories.iter().map(|r| r.files.len()).sum::<usize>(), 1);
+    }
+    #[test]
+    fn skipped_children_only_report_content_outside_repositories() {
+        let temp = tempfile::tempdir().unwrap();
+        let root = normalized(temp.path());
+        init(&root.join("services/server"), "main");
+        init(&root.join("client"), "main");
+        write(&root, ".openidea/state.json", "{}");
+        write(&root, ".git/config", "ignored metadata");
+        let repos = Repos::discover(&root, &|_| false).unwrap();
+        assert!(repos.compare_scope(std::slice::from_ref(&root)).skipped_paths.is_empty());
+        write(&root, "services/notes.txt", "loose nested content");
+        write(&root, "loose/readme.txt", "loose");
+        write(&root, "readme.txt", "loose file");
+        let scope = repos.compare_scope(&[root.clone(), root.join("loose")]);
+        assert_eq!(
+            scope.skipped_paths,
+            [IpcPath(root.join("loose")), IpcPath(root.join("readme.txt")), IpcPath(root.join("services")),]
+        );
+        assert!(scope.skipped_paths[0].0.to_string_lossy().ends_with(std::path::MAIN_SEPARATOR));
+    }
+
+    #[test]
+    fn missing_revision_is_typed_and_other_errors_keep_only_the_message() {
+        let temp = tempfile::tempdir().unwrap();
+        let root = normalized(temp.path());
+        init(&root, "main");
+        let repos = Repos::discover(&root, &|_| false).unwrap();
+        let cancel = CancellationToken::new();
+        let result = repos.compare_paths(std::slice::from_ref(&root), "missing-revision", None, &cancel).unwrap();
+        assert!(result.repositories[0].missing_revision);
+        assert!(result.repositories[0].error.is_none());
+        std::fs::write(root.join(".git/config"), "[broken").unwrap();
+        let result = repos.compare_paths(&[root], "main", None, &cancel).unwrap();
+        assert!(!result.repositories[0].missing_revision);
+        let error = result.repositories[0].error.as_deref().unwrap();
+        assert!(error.contains("bad config"), "{error}");
+        assert!(!error.starts_with("Internal:"), "{error}");
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn untracked_read_and_metadata_failures_leave_files_with_zero_counts() {
+        use std::os::unix::fs::symlink;
+        let temp = tempfile::tempdir().unwrap();
+        let root = normalized(temp.path());
+        init(&root, "main");
+        // Reading a directory fails after successful metadata; a dangling link fails metadata.
+        symlink(root.join("src"), root.join("unreadable")).unwrap();
+        symlink(root.join("vanished"), root.join("missing")).unwrap();
+        write(&root, "new.txt", "still counted\n");
+        let repos = Repos::discover(&root, &|_| false).unwrap();
+        let result = repos.compare_paths(&[root], "main", None, &CancellationToken::new()).unwrap();
+        let repo = &result.repositories[0];
+        assert!(repo.error.is_none(), "{repo:?}");
+        assert_eq!(repo.files.len(), 3);
+        for name in ["unreadable", "missing"] {
+            let file = repo.files.iter().find(|f| f.path == name).unwrap();
+            assert_eq!((file.kind, file.added, file.removed), (ChangeKind::Untracked, 0, 0));
+        }
+        assert_eq!(repo.files.iter().find(|f| f.path == "new.txt").unwrap().added, 1);
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn restricted_comparison_does_not_execute_repository_commands() {
+        use std::os::unix::fs::PermissionsExt;
+        let temp = tempfile::tempdir().unwrap();
+        let root = normalized(temp.path());
+        init(&root, "main");
+        let script = root.join(".git/marker.sh");
+        let marker = root.join(".git/executed");
+        std::fs::write(&script, "#!/bin/sh\ntouch .git/executed\n").unwrap();
+        std::fs::set_permissions(&script, std::fs::Permissions::from_mode(0o755)).unwrap();
+        let script = script.to_str().unwrap();
+        for key in [
+            "core.fsmonitor",
+            "filter.marker.clean",
+            "filter.marker.process",
+            "diff.marker.command",
+            "diff.marker.textconv",
+        ] {
+            git(&root, &["config", key, script]);
+        }
+        git(&root, &["config", "filter.marker.required", "true"]);
+        write(&root, ".gitattributes", "*.txt filter=marker diff=marker\n");
+        write(&root, "src/文件 name.txt", "changed\n");
+        write(&root, "new.txt", "untracked\n");
+        let repos = Repos::discover(&root, &|_| false).unwrap();
+        for repo in repos.all() {
+            repo.set_execution_allowed(false);
+        }
+        let result = repos.compare_paths(std::slice::from_ref(&root), "main", None, &CancellationToken::new()).unwrap();
+        assert!(result.repositories[0].error.is_none(), "{result:?}");
+        assert_eq!(result.repositories[0].files.len(), 3);
+        assert!(!marker.exists(), "Restricted Mode executed a repository command");
+        // Prove the fixture's fsmonitor hook is active when the shared wrapper is bypassed.
+        git(&root, &["ls-files"]);
+        assert!(marker.exists(), "control invocation did not run fsmonitor");
+    }
+}
@@ -453,6 +453,7 @@ pub struct ChangelistState {
 mod blame;
 pub mod changelists;
 mod cli;
+mod compare;
 mod diff;
 mod history;
 mod ignore;
@@ -464,6 +465,7 @@ mod refs;
 mod remotes;
 mod repo;
 mod roots;
+pub use compare::{CompareResult, CompareScope, RepositoryComparison, WorkingTreeChange};
 pub mod shelf;
 mod status;
 pub use index_writes::is_own_index_write;
@@ -3,7 +3,7 @@ use encoding_rs::{Encoding, UTF_8, UTF_16BE, UTF_16LE};
 use ide_core::{IdeError, IdeResult};
 use std::borrow::Cow;

-/// File charset plus an optional reversible ASCII representation (for properties).
+/// File charset plus an optional ASCII representation (for properties).
 /// The host supplies conversion functions so Git and documents share one codec.
