fix(navigation): show usages on a declaration a plugin's index links elsewhere

A plugin's document index can link a declaration's name elsewhere: MyBatis Duo links a mapper method to its XML statement. Go to Declaration followed such a link at once, in the editor and in the host, so ⌘B on the method jumped to the XML instead of showing its usages as it does on any declaration (and did for plugins that answer through a definition provider). When the syntax tree puts the caret on a declaration's name, the link is no longer followed directly: the language server's answer comes along and the usages show, the plugin's target among them. Elsewhere plugin links are followed as before, without waiting for the language server.

Fixes #3207

.github/workflows/release-build.yml

@@ -78,7 +78,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with: { targets: "${{ matrix.target }}" }
       - uses: Swatinem/rust-cache@v2
-        with: { key: "${{ matrix.target }}" }
+        with: { key: "${{ matrix.target }}", cache-on-failure: true }
       - name: Linux deps
         if: runner.os == 'Linux'
         run: |
@@ -181,7 +181,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with: { targets: "${{ matrix.target }}" }
       - uses: Swatinem/rust-cache@v2
-        with: { key: "server-${{ matrix.target }}" }
+        with: { key: "server-${{ matrix.target }}", cache-on-failure: true }
       - name: musl toolchain
         if: runner.os == 'Linux'
         run: sudo apt-get update && sudo apt-get install -y musl-tools

Cargo.lock

@@ -4144,7 +4144,7 @@ checksum = "3d3067d79b975e8844ca9eb072e16b31c3c1c36928edf9c6789548c524d0d954"
 
 [[package]]
 name = "ide-agent"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4168,7 +4168,7 @@ dependencies = [
 
 [[package]]
 name = "ide-analysis"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ast-grep-core",
  "ide-core",
@@ -4182,7 +4182,7 @@ dependencies = [
 
 [[package]]
 name = "ide-android"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "serde",
@@ -4193,7 +4193,7 @@ dependencies = [
 
 [[package]]
 name = "ide-build"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "blake3",
  "chardetng",
@@ -4211,7 +4211,7 @@ dependencies = [
 
 [[package]]
 name = "ide-cli"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dirs 6.0.0",
  "serde",
@@ -4225,7 +4225,7 @@ dependencies = [
 
 [[package]]
 name = "ide-clipboard"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "gtk",
  "objc2 0.6.5",
@@ -4235,7 +4235,7 @@ dependencies = [
 
 [[package]]
 name = "ide-core"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4252,7 +4252,7 @@ dependencies = [
 
 [[package]]
 name = "ide-coverage"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "ide-run",
@@ -4266,7 +4266,7 @@ dependencies = [
 
 [[package]]
 name = "ide-dap"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "futures",
  "ide-core",
@@ -4288,11 +4288,12 @@ dependencies = [
  "tokio",
  "tracing",
  "tracing-subscriber",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
 name = "ide-db"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "base64 0.22.1",
  "bb8",
@@ -4328,7 +4329,7 @@ dependencies = [
 
 [[package]]
 name = "ide-docker"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "serde",
@@ -4341,7 +4342,7 @@ dependencies = [
 
 [[package]]
 name = "ide-extension"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "base64 0.22.1",
  "blake3",
@@ -4362,7 +4363,7 @@ dependencies = [
 
 [[package]]
 name = "ide-fonts"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "objc2-core-foundation",
  "objc2-core-text",
@@ -4374,7 +4375,7 @@ dependencies = [
 
 [[package]]
 name = "ide-github"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "ide-vcs",
@@ -4387,7 +4388,7 @@ dependencies = [
 
 [[package]]
 name = "ide-heap"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "criterion",
  "ide-core",
@@ -4405,7 +4406,7 @@ dependencies = [
 
 [[package]]
 name = "ide-host"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "base64 0.22.1",
  "blake3",
@@ -4476,7 +4477,7 @@ dependencies = [
 
 [[package]]
 name = "ide-http"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "ide-vfs",
@@ -4495,7 +4496,7 @@ dependencies = [
 
 [[package]]
 name = "ide-index"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "blake3",
  "criterion",
@@ -4517,7 +4518,7 @@ dependencies = [
 
 [[package]]
 name = "ide-jdwp"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-jvm-inspect",
  "proptest",
@@ -4529,7 +4530,7 @@ dependencies = [
 
 [[package]]
 name = "ide-jsonrpc"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "encoding_rs",
  "futures",
@@ -4546,7 +4547,7 @@ dependencies = [
 
 [[package]]
 name = "ide-jvm-attach"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "libc",
  "tempfile",
@@ -4555,7 +4556,7 @@ dependencies = [
 
 [[package]]
 name = "ide-jvm-inspect"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "futures",
  "serde",
@@ -4566,7 +4567,7 @@ dependencies = [
 
 [[package]]
 name = "ide-language"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "blake3",
  "criterion",
@@ -4623,7 +4624,7 @@ dependencies = [
 
 [[package]]
 name = "ide-lsp"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4651,7 +4652,7 @@ dependencies = [
 
 [[package]]
 name = "ide-mcp"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "bytes",
  "dunce",
@@ -4670,7 +4671,7 @@ dependencies = [
 
 [[package]]
 name = "ide-notebook"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "futures",
  "ide-core",
@@ -4693,7 +4694,7 @@ dependencies = [
 
 [[package]]
 name = "ide-plugin"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "blake3",
  "dunce",
@@ -4716,7 +4717,7 @@ dependencies = [
 
 [[package]]
 name = "ide-profiler"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "ide-jvm-attach",
@@ -4730,7 +4731,7 @@ dependencies = [
 
 [[package]]
 name = "ide-remote"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dunce",
  "futures",
@@ -4750,7 +4751,7 @@ dependencies = [
 
 [[package]]
 name = "ide-run"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4774,7 +4775,7 @@ dependencies = [
 