 #[derive(Clone, Copy)]
 pub struct TextEncoding {
@@ -1555,6 +1555,14 @@ fn restricted_reads_ignore_executable_repository_configuration() {
    assert!(!repo.log(&LogQuery::default()).unwrap().is_empty());
    repo.merge_versions(&f.path("a.txt"), encoding_rs::UTF_8).unwrap();
    assert!(!f.path("execution.marker").exists());
+    let repos = ide_vcs::Repos::discover(&f.dir, &|_| false).unwrap();
+    for r in repos.all() {
+        r.set_execution_allowed(false);
+    }
+    let compared =
+        repos.compare_paths(std::slice::from_ref(&f.dir), "HEAD", None, &ide_core::CancellationToken::new()).unwrap();
+    assert!(compared.repositories.iter().all(|r| r.error.is_none()));
+    assert!(!f.path("execution.marker").exists());
    // Positive control: the same filter really executes without restriction.
    f.git(&["-c", "core.fsmonitor=false", "diff", "--no-ext-diff", "--no-textconv"]);
    assert!(f.path("execution.marker").exists());
@@ -0,0 +1,505 @@
+//! Disk comparisons use the same excludes and layered ignore files as the project tree.
+use crate::{EntryKind, ExcludeMatcher, rules::GitignoreStack};
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::collections::BTreeMap;
+use std::fs;
+use std::io::Read;
+use std::path::{Path, PathBuf};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum DirectoryCompareStatus {
+    LeftOnly,
+    RightOnly,
+    Different,
+    Equal,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct DirectoryCompareEntry {
+    pub path: String,
+    pub status: DirectoryCompareStatus,
+    pub left_kind: Option<EntryKind>,
+    pub right_kind: Option<EntryKind>,
+    #[specta(optional)]
+    pub left_link: Option<String>,
+    #[specta(optional)]
+    pub right_link: Option<String>,
+}
+
+#[derive(Clone, Debug, Default, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct DirectoryCompareProgress {
+    pub scanned: u32,
+    pub compared: u32,
+    pub total: Option<u32>,
+    pub bytes_read: f64,
+    pub path: String,
+}
+
+struct Entry {
+    kind: EntryKind,
+    size: u64,
+    link: Option<PathBuf>,
+}
+
+fn check(cancel: &CancellationToken) -> IdeResult<()> {
+    if cancel.is_cancelled() { Err(IdeError::cancelled()) } else { Ok(()) }
+}
+
+struct Rules {
+    base: PathBuf,
+    excludes: ExcludeMatcher,
+    ignore: GitignoreStack,
+}
+
+impl Rules {
+    fn new(root: &Path, project: Option<&Path>, excludes: &[String]) -> Self {
+        Self {
+            base: project.filter(|p| root.starts_with(p)).unwrap_or(root).to_path_buf(),
+            excludes: ExcludeMatcher::new(excludes),
+            ignore: GitignoreStack::new(root),
+        }
+    }
+
+    fn excluded(&self, path: &Path, dir: bool) -> bool {
+        path.file_name().is_some_and(|n| n == ".git")
+            || self.excludes.is_excluded(path.strip_prefix(&self.base).unwrap_or(path))
+            || self.ignore.is_ignored(path, dir)
+    }
+}
+
+fn scan(
+    root: &Path,
+    rules: &Rules,
+    cancel: &CancellationToken,
+    progress: &mut DirectoryCompareProgress,
+    emit: &impl Fn(DirectoryCompareProgress),
+) -> IdeResult<BTreeMap<String, Entry>> {
+    if !fs::metadata(root)?.is_dir() {
+        return Err(IdeError::invalid(format!("{} is not a directory", root.display())));
+    }
+    let mut result = BTreeMap::new();
+    let mut pending = vec![root.to_path_buf()];
+    while let Some(dir) = pending.pop() {
+        check(cancel)?;
+        for item in fs::read_dir(dir)? {
+            check(cancel)?;
+            let path = item?.path();
+            let meta = fs::symlink_metadata(&path)?;
+            if rules.excluded(&path, meta.is_dir()) {
+                continue;
+            }
+            let kind = if meta.file_type().is_symlink() {
+                EntryKind::Symlink
+            } else if meta.is_dir() {
+                pending.push(path.clone());
+                EntryKind::Dir
+            } else if meta.is_file() {
+                EntryKind::File
+            } else {
+                continue;
+            };
+            let rel = path.strip_prefix(root).map_err(|e| IdeError::internal(e.to_string()))?;
+            let rel = ide_core::ipc_path::to_ipc(rel);
+            let link = if kind == EntryKind::Symlink { Some(fs::read_link(&path)?) } else { None };
+            result.insert(rel.clone(), Entry { kind, size: meta.len(), link });
+            progress.scanned += 1;
+            progress.path = rel;
+            emit(progress.clone());
+        }
+    }
+    Ok(result)
+}
+
+fn hash(
+    path: &Path,
+    cancel: &CancellationToken,
+    progress: &mut DirectoryCompareProgress,
+    emit: &impl Fn(DirectoryCompareProgress),
+) -> IdeResult<gix::hash::ObjectId> {
+    let mut file = fs::File::open(path)?;
+    let mut hash = gix::hash::hasher(gix::hash::Kind::Sha256);
+    let mut buffer = [0; 64 * 1024];
+    loop {
+        check(cancel)?;
+        let len = file.read(&mut buffer)?;
+        if len == 0 {
+            break;
+        }
+        hash.update(&buffer[..len]);
+        progress.bytes_read += len as f64;
+        emit(progress.clone());
+    }
+    hash.try_finalize().map_err(|e| IdeError::internal(e.to_string()))
+}
+
+/// Size checks avoid reading unequal files. Equal-sized files are hashed in bounded,
+/// cancellable chunks; symlinks compare their link text and are never traversed.