 [[package]]
 name = "ide-scaffold"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "ide-tools",
@@ -4790,7 +4791,7 @@ dependencies = [
 
 [[package]]
 name = "ide-sdk"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dunce",
  "ide-core",
@@ -4811,7 +4812,7 @@ dependencies = [
 
 [[package]]
 name = "ide-search"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "criterion",
  "encoding_rs",
@@ -4832,7 +4833,7 @@ dependencies = [
 
 [[package]]
 name = "ide-spell"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "parking_lot",
@@ -4845,7 +4846,7 @@ dependencies = [
 
 [[package]]
 name = "ide-ssh"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dirs 6.0.0",
  "flate2",
@@ -4870,7 +4871,7 @@ dependencies = [
 
 [[package]]
 name = "ide-syntax"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "ide-language",
@@ -4885,7 +4886,7 @@ dependencies = [
 
 [[package]]
 name = "ide-terminal"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "ide-core",
  "libc",
@@ -4898,7 +4899,7 @@ dependencies = [
 
 [[package]]
 name = "ide-text"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "criterion",
  "ide-core",
@@ -4911,7 +4912,7 @@ dependencies = [
 
 [[package]]
 name = "ide-tools"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "flate2",
  "hex",
@@ -4932,7 +4933,7 @@ dependencies = [
 
 [[package]]
 name = "ide-vcs"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "blake3",
  "dunce",
@@ -4953,7 +4954,7 @@ dependencies = [
 
 [[package]]
 name = "ide-vfs"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "chardetng",
  "dunce",
@@ -4977,7 +4978,7 @@ dependencies = [
 
 [[package]]
 name = "ide-web"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "dirs 6.0.0",
  "ide-core",
@@ -4993,7 +4994,7 @@ dependencies = [
 
 [[package]]
 name = "ide-workspace"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "blake3",
  "dunce",
@@ -6594,7 +6595,7 @@ dependencies = [
 
 [[package]]
 name = "openidea"
-version = "0.1.43"
+version = "0.1.44"
 dependencies = [
  "base64 0.22.1",
  "blake3",

Cargo.toml

@@ -5,7 +5,7 @@ members = ["crates/*", "src-tauri"]
 exclude = ["sdk", "plugins"]
 
 [workspace.package]
-version = "0.1.43"
+version = "0.1.44"
 edition = "2024"
 rust-version = "1.96"
 license = "Apache-2.0"

README.md

@@ -9,6 +9,10 @@
   The IDE you know, rebuilt in Rust.
 </p>
 
+<p align="center">
+  English · <a href="README.zh-CN.md">简体中文</a>
+</p>
+
 <p align="center">
   <a href="https://github.com/l0ng-ai/openidea/releases/latest"><b>Download</b></a>
   &nbsp;·&nbsp;
@@ -19,8 +23,6 @@
   <a href="#plugins">Plugins</a>
   &nbsp;·&nbsp;
   <a href="#community">Community</a>
-  &nbsp;·&nbsp;
-  <a href="#sponsor">Sponsor</a>
 </p>
 
 https://github.com/user-attachments/assets/234dd54c-1255-4b3a-b35c-533d78d737c0
@@ -70,17 +72,6 @@ the [official plugins](plugins/official). The plugin API is still a preview.
 
 - Contributing: see [CONTRIBUTING.md](CONTRIBUTING.md) and the [contributor docs](https://openidea.sh/en/contribute/setup).
 
-## Sponsor
-
-If OpenIDEA saves you time, you can support its development with Alipay or WeChat Pay.
-
-<table>
-  <tr>
-    <td align="center"><img src=".github/assets/sponsor-alipay.png" alt="Alipay QR code" width="200"><br>Alipay</td>
-    <td align="center"><img src=".github/assets/sponsor-wechat.png" alt="WeChat Pay QR code" width="200"><br>WeChat Pay</td>
-  </tr>
-</table>
-
 ## License
 
 [Apache 2.0](LICENSE). Bundled third-party assets are listed in [`THIRD_PARTY_LICENSES.md`](THIRD_PARTY_LICENSES.md).

README.zh-CN.md

@@ -0,0 +1,88 @@
+<p align="center">
+  <picture>
+    <source media="(prefers-color-scheme: dark)" srcset="src-tauri/icons/source/openidea-wordmark-dark.svg">
+    <img src="src-tauri/icons/source/openidea-wordmark.svg" alt="OpenIDEA" height="56">
+  </picture>
+</p>
+
+<p align="center">
+  你熟悉的 IDE，用 Rust 重新打造。
+</p>
+
+<p align="center">
+  <a href="README.md">English</a> · 简体中文
+</p>
+
+<p align="center">
+  <a href="https://github.com/l0ng-ai/openidea/releases/latest"><b>下载</b></a>
+  &nbsp;·&nbsp;
+  <a href="https://openidea.sh/zh">文档</a>
+  &nbsp;·&nbsp;
+  <a href="#性能对比">性能对比</a>
+  &nbsp;·&nbsp;
+  <a href="#插件">插件</a>
+  &nbsp;·&nbsp;
+  <a href="#社区">社区</a>
+  &nbsp;·&nbsp;
+  <a href="#赞助">赞助</a>
+</p>
+
+https://github.com/user-attachments/assets/234dd54c-1255-4b3a-b35c-533d78d737c0
+
+OpenIDEA 把 IntelliJ IDEA 的使用方式（快捷键、工具窗口、随处搜索的习惯）带到一个以 Rust
+为核心的原生桌面应用里。
+
+编辑器、代码洞察、调试器、Git、终端、数据库客户端和 HTTP 客户端，支持 60 多种语言。
+提供 macOS、Windows 和 Linux 版本。
+
+## 性能对比
+
+在缓存已预热的情况下打开 [freqtrade](https://github.com/freqtrade/freqtrade)（Python，约 770 个文件），
+取 5 次运行的中位数：
+
+|                       | OpenIDEA       | IntelliJ IDEA 2026.2.3 |
+| --------------------- | -------------- | ---------------------- |
+| 显示项目窗口          | **0.9 s**      | 3.1 s                  |
+| 就绪（CPU 平稳）      | **1.1 s**      | 13.2 s                 |
+| 内存（USS，所有进程） | **169 MB**     | 2011 MB                |
+| 就绪前消耗的 CPU 时间 | **2.4 s**      | 47.9 s                 |
+| 空闲 CPU              | 单核的 **4 %** | 单核的 7 %             |
+| 退出                  | **0.3 s**      | 5.9 s                  |
+
+测试使用 `main` 分支的 OpenIDEA release 构建，以及默认设置和插件的 IDEA，环境为 Windows 11、
+32 核 AMD、62 GB 内存。IDEA 对 Python 的分析更深入，所以两边的“就绪”并不代表完成了同样多的工作。
+两者都以相同方式从外部测量：可以用 [`perf/compare`](perf/compare) 在自己的机器和项目上复现。
+
+## 插件
+
+插件可以添加操作、补全、快速修复、工具窗口、自定义编辑器、主题、文件图标和语言。插件以沙箱化的
+WebAssembly 组件运行；主题、图标主题和语言无需编写代码。
+
+在“设置 › 插件”中安装，或用 `openidea-plugin new` 创建自己的插件：参见
+[编写 OpenIDEA 插件](https://openidea.sh/zh/plugins)和[官方插件](plugins/official)。插件 API 目前仍是预览版。
+
+## 社区
+
+- [Discord](https://discord.gg/2Zy4yn7gP)：提问、反馈和版本发布消息。
+- 微信群，扫码加入：
+
+  <img src=".github/assets/wechat-group.png" alt="微信群二维码" width="200">
+
+- 参与贡献：参见 [CONTRIBUTING.md](CONTRIBUTING.md) 和[贡献者文档](https://openidea.sh/zh/contribute/setup)。
+
+## 赞助
+
+如果 OpenIDEA 帮你节省了时间，可以通过支付宝或微信支付支持它的开发。
+
+<table>
+  <tr>
+    <td align="center"><img src=".github/assets/sponsor-alipay.png" alt="支付宝收款码" width="200"><br>支付宝</td>
+    <td align="center"><img src=".github/assets/sponsor-wechat.png" alt="微信支付收款码" width="200"><br>微信支付</td>
+  </tr>
+</table>
+
+## 许可证
+
+[Apache 2.0](LICENSE)。随附的第三方资源列在 [`THIRD_PARTY_LICENSES.md`](THIRD_PARTY_LICENSES.md) 中。
+
+<sub>与 JetBrains 无关联。IntelliJ IDEA 是 JetBrains s.r.o. 的商标。</sub>

crates/ide-agent/src/external.rs

@@ -3,11 +3,13 @@
 //!
 //! Only the native providers keep transcripts on disk in a readable form: Claude Code
 //! (`<config>/projects/*/<id>.jsonl`, see `native::claude::history`) and Codex
-//! (`<home>/.codex/sessions/**`, rollout files with a `session_meta` line).
+//! (`<home>/.codex/sessions/**`, rollout files with a `session_meta` line, named in
+//! `<home>/.codex/session_index.jsonl`).
 
 use super::native::claude::history;
 use serde::Serialize;
 use specta::Type;
+use std::collections::HashMap;
 use std::io::BufRead;
 use std::path::{Path, PathBuf};
 
@@ -206,11 +208,39 @@ fn rollout_files(dir: &Path, depth: usize, out: &mut Vec<PathBuf>) {
     }
 }
 
-/// Codex sessions of the project at `root`: `<home>/.codex/sessions/**`.
+/// Thread names Codex keeps in `session_index.jsonl`, by thread id. A rename adds a line,
+/// so the last one wins.
+fn codex_names(codex_home: &Path) -> HashMap<String, String> {
+    let Ok(file) = std::fs::File::open(codex_home.join("session_index.jsonl")) else { return HashMap::new() };
+    let mut names = HashMap::new();
+    for line in std::io::BufReader::new(file).lines() {
+        let Ok(line) = line else { break };
+        let Ok(v) = serde_json::from_str::<serde_json::Value>(&line) else { continue };
+        let id = v.get("id").and_then(serde_json::Value::as_str);
+        let name = v.get("thread_name").and_then(serde_json::Value::as_str).map(str::trim).filter(|n| !n.is_empty());
+        if let (Some(id), Some(name)) = (id, name) {
+            names.insert(id.to_owned(), name.to_owned());
+        }
+    }
+    names
+}
+
+/// Codex sessions of the project at `root`: `<home>/.codex/sessions/**`, titled by their
+/// thread names, else by their first prompts.
 pub fn codex_sessions(codex_home: &Path, root: &Path) -> Vec<ExternalSession> {
     let mut files = Vec::new();
     rollout_files(&codex_home.join("sessions"), 4, &mut files);
-    files.iter().filter_map(|p| codex_file(p)).filter(|s| in_project(s.cwd.as_deref(), root)).collect()
+    let mut sessions: Vec<ExternalSession> =
+        files.iter().filter_map(|p| codex_file(p)).filter(|s| in_project(s.cwd.as_deref(), root)).collect();
+    if !sessions.is_empty() {
+        let names = codex_names(codex_home);
+        for s in &mut sessions {
+            if let Some(name) = names.get(&s.session_id) {
+                s.title = short(name);
+            }
+        }
+    }
+    sessions
 }
 