+pub fn compare_directories(
+    left: &Path,
+    right: &Path,
+    project: Option<&Path>,
+    excludes: &[String],
+    cancel: &CancellationToken,
+    emit: impl Fn(DirectoryCompareProgress),
+) -> IdeResult<Vec<DirectoryCompareEntry>> {
+    check(cancel)?;
+    let mut progress = DirectoryCompareProgress::default();
+    emit(progress.clone());
+    let l = scan(left, &Rules::new(left, project, excludes), cancel, &mut progress, &emit)?;
+    let r = scan(right, &Rules::new(right, project, excludes), cancel, &mut progress, &emit)?;
+    let mut paths: Vec<_> = l.keys().chain(r.keys()).cloned().collect();
+    paths.sort();
+    paths.dedup();
+    progress.total = Some(paths.len() as u32);
+    let mut rows = BTreeMap::new();
+    for path in paths {
+        check(cancel)?;
+        progress.path.clone_from(&path);
+        let status = match (l.get(&path), r.get(&path)) {
+            (Some(_), None) => DirectoryCompareStatus::LeftOnly,
+            (None, Some(_)) => DirectoryCompareStatus::RightOnly,
+            (Some(a), Some(b)) => {
+                let equal = a.kind == b.kind
+                    && match a.kind {
+                        EntryKind::Dir => true,
+                        EntryKind::Symlink => a.link == b.link,
+                        EntryKind::File => {
+                            a.size == b.size
+                                && hash(&left.join(&path), cancel, &mut progress, &emit)?
+                                    == hash(&right.join(&path), cancel, &mut progress, &emit)?
+                        }
+                    };
+                if equal { DirectoryCompareStatus::Equal } else { DirectoryCompareStatus::Different }
+            }
+            _ => unreachable!(),
+        };
+        rows.insert(
+            path.clone(),
+            DirectoryCompareEntry {
+                path: path.clone(),
+                status,
+                left_kind: l.get(&path).map(|e| e.kind),
+                right_kind: r.get(&path).map(|e| e.kind),
+                left_link: l.get(&path).and_then(|e| e.link.as_ref()).map(|p| p.to_string_lossy().into_owned()),
+                right_link: r.get(&path).and_then(|e| e.link.as_ref()).map(|p| p.to_string_lossy().into_owned()),
+            },
+        );
+        progress.compared += 1;
+        emit(progress.clone());
+    }
+    let changed: Vec<_> =
+        rows.values().filter(|r| r.status != DirectoryCompareStatus::Equal).map(|r| r.path.clone()).collect();
+    for path in changed {
+        for parent in Path::new(&path).ancestors().skip(1) {
+            if let Some(row) = rows.get_mut(&ide_core::ipc_path::to_ipc(parent))
+                && row.status == DirectoryCompareStatus::Equal
+            {
+                row.status = DirectoryCompareStatus::Different;
+            }
+        }
+    }
+    check(cancel)?;
+    Ok(rows.into_values().collect())
+}
+
+/// Merges a subtree without following links inside the comparison roots. Existing files
+/// require explicit overwrite; directory merges preserve destination-only entries.
+pub fn copy_merge(
+    from: &Path,
+    to: &Path,
+    overwrite: bool,
+    project: Option<&Path>,
+    excludes: &[String],
+    roots: (&Path, &Path),
+) -> IdeResult<()> {
+    fn resolve(path: &Path) -> IdeResult<PathBuf> {
+        if path.exists() {
+            return Ok(dunce::canonicalize(path)?);
+        }
+        let parent = path.parent().ok_or_else(|| IdeError::invalid("copy requires an absolute path"))?;
+        Ok(resolve(parent)?.join(path.file_name().ok_or_else(|| IdeError::invalid("missing file name"))?))
+    }
+    if !from.is_absolute() || !to.is_absolute() {
+        return Err(IdeError::invalid("copy requires absolute paths"));
+    }
+    if !from.starts_with(roots.0) || !to.starts_with(roots.1) {
+        return Err(IdeError::invalid("copy paths must belong to the comparison roots"));
+    }
+    let source = resolve(from)?;
+    let target = resolve(to)?;
+    if source.starts_with(&target) || target.starts_with(&source) {
+        return Err(IdeError::invalid("cannot copy overlapping paths"));
+    }
+    for parent in to.ancestors().skip(1) {
+        // The user explicitly selected this root; aliases above it (e.g. /tmp
+        // on macOS) are valid. Links inside the copied subtree are not followed.
+        if to == roots.1 || parent == roots.1 {
+            break;
+        }
+        if fs::symlink_metadata(parent).is_ok_and(|m| m.file_type().is_symlink()) {
+            return Err(IdeError::invalid("cannot copy through a destination symlink"));
+        }
+    }
+    let source_base = project.filter(|p| from.starts_with(p)).or(Some(roots.0));
+    let target_base = project.filter(|p| to.starts_with(p)).or(Some(roots.1));
+    let rules = Rules::new(from, source_base, excludes);
+    let target_rules = Rules::new(to, target_base, excludes);
+    let mut pending = vec![(from.to_path_buf(), to.to_path_buf())];
+    while let Some((src, dst)) = pending.pop() {
+        let meta = fs::symlink_metadata(&src)?;
+        if rules.excluded(&src, meta.is_dir()) || target_rules.excluded(&dst, meta.is_dir()) {
+            continue;
+        }
+        let existing = fs::symlink_metadata(&dst).ok();
+        let merge = meta.is_dir() && existing.as_ref().is_some_and(|m| m.is_dir());
+        if existing.is_some() && !merge && !overwrite {
+            return Err(std::io::Error::new(std::io::ErrorKind::AlreadyExists, dst.display().to_string()).into());
+        }
+        if meta.is_dir() {
+            if existing.is_some() && !merge {
+                crate::delete(&dst)?;
+            }
+            fs::create_dir_all(&dst)?;
+            for entry in fs::read_dir(&src)? {
+                let entry = entry?;
+                pending.push((entry.path(), dst.join(entry.file_name())));
+            }
+        } else {
+            if let Some(parent) = dst.parent() {
+                fs::create_dir_all(parent)?;
+            }
+            // Stage the complete file before touching its destination.