 #[cfg(test)]
@@ -282,6 +312,16 @@ mod tests {
         assert_eq!((s.provider.as_str(), s.session_id.as_str()), ("codex", "thread-1"));
         assert_eq!(s.title, "add tests");
         assert_eq!(s.cwd.as_deref(), Some("/work/app"));
+
+        write(
+            &tmp.path().join("session_index.jsonl"),
+            &[
+                json!({"id": "thread-1", "thread_name": "Add tests", "updated_at": "t1"}),
+                json!({"id": "thread-2", "thread_name": "Other", "updated_at": "t1"}),
+                json!({"id": "thread-1", "thread_name": "Add parser tests", "updated_at": "t2"}),
+            ],
+        );
+        assert_eq!(codex_sessions(tmp.path(), Path::new("/work"))[0].title, "Add parser tests");
     }
 
     #[test]

crates/ide-agent/src/lib.rs

@@ -1097,6 +1097,8 @@ impl AgentManager {
                 title_renamed: s.title_renamed,
             }
         };
+        // Copying may have started the source's agent: it stops again once idle.
+        source.release_when_idle();
         let task = Task::restore(file, self.shared.clone());
         self.tasks.write().insert(task.id.clone(), task.clone());
         task.persist();
@@ -1166,6 +1168,8 @@ impl AgentManager {
         task.persist();
         self.shared.emit(AgentEvent::Truncated { task: id.to_owned(), length: cut as u32 });
         task.emit_task();
+        // Undoing may have started the agent: it stops again once idle.
+        task.release_when_idle();
         Ok(first)
     }
 

crates/ide-agent/src/native/claude/history.rs

@@ -158,6 +158,42 @@ pub(crate) fn title(entries: &[Value]) -> Option<String> {
         .map(str::to_owned)
 }
 
+/// Claude Code titles a session from the last 1000 characters of its text.
+const TITLE_SOURCE_CHARS: usize = 1000;
+/// Below this Claude Code gives no title without asking the model.
+const TITLE_SOURCE_MIN_CHARS: usize = 10;
+
+/// The conversation's own text to title the session after: the prompts and the replies,
+/// without the files attached to the prompts. `None` while there is too little.
+pub(super) fn title_source(entries: &[Value]) -> Option<String> {
+    let mut text = String::new();
+    for e in chain(entries, None) {
+        if !(is_turn_start(e) || kind(e) == "assistant") {
+            continue;
+        }
+        let blocks = match e.pointer("/message/content") {
+            Some(Value::String(s)) => vec![s.as_str()],
+            Some(Value::Array(blocks)) => blocks
+                .iter()
+                .filter(|b| b.get("type").and_then(Value::as_str) == Some("text"))
+                .filter_map(|b| b.get("text").and_then(Value::as_str))
+                .filter(|t| !t.starts_with("\n<context ref="))
+                .collect(),
+            _ => Vec::new(),
+        };
+        for block in blocks {
+            text.push_str(block);
+            text.push('\n');
+        }
+    }
+    let text = text.trim();
+    let len = text.chars().count();
+    if len < TITLE_SOURCE_MIN_CHARS {
+        return None;
+    }
+    Some(text.chars().skip(len.saturating_sub(TITLE_SOURCE_CHARS)).collect())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -219,6 +255,29 @@ mod tests {
         assert_eq!(cut(&c, 1), Ok(None));
     }
 
+    #[test]
+    fn titles_come_from_prompts_and_replies() {
+        let mut prompt = user("u1", None, "Fix the login form");
+        prompt["message"]["content"]
+            .as_array_mut()
+            .unwrap()
+            .push(json!({"type": "text", "text": "\n<context ref=\"file:///p/a.rs\">\nfn a() {}\n</context>"}));
+        let entries = vec![
+            prompt,
+            assistant(
+                "a1",
+                "u1",
+                json!([{"type": "thinking", "thinking": "hm"}, {"type": "text", "text": "Done."},
+                    {"type": "tool_use", "id": "t1", "name": "Bash", "input": {}}]),
+            ),
+            json!({"type": "user", "uuid": "r1", "parentUuid": "a1", "message": {"content": [{"type": "tool_result", "tool_use_id": "t1", "content": "out"}]}}),
+        ];
+        assert_eq!(title_source(&entries).as_deref(), Some("Fix the login form\nDone."));
+        assert_eq!(title_source(&[user("u1", None, "hi")]), None);
+        let long = "x".repeat(TITLE_SOURCE_CHARS + 5);
+        assert_eq!(title_source(&[user("u1", None, &long)]).map(|t| t.chars().count()), Some(TITLE_SOURCE_CHARS));
+    }
+
     #[test]
     fn project_directory_names() {
         assert_eq!(escape(Path::new("/private/tmp/a.b/c_d")), "-private-tmp-a-b-c-d");

crates/ide-agent/src/native/claude/mod.rs

@@ -191,6 +191,8 @@ struct State {
     limit_resets_ms: Option<f64>,
     terminal_only: Vec<String>,
     titled: bool,
+    /// A title is being read or generated.
+    titling: bool,
 }
 
 struct Turn {
@@ -365,6 +367,7 @@ impl Shim {
                 limit_resets_ms: None,
                 terminal_only: Vec::new(),
                 titled: false,
+                titling: false,
             }),
             cwd,
             starting: tokio::sync::Mutex::new(()),
@@ -583,11 +586,12 @@ impl Shim {
 impl super::Shim for Shim {
     fn attach(&self, client: Peer) {
         let _ = self.client.set(client.clone());
-        // The client went away: so do the processes.
-        let weak = self.me.clone();
+        // The client went away: so do the processes. Held until then: the connection drops
+        // its handler (this shim) as it closes, and the sessions would go without stopping.
+        let me = self.me.upgrade();
         tokio::spawn(async move {
             client.closed().await;
-            if let Some(me) = weak.upgrade() {
+            if let Some(me) = me {
                 me.closed.store(true, Ordering::Release);
                 let sessions: Vec<Arc<Session>> = me.sessions.lock().drain().map(|(_, s)| s).collect();
                 for s in sessions {
@@ -598,6 +602,15 @@ impl super::Shim for Shim {
     }
 }
 
+impl Drop for Session {
+    /// A session dropped without being stopped (the shim went away) takes its process along.
+    fn drop(&mut self) {
+        if let Some(p) = self.st.get_mut().proc.take() {
+            p.kill.cancel();
+        }
+    }
+}
+
 impl Session {
     fn shim(&self) -> Option<Arc<Shim>> {
         self.shim.upgrade()
@@ -1048,7 +1061,8 @@ impl Session {
                     } else if matches!(st.start, Start::New { .. }) {
                         st.start = Start::Resume { id: self.id.clone(), at: None };
                     }
-                    read_title = !st.titled;
+                    read_title = !st.titled && !st.titling;
+                    st.titling |= read_title;
                     if let Some(turn) = st.turn.as_ref()
                         && belongs(turn, &msg)
                     {
@@ -1073,13 +1087,29 @@ impl Session {
         }
     }
 
-    /// Sends the title Claude Code gave the session, once it has one.
+    /// Sends the session's title once it has one: the one in its transcript, or else one
+    /// Claude Code is asked for, as it titles no session run the way the Agent SDK runs it.
+    /// Without a title the next turn tries again.
     fn read_title(self: &Arc<Self>) {
         let me = self.clone();
-        tokio::task::spawn_blocking(move || {
-            let Some(title) = chain_title(&me) else { return };
-            me.st.lock().titled = true;
-            if let Some(shim) = me.shim() {
+        tokio::spawn(async move {
+            let reader = me.clone();
+            let entries = tokio::task::spawn_blocking(move || transcript_entries(&reader)).await.ok().flatten();
+            let mut title = entries.as_deref().and_then(history::title);
+            if title.is_none()
+                && let Some(source) = entries.as_deref().and_then(history::title_source)
+            {
+                title = me.generate_title(source).await;
+            }
+            {
+                let mut st = me.st.lock();
+                st.titling = false;
+                if title.is_none() {
+                    return;
+                }
+                st.titled = true;
+            }
+            if let (Some(title), Some(shim)) = (title, me.shim()) {
                 shim.notify(vec![Update {
                     session: me.id.clone(),
                     update: json!({ "sessionUpdate": "session_info_update", "title": title }),
@@ -1088,6 +1118,19 @@ impl Session {
         });
     }
 
+    /// A title Claude Code generates from `source`, also written to the transcript.
+    async fn generate_title(&self, source: String) -> Option<String> {
+        let proc = self.st.lock().proc.clone()?;
+        let request = json!({ "subtype": "generate_session_title", "description": source, "persist": true });
+        match proc.control(request).await {
+            Ok(r) => r.get("title").and_then(Value::as_str).map(str::trim).filter(|t| !t.is_empty()).map(str::to_owned),
+            Err(e) => {
+                tracing::debug!("generating a claude session title: {e}");
+                None
+            }
+        }
+    }
+
     async fn on_cli_request(self: &Arc<Self>, proc: &Arc<Proc>, msg: Value) {
         let id = msg.get("request_id").and_then(Value::as_str).unwrap_or_default().to_owned();
         let request = msg.get("request").cloned().unwrap_or_default();
@@ -1417,9 +1460,13 @@ fn strings(v: Option<&Value>) -> Vec<String> {
 
 /// The title in a session's transcript (or that of the session it continues).
 fn chain_title(session: &Session) -> Option<String> {
+    history::title(&transcript_entries(session)?)
+}
+
+fn transcript_entries(session: &Session) -> Option<Vec<Value>> {
     let shim = session.shim()?;
     let path = shim.transcript(&session.cwd, &session.id).filter(|p| p.exists())?;
-    history::title(&history::read(&path).ok()?)
+    history::read(&path).ok()
 }
 
 fn start_json(start: &Start) -> Value {

crates/ide-agent/src/native/claude/tests.rs

@@ -311,6 +311,8 @@ struct Replay {
     sent: Arc<Mutex<Vec<Vec<Value>>>>,
     launched: Mutex<Vec<Vec<String>>>,
     errors: Arc<Mutex<Vec<String>>>,
+    /// Each process's kill token.
+    kills: Mutex<Vec<CancellationToken>>,
 }
 
 impl Cli for Replay {
@@ -331,6 +333,7 @@ impl Cli for Replay {
         let (shim_in, cli_in) = tokio::io::duplex(1 << 20);
         let (mut cli_out, shim_out) = tokio::io::duplex(1 << 20);
         let kill = CancellationToken::new();
+        self.kills.lock().push(kill.clone());
         let (sent, errors, token) = (self.sent.clone(), self.errors.clone(), kill.clone());
         sent.lock().push(Vec::new());
         tokio::spawn(async move {
@@ -421,14 +424,18 @@ impl Replayed {
     }
 }
 
-async fn replay(name: &str) -> Replayed {
-    let processes = load_fixture(name);
-    let cli = Arc::new(Replay {
+fn replay_cli(processes: Vec<Vec<Frame>>) -> Arc<Replay> {
+    Arc::new(Replay {
         processes: Mutex::new(processes.into()),
         sent: Arc::default(),
         launched: Mutex::default(),
         errors: Arc::default(),
-    });
+        kills: Mutex::default(),
+    })
+}
+
+async fn replay(name: &str) -> Replayed {
+    let cli = replay_cli(load_fixture(name));
     let (config, cwd) = (tempfile::tempdir().unwrap(), tempfile::tempdir().unwrap());
     let cwd_path = std::fs::canonicalize(cwd.path()).unwrap();
     let h =
@@ -461,6 +468,69 @@ async fn replay_simple() {
     assert_eq!(user["message"]["content"][0]["text"], "Reply with exactly: hello there");
 }
 