+            static NEXT: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(0);
+            let id = NEXT.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+            let temp = dst.with_file_name(format!(".openidea-copy-{}-{id}", std::process::id()));
+            let mut staged = false;
+            let result: IdeResult<()> = (|| {
+                #[cfg(windows)]
+                if meta.file_type().is_symlink() {
+                    use std::os::windows::fs::{FileTypeExt, symlink_dir, symlink_file};
+                    let target = fs::read_link(&src)?;
+                    if meta.file_type().is_symlink_dir() {
+                        symlink_dir(target, &temp)?;
+                    } else {
+                        symlink_file(target, &temp)?;
+                    }
+                } else {
+                    crate::copy(&src, &temp)?;
+                }
+                #[cfg(not(windows))]
+                crate::copy(&src, &temp)?;
+                staged = true;
+                // Recheck after staging: another writer may have created the target.
+                if fs::symlink_metadata(&dst).is_ok() {
+                    if !overwrite {
+                        return Err(
+                            std::io::Error::new(std::io::ErrorKind::AlreadyExists, dst.display().to_string()).into()
+                        );
+                    }
+                    crate::delete(&dst)?;
+                }
+                fs::rename(&temp, &dst)?;
+                Ok(())
+            })();
+            if let Err(error) = &result
+                && (staged || error.kind != ide_core::error::ErrorKind::AlreadyExists)
+            {
+                let _ = crate::delete_permanently(&temp);
+            }
+            result?;
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ide_core::error::ErrorKind;
+
+    fn put(root: &Path, path: &str, content: &[u8]) {
+        let path = root.join(path);
+        fs::create_dir_all(path.parent().unwrap()).unwrap();
+        fs::write(path, content).unwrap();
+    }
+
+    #[test]
+    fn reports_add_delete_modify_equal_binary_unicode_empty_and_type_conflicts() {
+        let tmp = tempfile::tempdir().unwrap();
+        let left = tmp.path().join("left");
+        let right = tmp.path().join("right");
+        put(&left, "子目录/仅左.txt", b"left");
+        put(&right, "only-right", b"right");
+        for (path, a, b) in [
+            ("same", b"same".as_slice(), b"same".as_slice()),
+            ("binary", &[0, 255, 10], &[0, 254, 10]),
+            ("size", b"a", b"bb"),
+            ("conflict", b"file", b""),
+        ] {
+            put(&left, path, a);
+            if path == "conflict" {
+                put(&right, "conflict/child", b"child");
+            } else {
+                put(&right, path, b);
+            }
+        }
+        fs::create_dir(left.join("empty")).unwrap();
+        fs::create_dir(right.join("empty")).unwrap();
+        let rows = compare_directories(&left, &right, None, &[], &CancellationToken::new(), |_| {}).unwrap();
+        let status = |path| rows.iter().find(|r| r.path == path).unwrap().status;
+        assert_eq!(status("same"), DirectoryCompareStatus::Equal);
+        assert_eq!(status("empty"), DirectoryCompareStatus::Equal);
+        for path in ["binary", "size", "conflict"] {
+            assert_eq!(status(path), DirectoryCompareStatus::Different);
+        }
+        assert_eq!(status("子目录/仅左.txt"), DirectoryCompareStatus::LeftOnly);
+        assert_eq!(status("only-right"), DirectoryCompareStatus::RightOnly);
+        assert_eq!(status("conflict/child"), DirectoryCompareStatus::RightOnly);
+    }
+
+    #[test]
+    fn applies_project_anchored_excludes_and_layered_ignores() {
+        let tmp = tempfile::tempdir().unwrap();
+        let left = tmp.path().join("left");
+        let right = tmp.path().join("right");
+        for root in [&left, &right] {
+            put(root, "nested/node_modules/x", b"ignored");
+            put(root, "target/x", b"ignored");
+            put(root, ".git/config", b"ignored");
+            put(root, "generated/x", b"ignored");
+            put(root, ".gitignore", b"*.log\n");
+            put(root, "nested/debug.log", b"ignored");
+            put(root, "kept", b"kept");
+        }
+        let excludes = ["**/node_modules", "**/target", "/left/generated", "/right/generated"].map(String::from);
+        let rows =
+            compare_directories(&left, &right, Some(tmp.path()), &excludes, &CancellationToken::new(), |_| {}).unwrap();
+        assert!(
+            rows.iter()
+                .all(|r| !["node_modules", "target", ".git/", "generated", ".log"].iter().any(|p| r.path.contains(p)))
+        );
+        assert!(rows.iter().any(|r| r.path == "kept"));
+    }
+
+    #[test]
+    fn cancellation_stops_before_scan_during_scan_and_during_hashing() {
+        let tmp = tempfile::tempdir().unwrap();
+        let left = tmp.path().join("left");
+        let right = tmp.path().join("right");
+        put(&left, "big", &vec![1; 1024 * 1024]);
+        put(&right, "big", &vec![1; 1024 * 1024]);
+        for phase in 0..3 {
+            let cancel = CancellationToken::new();
+            if phase == 0 {
+                cancel.cancel();
+            }
+            let result = compare_directories(&left, &right, None, &[], &cancel, |p| {
+                if phase == 1 && p.scanned > 0 || phase == 2 && p.bytes_read > 0.0 {
+                    cancel.cancel();
+                }
+            });
+            assert_eq!(result.unwrap_err().kind, ErrorKind::Cancelled);
+        }
+    }
+
+    #[test]
+    fn size_mismatches_are_not_hashed_and_directory_status_tracks_children() {
+        let tmp = tempfile::tempdir().unwrap();
+        let left = tmp.path().join("left");
+        let right = tmp.path().join("right");
+        put(&left, "nested/file", b"a");
+        put(&right, "nested/file", b"ab");
+        let bytes = std::cell::Cell::new(0.0);
+        let rows =
+            compare_directories(&left, &right, None, &[], &CancellationToken::new(), |p| bytes.set(p.bytes_read))
+                .unwrap();
+        assert_eq!(bytes.get(), 0.0);
+        assert!(rows.iter().all(|r| r.status == DirectoryCompareStatus::Different));
+    }
+
+    #[test]
+    fn merges_copies_with_explicit_overwrite_and_keeps_destination_only_files() {
+        let tmp = tempfile::tempdir().unwrap();
+        let left = tmp.path().join("left");
+        let right = tmp.path().join("right");
+        put(&left, "file", b"new");
+        put(&left, "target/ignored", b"ignored");
+        put(&right, "file", b"old");
+        put(&right, "keep", b"keep");
+        assert_eq!(
+            copy_merge(&left, &right, false, None, &["target".into()], (&left, &right)).unwrap_err().kind,
+            ErrorKind::AlreadyExists
+        );
+        assert_eq!(fs::read(right.join("file")).unwrap(), b"old");
+        copy_merge(&left, &right, true, None, &["target".into()], (&left, &right)).unwrap();
+        assert_eq!(fs::read(right.join("file")).unwrap(), b"new");
+        assert_eq!(fs::read(right.join("keep")).unwrap(), b"keep");
+        assert!(!right.join("target").exists());
+        for (from, to) in [(&left, left.clone()), (&left, left.join("child")), (&right, tmp.path().to_path_buf())] {
+            assert_eq!(
+                copy_merge(from, &to, true, None, &[], (tmp.path(), tmp.path())).unwrap_err().kind,
+                ErrorKind::InvalidInput
+            );
+        }
+    }
+
+    #[test]
+    fn subtree_copy_keeps_excludes_anchored_to_each_comparison_root() {
+        let tmp = tempfile::tempdir().unwrap();
+        let left = tmp.path().join("left");
+        let right = tmp.path().join("right");
+        put(&left, "sub/build/keep", b"included below sub");
+        put(&left, "sub/protected", b"do not overwrite");
+        put(&right, "sub/protected", b"keep destination");
+        put(&right, ".gitignore", b"sub/protected\n");
+        copy_merge(&left.join("sub"), &right.join("sub"), true, None, &["/build".into()], (&left, &right)).unwrap();
+        assert_eq!(fs::read(right.join("sub/build/keep")).unwrap(), b"included below sub");
+        assert_eq!(fs::read(right.join("sub/protected")).unwrap(), b"keep destination");
+    }
+
+    #[test]
+    fn confirmed_copy_replaces_file_directory_type_conflicts() {
+        let tmp = tempfile::tempdir().unwrap();
+        let left = tmp.path().join("left");
+        let right = tmp.path().join("right");
+        put(&left, "file", b"file");
+        put(&right, "file/child", b"old directory");
+        put(&left, "tree/child", b"new directory");
+        put(&right, "tree", b"old file");
+        for path in ["file", "tree"] {
+            copy_merge(&left.join(path), &right.join(path), true, None, &[], (&left, &right)).unwrap();
+        }
+        assert_eq!(fs::read(right.join("file")).unwrap(), b"file");
+        assert_eq!(fs::read(right.join("tree/child")).unwrap(), b"new directory");
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn symlinks_compare_link_text_and_are_not_followed_when_copying() {
+        use std::os::unix::fs::symlink;
+        let tmp = tempfile::tempdir().unwrap();
+        let left = tmp.path().join("left");
+        let right = tmp.path().join("right");
+        fs::create_dir(&left).unwrap();
+        fs::create_dir(&right).unwrap();
+        symlink(".", left.join("loop")).unwrap();
+        symlink("missing", right.join("loop")).unwrap();
+        let rows = compare_directories(&left, &right, None, &[], &CancellationToken::new(), |_| {}).unwrap();
+        assert_eq!(rows.len(), 1);
+        assert_eq!(rows[0].status, DirectoryCompareStatus::Different);
+        copy_merge(&left.join("loop"), &right.join("copied"), false, None, &[], (&left, &right)).unwrap();
+        assert_eq!(fs::read_link(right.join("copied")).unwrap(), PathBuf::from("."));
+        symlink(&right, tmp.path().join("alias")).unwrap();
+        assert_eq!(
+            copy_merge(&left.join("loop"), &tmp.path().join("alias/new"), true, None, &[], (tmp.path(), tmp.path()))
+                .unwrap_err()
+                .kind,
+            ErrorKind::InvalidInput
+        );
+    }
+}
@@ -62,20 +62,19 @@ pub fn decode_properties_escapes(text: &str) -> String {
 }

 /// Serializes displayed properties text as ASCII, using uppercase UTF-16 units.
+/// Existing ASCII Unicode escapes retain their spelling and meaning on disk.
 pub fn encode_properties_ascii(text: &str) -> String {
    use std::fmt::Write;
    let mut out = String::with_capacity(text.len());
    let mut rest = text;
    while let Some(c) = rest.chars().next() {
-        let current = rest;
        rest = &rest[c.len_utf8()..];
        if c == '\\' {
            if rest.starts_with('\\') {
                out.push_str("\\\\");
                rest = &rest[1..];
-            } else if unicode_character(current).is_some() || rest.chars().next().is_some_and(|next| !next.is_ascii()) {
-                // Keep a literal backslash from swallowing a generated escape,
-                // or becoming a Unicode escape on the next load.