+/// The app closing the connection (an idle task released, archived or deleted) stops the
+/// CLI processes of its sessions, idle ones included.
+#[tokio::test(flavor = "multi_thread")]
+async fn closing_the_connection_stops_the_processes() {
+    let r = replay("simple").await;
+    assert!(r.cli.kills.lock().iter().all(|k| !k.is_cancelled()));
+    r.h.client.kill();
+    let kills = r.cli.kills.lock().clone();
+    tokio::time::timeout(Duration::from_secs(5), async {
+        for k in kills {
+            k.cancelled().await;
+        }
+    })
+    .await
+    .expect("every process was stopped");
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn sessions_without_a_title_get_one_generated() {
+    let mut processes = load_fixture("simple");
+    processes[0].extend([
+        Frame::Shim(json!({"type": "control_request", "request_id": "req_3",
+            "request": {"subtype": "generate_session_title"}})),
+        Frame::Cli(json!({"type": "control_response",
+            "response": {"subtype": "success", "request_id": "req_3", "response": {"title": "Say hello"}}})),
+    ]);
+    let cli = replay_cli(processes);
+    let (config, cwd) = (tempfile::tempdir().unwrap(), tempfile::tempdir().unwrap());
+    let cwd_path = std::fs::canonicalize(cwd.path()).unwrap();
+    let h = Harness::connect(
+        cli.clone(),
+        config.path().into(),
+        config.path().join("pending"),
+        cwd_path.clone(),
+        Vec::new(),
+    )
+    .await;
+    let session = h.new_session().await;
+    // The transcript Claude Code writes, without the title it gives sessions in a terminal.
+    let dir = config.path().join("projects").join(history::escape(&cwd_path));
+    std::fs::create_dir_all(&dir).unwrap();
+    let prompt = json!({"type": "user", "uuid": "u1", "parentUuid": null,
+        "message": {"role": "user", "content": "Reply with exactly: hello there"}});
+    std::fs::write(dir.join(format!("{session}.jsonl")), format!("{prompt}\n")).unwrap();
+
+    h.prompt(&session, "Reply with exactly: hello there").await.unwrap();
+    let mut titles = Vec::new();
+    for _ in 0..100 {
+        titles = h.updates(&session, "session_info_update");
+        if !titles.is_empty() {
+            break;
+        }
+        tokio::time::sleep(Duration::from_millis(20)).await;
+    }
+    assert!(cli.errors.lock().is_empty(), "{:?}", cli.errors.lock());
+    assert_eq!(titles.iter().map(|t| t["title"].clone()).collect::<Vec<_>>(), [json!("Say hello")]);
+    let sent = cli.sent.lock()[0].clone();
+    let request =
+        sent.iter().find(|m| m.pointer("/request/subtype") == Some(&json!("generate_session_title"))).unwrap();
+    assert_eq!(request["request"]["description"], "Reply with exactly: hello there");
+    assert_eq!(request["request"]["persist"], true);
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn replay_multi_turn() {
     let r = replay("multi_turn").await;
@@ -727,6 +797,7 @@ async fn a_stop_ahead_of_its_prompt_cancels_it() {
         sent: Arc::default(),
         launched: Mutex::default(),
         errors: Arc::default(),
+        kills: Mutex::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;
@@ -770,6 +841,7 @@ async fn a_failed_turn_reports_its_failure() {
             sent: Arc::default(),
             launched: Mutex::default(),
             errors: Arc::default(),
+            kills: Mutex::default(),
         });
         let (dir, cwd) = (tempfile::tempdir().unwrap(), tempfile::tempdir().unwrap());
         let h =

crates/ide-agent/src/native/codex/mod.rs

@@ -28,6 +28,9 @@ const OUTPUT_EVERY: Duration = Duration::from_millis(200);
 const EARLY_CANCEL: Duration = Duration::from_secs(1);
 /// How long the client's connection outlives codex.
 const EXIT_GRACE: Duration = Duration::from_millis(100);
+/// What a thread's name is asked for with, after its first turn.
+const NAME_PROMPT: &str = "Name this conversation for a list of tasks: a short title of at most six words, in the \
+    language the user writes in. Reply with the title only, without quotes or a closing period.";
 
 pub(crate) fn connect(
     spec: &ProviderSpec,
@@ -126,6 +129,10 @@ struct Thread {
     early_cancel: Option<Instant>,
     /// The latest agent message (a subagent's answer).
     answer: String,
+    /// The thread has a name.
+    named: bool,
+    /// A name is being asked for.
+    naming: bool,
 }
 
 struct PendingPrompt {
@@ -329,6 +336,7 @@ impl CodexShim {
         t.parent = None;
         t.settings = Some(settings);
         t.cwd = cwd;
+        t.named = thread.get("name").and_then(Value::as_str).is_some_and(|n| !n.trim().is_empty());
         (id, options)
     }
 
@@ -625,8 +633,9 @@ impl CodexShim {
                 Some(translate::plan(params))
             }),
             "thread/tokenUsage/updated" => self.with_thread(thread, |_, _| translate::usage(params)),
-            "thread/name/updated" => self.with_thread(thread, |_, _| {
+            "thread/name/updated" => self.with_thread(thread, |t, _| {
                 let title = params.get("threadName").and_then(Value::as_str)?;
+                t.named = true;
                 Some(json!({ "sessionUpdate": "session_info_update", "title": title }))
             }),
             "thread/started" => self.thread_started(params.get("thread").unwrap_or(&Value::Null)),
@@ -812,9 +821,10 @@ impl CodexShim {
         }
     }
 