+            } else if rest.chars().next().is_some_and(|next| !next.is_ascii()) {
+                // Keep a literal backslash from swallowing a generated escape.
                out.push_str("\\u005C");
            } else {
                out.push(c);
@@ -387,13 +386,32 @@ mod tests {
        for text in ["plain=ASCII\r\n", r"escaped=\\u0041", r"bad=\u12xz", r"bad=\uD800"] {
            assert_eq!(encode_properties_ascii(text), text);
        }
-        for text in ["你好😀", "\0", "\\中", "\\\\中", "\\\\\\😀", r"\u0041", r"\\u0041", r"\uD83D\uDE00"] {
+        for text in ["你好😀", "\0", "\\中", "\\\\中", "\\\\\\😀", r"\\u0041"] {
            let ascii = encode_properties_ascii(text);
            assert!(ascii.is_ascii());
            assert_eq!(decode_properties_escapes(&ascii), text, "{ascii}");
        }
    }

+    #[test]
+    fn properties_ascii_escapes_are_not_escaped_again() {
+        for text in [
+            r"test.key2=\u4F60\u597D",
+            r"test.key3=\u4f60\u597d",
+            r"ascii=\u0041\u005C\u000A",
+            r"emoji=\uD83D\uDE00",
+            r"slashes=\\u4F60 \\\u4F60 \\\\u4F60",
+            r"bad=\u123 \u12xz \uu0041 \uD800 \uDC00",
+        ] {
+            assert_eq!(encode_properties_ascii(text), text, "{text}");
+        }
+        let mixed = "raw=\\u4f60\\u597d; native=你好😀";
+        let expected = r"raw=\u4f60\u597d; native=\u4F60\u597D\uD83D\uDE00";
+        assert_eq!(encode_properties_ascii(mixed), expected);
+        assert_eq!(encode_properties_ascii(expected), expected);
+        assert_eq!(decode_properties_escapes(expected), "raw=你好; native=你好😀");
+    }
+
    #[test]
    fn properties_line_terminator_escapes_survive_an_edit() {
        let source = r"key=one\u000Atwo\u000Dthree";
@@ -2,6 +2,7 @@

 mod archive;
 mod bytes;
+mod compare;
 mod encoding;
 mod ops;
 mod rules;
@@ -20,6 +21,9 @@ pub use archive::{
    read_archive_entry, split_archive_path,
 };
 pub use bytes::{ByteRange, FileProbe, MAX_RANGE_LEN, base64, image_mime, probe, read_data_url, read_range};
+pub use compare::{
+    DirectoryCompareEntry, DirectoryCompareProgress, DirectoryCompareStatus, compare_directories, copy_merge,
+};
 use encoding::SNIFF_LEN;
 pub use encoding::{
    LARGE_FILE_THRESHOLD, MAX_OPEN_SIZE, READ_ONLY_THRESHOLD, decode_properties_escapes, encode,
@@ -0,0 +1,111 @@
+use super::{ProjectRoots, RootKind};
+use ide_core::settings::ProjectStructureSettings;
+use std::path::{Component, Path};
+
+/// Source paths for jdtls's unmanaged project, relative to its workspace folder.
+/// Maven, Gradle and Eclipse own their source model; other layouts retain jdtls inference.
+pub fn unmanaged_java_source_paths(
+    project: &Path,
+    server_root: &Path,
+    settings: &ProjectStructureSettings,
+) -> Option<Vec<String>> {
+    if ["pom.xml", "build.gradle", "build.gradle.kts", "settings.gradle", "settings.gradle.kts", ".project"]
+        .iter()
+        .any(|name| server_root.join(name).is_file())
+    {
+        return None;
+    }
+    let roots = ProjectRoots::compute(Vec::new(), settings);
+    let mut paths: Vec<String> = roots
+        .roots
+        .iter()
+        .filter(|r| matches!(r.kind, RootKind::Source | RootKind::Test))
+        .filter(|r| Path::new(&r.path).components().all(|c| matches!(c, Component::Normal(_))))
+        .filter_map(|r| {
+            let absolute = project.join(&r.path);
+            let relative = absolute.strip_prefix(server_root).ok()?;
+            let path = relative.to_string_lossy().replace('\\', "/");
+            Some(if path.is_empty() { ".".into() } else { path })
+        })
+        .collect();
+    if paths.is_empty() {
+        // jdtls can infer the package directory itself as a source root. Give
+        // conventional layouts an unambiguous base without guessing other layouts.
+        paths = ["src/main/java", "src/test/java"]
+            .into_iter()
+            .filter(|p| server_root.join(p).is_dir())
+            .map(str::to_owned)
+            .collect();
+        if paths.is_empty() && server_root.join("src").is_dir() {
+            paths.push("src".into());
+        }
+    }
+    (!paths.is_empty()).then_some(paths)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn marked_sources_and_tests_are_relative_to_the_server() {
+        let dir = tempfile::tempdir().unwrap();
+        let settings = ProjectStructureSettings {
+            source_roots: vec!["./app/generated/".into(), "other/src".into(), "../outside".into()],
+            test_roots: vec!["app/tests".into()],
+            resource_roots: vec!["app/resources".into()],
+            excluded: vec!["app/out".into()],
+            ..Default::default()
+        };
+        assert_eq!(
+            unmanaged_java_source_paths(dir.path(), &dir.path().join("app"), &settings),
+            Some(vec!["generated".into(), "tests".into()])
+        );
+        let settings = ProjectStructureSettings { source_roots: vec![".".into()], ..Default::default() };
+        assert_eq!(unmanaged_java_source_paths(dir.path(), dir.path(), &settings), Some(vec![".".into()]));
+    }
+
+    #[test]
+    fn conventional_layouts_and_other_unmarked_projects() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let settings = ProjectStructureSettings::default();
+        assert_eq!(unmanaged_java_source_paths(root, root, &settings), None);
+        std::fs::create_dir_all(root.join("src")).unwrap();
+        assert_eq!(unmanaged_java_source_paths(root, root, &settings), Some(vec!["src".into()]));
+        std::fs::create_dir_all(root.join("src/main/java")).unwrap();
+        std::fs::create_dir_all(root.join("src/test/java")).unwrap();
+        assert_eq!(
+            unmanaged_java_source_paths(root, root, &settings),
+            Some(vec!["src/main/java".into(), "src/test/java".into()])
+        );
+        let settings = ProjectStructureSettings { source_roots: vec!["custom".into()], ..settings };
+        assert_eq!(unmanaged_java_source_paths(root, root, &settings), Some(vec!["custom".into()]));
+    }
+
+    #[test]
+    fn ant_projects_use_unmanaged_source_roots() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        std::fs::write(root.join("build.xml"), "<project/>\n").unwrap();
+        std::fs::create_dir_all(root.join("src/com/acme")).unwrap();
+        let settings = ProjectStructureSettings::default();
+        assert_eq!(unmanaged_java_source_paths(root, root, &settings), Some(vec!["src".into()]));
+        let settings = ProjectStructureSettings { source_roots: vec!["src".into(), "generated".into()], ..settings };
+        assert_eq!(unmanaged_java_source_paths(root, root, &settings), Some(vec!["generated".into(), "src".into()]));
+    }
+
+    #[test]
+    fn managed_projects_keep_their_build_model() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let settings = ProjectStructureSettings { source_roots: vec!["custom".into()], ..Default::default() };
+        for marker in
+            ["pom.xml", "build.gradle", "build.gradle.kts", "settings.gradle", "settings.gradle.kts", ".project"]
+        {
+            std::fs::write(root.join(marker), "").unwrap();
+            assert_eq!(unmanaged_java_source_paths(root, root, &settings), None, "{marker}");
+            std::fs::remove_file(root.join(marker)).unwrap();
+        }
+    }
+}
@@ -7,9 +7,11 @@

 mod detect;
 mod gradle;
+mod java;
 mod maven;

 pub use detect::{affects_roots, detect};
+pub use java::unmanaged_java_source_paths;

 use ide_core::settings::ProjectStructureSettings;
 use serde::{Deserialize, Serialize};
@@ -641,6 +641,57 @@ fn properties_conversion_uses_displayed_utf16_and_survives_reload() {
    assert!(!f.docs.is_dirty(doc.id).unwrap());
 }

+#[test]
+fn properties_pasted_escapes_survive_save_and_decode_on_reload() {
+    let pasted = "test.key1=Hello\ntest.key2=\\u4F60\\u597D\ntest.key3=\\u4f60\\u597d\n";
+    let displayed = "test.key1=Hello\ntest.key2=你好\ntest.key3=你好\n";
+    for encoding in ["utf-8", "iso-8859-1", "utf-16le"] {
+        for eol in ["\n", "\r\n"] {
+            let f = fixture();
+            let path = f.root.join("test_zh_CN.properties");
+            let source = pasted.replace('\n', eol);
+            fs::write(&path, ide_vfs::encode(&source, encoding, encoding == "utf-16le").unwrap()).unwrap();
+            let mut defaults = f.docs.file_defaults();
+            defaults.native_to_ascii = true;
+            defaults.properties_fallback = encoding.into();
+            f.docs.set_file_defaults(defaults.clone());
+            let doc = f.docs.open(&path).unwrap();
+            assert_eq!(doc.text, displayed);
+
+            f.docs.replace_all(doc.id, pasted).unwrap();
+            f.docs.save(doc.id).unwrap();
+            assert_eq!(fs::read(&path).unwrap(), source.as_bytes(), "{encoding} {eol:?}");
+            assert_eq!(f.docs.snapshot(doc.id).unwrap().text, pasted);
+            assert!(!f.docs.is_dirty(doc.id).unwrap());
+            f.docs.on_disk_changed(std::slice::from_ref(&path));
+            assert_eq!(f.docs.snapshot(doc.id).unwrap().text, pasted, "own saves do not reload");
+
+            f.docs.close(doc.id);
+            let reopened = f.docs.open(&path).unwrap();
+            assert_eq!(reopened.text, displayed);
+            // An edit followed by its inverse preserves the original escape casing.
+            f.docs.replace_all(reopened.id, pasted).unwrap();
+            f.docs.replace_all(reopened.id, displayed).unwrap();
+            f.docs.save(reopened.id).unwrap();
+            assert_eq!(fs::read(&path).unwrap(), source.as_bytes());
+
+            let external = format!("{source}test.key4=\\uD83D\\uDE00{eol}");
+            fs::write(&path, &external).unwrap();
+            f.docs.on_disk_changed(std::slice::from_ref(&path));
+            assert_eq!(f.docs.snapshot(reopened.id).unwrap().text, format!("{displayed}test.key4=😀\n"));
+            defaults.native_to_ascii = false;
+            f.docs.set_file_defaults(defaults.clone());
+            f.docs.reload_properties();
+            assert_eq!(f.docs.snapshot(reopened.id).unwrap().text, external.replace("\r\n", "\n"));
+            defaults.native_to_ascii = true;
+            f.docs.set_file_defaults(defaults);
+            f.docs.reload_properties();
+            assert_eq!(f.docs.snapshot(reopened.id).unwrap().text, format!("{displayed}test.key4=😀\n"));
+            assert_eq!(fs::read_to_string(&path).unwrap(), external);
+        }
+    }
+}
+
 #[test]
 fn properties_toggle_reloads_only_clean_properties_and_pins_dirty_codec() {
    let f = fixture();
@@ -0,0 +1,119 @@
+/** Docking agent conversations between the editor and the Agents tool window by drag & drop. */
+import { expect, test, type Page } from "@playwright/test";
+
+const TASK = {
+  id: "t1",
+  title: "Repro task",
+  status: "ready" as const,
+  isolation: "local" as const,
+  provider: "codex",
+  model: null,
+  cwd: "/dev/acme-api",
+  branch: null,
+  base: null,
+  baseCommit: null,
+  error: null,
+  createdMs: 0,
+  updatedMs: 0,
+  config: [],
+  commands: [],
+  usage: null,
+  queue: [],
+};
+
+/** Seeds one task in the agents store (no backend in plain-browser mode) and docks it. */
+async function seedAndDock(page: Page) {
+  await page.evaluate(async (task) => {
+    // Paths go through variables: knip can't resolve these browser-absolute URLs.
+    const storePath = "/src/features/agents/store.ts";
+    const store = await import(storePath);
+    store.useAgents.setState({
+      loaded: true,
+      error: null,
+      providers: [],
+      tasks: new Map([[task.id, task]]),
+      unread: new Set(),
+      docked: null,
+    });
+    store.dockTask(task.id);
+  }, TASK);
+  await page.locator("span[title='Repro task']").first().waitFor();
+}
+
+test("drags the docked conversation back onto the editor", async ({ page }) => {
+  await page.goto("/");
+  await page.getByRole("tree", { name: "Project" }).waitFor();
+  // An editor pane, so the session tab has a content drop target to land on.