-    fn turn_completed(&self, thread: &str, turn: &Value) {
+    fn turn_completed(self: &Arc<Self>, thread: &str, turn: &Value) {
         let id = turn.get("id").and_then(Value::as_str).unwrap_or_default();
-        let (parent, answer) = {
+        let completed = turn.get("status").and_then(Value::as_str) == Some("completed");
+        let (parent, answer, name) = {
             let mut state = self.state.lock();
             let Some(t) = state.threads.get_mut(thread) else { return };
             if t.turn.as_deref().is_none_or(|r| r == id) {
@@ -830,8 +840,15 @@ impl CodexShim {
                 let _ = p.done.send((turn.clone(), error.clone()));
             }
             let answer = std::mem::take(&mut t.answer);
-            (t.parent.clone(), (answer, error))
+            let name =
+                completed && !id.is_empty() && t.parent.is_none() && t.settings.is_some() && !t.named && !t.naming;
+            t.naming |= name;
+            (t.parent.clone(), (answer, error), name)
         };
+        if name {
+            let (shim, thread, turn) = (self.clone(), thread.to_owned(), id.to_owned());
+            self.runtime.spawn(async move { shim.name_thread(&thread, &turn).await });
+        }
         let Some(parent) = parent else { return };
         let (answer, error) = answer;
         let mut state_of = match turn.get("status").and_then(Value::as_str) {
@@ -853,6 +870,28 @@ impl CodexShim {
         }
     }
 
+    /// Names a thread from what it holds after `turn`, as codex leaves naming to its
+    /// clients; `thread/name/updated` brings the name back. Unnamed, the next turn tries again.
+    async fn name_thread(&self, thread: &str, turn: &str) {
+        let sample = json!({ "threadId": thread, "expectedTurnId": turn, "prompt": NAME_PROMPT, "effort": "low" });
+        let named = match self.call("thread/sample", sample).await {
+            Ok(r) => match r.get("text").and_then(Value::as_str).and_then(translate::thread_name) {
+                Some(name) => {
+                    self.call("thread/name/set", json!({ "threadId": thread, "name": name })).await.map(|_| ())
+                }
+                None => Err(error(codes::INTERNAL_ERROR, "codex gave no name")),
+            },
+            Err(e) => Err(e),
+        };
+        if let Err(e) = &named {
+            tracing::debug!("naming codex thread {thread}: {}", e.message);
+        }
+        if let Some(t) = self.state.lock().threads.get_mut(thread) {
+            t.naming = false;
+            t.named |= named.is_ok();
+        }
+    }
+
     /// Requests from codex: approvals and questions, asked as ACP permission requests.
     fn on_codex_request(&self, method: &str, params: &Value) -> Result<Value, (i64, String)> {
         let thread = params.get("threadId").and_then(Value::as_str).unwrap_or_default().to_owned();

crates/ide-agent/src/native/codex/tests.rs

@@ -535,8 +535,10 @@ async fn play<R: AsyncRead + Unpin, W: AsyncWrite + Unpin>(
                     .unwrap()
                     .unwrap_or_else(|| panic!("the shim closed before {frame}"));
                 let actual: Value = serde_json::from_str(&line).unwrap();
-                // Older recordings predate skill discovery; play an unsupported server.
-                if actual["method"] == "skills/list" && frame["method"] != "skills/list" {
+                // Older recordings predate skill discovery and thread naming; play an
+                // unsupported server.
+                let method = actual["method"].as_str().unwrap_or_default();
+                if matches!(method, "skills/list" | "thread/sample") && frame["method"] != method {
                     let reply = json!({ "id": actual["id"], "error": { "code": -32601, "message": "unsupported" } });
                     write.write_all(format!("{reply}\n").as_bytes()).await.unwrap();
                     continue;
@@ -574,7 +576,14 @@ async fn play<R: AsyncRead + Unpin, W: AsyncWrite + Unpin>(
 /// Runs `scenario` against its transcript; returns the ACP results, the client and
 /// the frames the shim sent.
 async fn replay(scenario: Scenario) -> (Results, Arc<Client>, Vec<Value>, Value) {
-    let t = load(scenario.file());
+    let (results, client, sent, meta, _codex) = replay_transcript(scenario, load(scenario.file())).await;
+    (results, client, sent, meta)
+}
+
+/// Both connections of a replay, which stay open while it is held.
+type CodexEnd = Box<dyn std::any::Any>;
+
+async fn replay_transcript(scenario: Scenario, t: Transcript) -> (Results, Arc<Client>, Vec<Value>, Value, CodexEnd) {
     let (ours, theirs) = tokio::io::duplex(1 << 20);
     let (tr, tw) = tokio::io::split(theirs);
     let client = Arc::new(Client::default());
@@ -590,8 +599,8 @@ async fn replay(scenario: Scenario) -> (Results, Arc<Client>, Vec<Value>, Value)
         .await
         .expect("the scenario finished");
     // Codex stays up until the scenario is over.
-    let (sent, _read, _write) = player.await.unwrap();
-    (results, client, sent, meta)
+    let (sent, read, write) = player.await.unwrap();
+    (results, client, sent, meta, Box::new((acp, read, write)))
 }
 