+  await page.getByRole("treeitem", { name: "README.md", exact: true }).dblclick();
+  await page.getByRole("tab", { name: "README.md" }).waitFor();
+  await seedAndDock(page);
+
+  const title = page.locator("span[title='Repro task']").first();
+  const to = await page.getByRole("tabpanel").first().boundingBox();
+  const from = await title.boundingBox();
+  await page.mouse.move(from!.x + from!.width / 2, from!.y + from!.height / 2);
+  await page.mouse.down();
+  await page.mouse.move(to!.x + to!.width / 2, to!.y + to!.height / 2, { steps: 10 });
+  await page.mouse.up();
+
+  await expect(page.getByRole("tab", { name: "Repro task" })).toBeVisible();
+  await expect(page.getByRole("tree", { name: "Agent tasks" })).toBeVisible();
+});
+
+test("drags the docked conversation back onto the empty editor", async ({ page }) => {
+  await page.goto("/");
+  await page.getByRole("tree", { name: "Project" }).waitFor();
+  // Docking closes the session tab; with no other tabs the editor is empty and
+  // must still take the drop (regression: the empty state had no drop target).
+  await seedAndDock(page);
+  await expect(page.locator("[data-editor-area] [role='tabpanel']")).toHaveCount(0);
+
+  const title = page.locator("span[title='Repro task']").first();
+  const to = await page.getByText("Drop files here to open them").boundingBox();
+  const from = await title.boundingBox();
+  await page.mouse.move(from!.x + from!.width / 2, from!.y + from!.height / 2);
+  await page.mouse.down();
+  await page.mouse.move(to!.x + to!.width / 2, to!.y + to!.height / 2, { steps: 10 });
+  await page.mouse.up();
+
+  await expect(page.getByRole("tab", { name: "Repro task" })).toBeVisible();
+});
+
+test("docks a session tab dropped on the tool window", async ({ page }) => {
+  await page.goto("/");
+  await page.getByRole("tree", { name: "Project" }).waitFor();
+  await page.getByRole("treeitem", { name: "README.md", exact: true }).dblclick();
+  await page.getByRole("tab", { name: "README.md" }).waitFor();
+  await page.evaluate(async (task) => {
+    const storePath = "/src/features/agents/store.ts";
+    const modelPath = "/src/features/agents/model.ts";
+    const contributionsPath = "/src/workbench/contributions.ts";
+    const store = await import(storePath);
+    const { TOOL_WINDOW } = await import(modelPath);
+    const { toolWindowService } = await import(contributionsPath);
+    store.useAgents.setState({
+      loaded: true,
+      error: null,
+      providers: [],
+      tasks: new Map([[task.id, task]]),
+      unread: new Set(),
+      docked: null,
+    });
+    toolWindowService().show(TOOL_WINDOW, true);
+    store.openTask(task.id);
+  }, TASK);
+  await page.getByRole("tab", { name: "Repro task" }).waitFor();
+
+  const tab = page.getByRole("tab", { name: "Repro task" });
+  const to = await page.getByRole("tree", { name: "Agent tasks" }).boundingBox();
+  const from = await tab.boundingBox();
+  await page.mouse.move(from!.x + from!.width / 2, from!.y + from!.height / 2);
+  await page.mouse.down();
+  await page.mouse.move(to!.x + to!.width / 2, to!.y + to!.height / 2, { steps: 10 });
+  await page.mouse.up();
+
+  // Docked: the tab closes and the tool window gives itself to the conversation.
+  await expect(page.getByRole("tab", { name: "Repro task" })).toHaveCount(0);
+  await expect(page.getByRole("tree", { name: "Agent tasks" })).toHaveCount(0);
+  await expect(page.locator("span[title='Repro task']").first()).toBeVisible();
+});
@@ -0,0 +1,74 @@
+{
+  "languages": [
+    "xml",
+    "html",
+    "vue",
+    "svelte",
+    "css",
+    "java",
+    "rust",
+    "typescript",
+    "python",
+    "csharp",
+    "sql",
+    "clojure",
+    "erlang",
+    "bat",
+    "ocaml",
+    "fsharp",
+    "haskell",
+    "lua",
+    "cmake",
+    "powershell",
+    "julia",
+    "ruby"
+  ],
+  "markers": [
+    {
+      "start": "region Name",
+      "end": "endregion",
+      "name": "Name"
+    },
+    {
+      "start": "region要折叠的内容",
+      "end": "endregion",
+      "name": "要折叠的内容"
+    },
+    {
+      "start": "#region \"Quoted name\"",
+      "end": "#endregion",
+      "name": "Quoted name"
+    },
+    {
+      "start": "REGION Mixed case",
+      "end": "ENDREGION",
+      "name": "Mixed case"
+    },
+    {
+      "start": "region",
+      "end": "endregion",
+      "name": ""
+    },
+    {
+      "start": "<editor-fold desc=\"Head 内容\">",
+      "end": "</editor-fold>",
+      "name": "Head 内容"
+    },
+    {
+      "start": "<editor-fold>",
+      "end": "</editor-fold>",
+      "name": ""
+    }
+  ],
+  "invalid": [
+    "regional Name",
+    "regions.push(x)",
+    "endregionFoo",
+    "<editor-folder>",
+    "</editor-folder>",
+    "the region below",
+    "region_name",
+    "<editor-fold",
+    "</editor-fold"
+  ]
+}
@@ -1,5 +1,6 @@
 id = "css"
 name = "CSS"
+formatter = { tool = "prettier", parser = "css", range = false }
 extensions = ["css", "pcss", "postcss"]
 block-comment = ["/*", "*/"]
 indent = { tab-size = 2, insert-spaces = true }
@@ -1,5 +1,6 @@
 id = "graphql"
 name = "GraphQL"
+formatter = { tool = "prettier", parser = "graphql", range = true }
 extensions = ["graphql", "graphqls", "gql"]
 line-comment = "#"
 indent = { tab-size = 2, insert-spaces = true }