 fn sent<'a>(frames: &'a [Value], method: &str) -> Vec<&'a Value> {
@@ -801,6 +810,42 @@ async fn a_simple_turn_streams_reasoning_text_and_usage() {
     assert_eq!(info["title"], "Say hi");
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn an_unnamed_thread_is_named_after_its_first_turn() {
+    let mut t = load(Scenario::Simple.file());
+    t.frames.retain(|(_, f)| f["method"] != "thread/name/updated");
+    let thread = "01a18300-0000-7000-8000-000000000001";
+    t.frames.extend([
+        (true, json!({"id": 90, "method": "thread/sample"})),
+        (false, json!({"id": 90, "result": {"responseId": "r", "sourceTurnId": thread, "text": "\"Say hi.\"\n"}})),
+        (true, json!({"id": 91, "method": "thread/name/set"})),
+        (false, json!({"id": 91, "result": {}})),
+        (false, json!({"method": "thread/name/updated", "params": {"threadId": thread, "threadName": "Say hi"}})),
+    ]);
+    let (results, client, frames, _, _codex) = replay_transcript(Scenario::Simple, t).await;
+    let session = session_of(&results, "new");
+    let sample = &sent(&frames, "thread/sample")[0]["params"];
+    assert_eq!((sample["threadId"].as_str(), sample["expectedTurnId"].as_str()), (Some(thread), Some(thread)));
+    assert_eq!(sent(&frames, "thread/name/set")[0]["params"], json!({"threadId": thread, "name": "Say hi"}));
+    let mut info = Vec::new();
+    for _ in 0..100 {
+        info = client.of(&session).into_iter().filter(|u| u["sessionUpdate"] == "session_info_update").collect();
+        if !info.is_empty() {
+            break;
+        }
+        tokio::time::sleep(Duration::from_millis(20)).await;
+    }
+    assert_eq!(info.iter().map(|u| u["title"].clone()).collect::<Vec<_>>(), [json!("Say hi")]);
+}
+
+#[test]
+fn thread_names_are_the_first_line_of_the_reply() {
+    assert_eq!(thread_name("  \n“修复登录表单。”\nmore").as_deref(), Some("修复登录表单"));
+    assert_eq!(thread_name("**Fix the login form.**").as_deref(), Some("Fix the login form"));
+    assert_eq!(thread_name(" \n\"\" "), None);
+    assert_eq!(thread_name(&"x".repeat(100)).map(|n| n.chars().count()), Some(80));
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn settings_apply_to_the_next_turn() {
     let (results, client, frames, _) = replay(Scenario::MultiTurn).await;

crates/ide-agent/src/native/codex/translate.rs

@@ -612,6 +612,16 @@ pub(super) fn usage(params: &Value) -> Option<Value> {
     Some(json!({ "sessionUpdate": "usage_update", "used": used, "size": size }))
 }
 
+/// A thread name from the model's reply to the naming prompt: its first line, without
+/// quotes or a closing period. `None` when nothing is left.
+pub(super) fn thread_name(reply: &str) -> Option<String> {
+    const MAX_NAME: usize = 80;
+    let line = reply.lines().map(str::trim).find(|l| !l.is_empty())?;
+    let line = line.trim_matches(|c: char| matches!(c, '"' | '\'' | '`' | '“' | '”' | '「' | '」' | '*'));
+    let line = line.trim_end_matches(['.', '。']).trim();
+    (!line.is_empty()).then(|| line.chars().take(MAX_NAME).collect())
+}
+
 /// How a failed turn is reported.
 #[derive(Debug, PartialEq)]
 pub(super) enum Failure {

crates/ide-agent/src/tests.rs

@@ -2391,6 +2391,27 @@ async fn idle_agents_stop_and_resume_their_session_on_the_next_message() {
     assert!(live(&mgr, &task.id));
     mgr.shutdown();
 
+    // Undoing turns or copying the conversation starts a stopped agent: it stops again too.
+    let tmp = tempfile::tempdir().unwrap();
+    let agent = Arc::new(FakeAgent::default());
+    let mgr = manager(tmp.path(), agent.clone());
+    mgr.set_idle_release(Duration::from_millis(200));
+    let task = mgr.create(new()).await.unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    mgr.prompt(&task.id, text("again"), false).await.unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    tokio::time::sleep(Duration::from_millis(600)).await;
+    assert!(!live(&mgr, &task.id));
+    mgr.rollback(&task.id, 1).await.unwrap();
+    assert!(live(&mgr, &task.id));
+    tokio::time::sleep(Duration::from_millis(600)).await;
+    assert!(!live(&mgr, &task.id), "an agent started to undo turns stops too");
+    mgr.fork(&task.id, None).await.unwrap();
+    assert!(live(&mgr, &task.id));
+    tokio::time::sleep(Duration::from_millis(600)).await;
+    assert!(!live(&mgr, &task.id), "an agent started to copy the conversation stops too");
+    mgr.shutdown();
+
     // An agent that can't reload its session keeps running: stopping it would lose the conversation.
     let tmp = tempfile::tempdir().unwrap();
     let agent = Arc::new(FakeAgent { no_load: true, ..FakeAgent::default() });

crates/ide-agent/src/worktree.rs

@@ -225,6 +225,15 @@ fn same_file(a: &Path, b: &Path) -> bool {
     }
 }
 
+/// The bytes of `path` (`Some(None)`: no file there), or `None` when it is there but can't be read.
+fn existing(path: &Path) -> Option<Option<Vec<u8>>> {
+    match std::fs::read(path) {
+        Ok(bytes) => Some(Some(bytes)),
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Some(None),
+        Err(_) => None,
+    }
+}
+
 fn crlf_to_lf(bytes: &[u8]) -> Vec<u8> {
     let mut out = Vec::with_capacity(bytes.len());
     for (i, &b) in bytes.iter().enumerate() {
@@ -411,25 +420,31 @@ pub(crate) fn accept(
     let copyable = |rel: &str| task_side.allows(rel) && checkout_side.allows(rel);
     let renamed_from: BTreeMap<String, String> =
         repo.diff_with_worktree(base)?.into_iter().filter_map(|f| Some((f.path, f.old_path?))).collect();
-    // Brings one path of the checkout to the task's version, unless the checkout changed it itself.
-    let apply = |rel: &str| -> IdeResult<bool> {
-        let local = local_root.join(rel);
+    // The task's version of one path of the checkout (`Some(None)`: absent there), or `None` when
+    // the checkout changed it itself.
+    let target = |rel: &str| -> IdeResult<Option<Option<Vec<u8>>>> {
         let in_task = repo.root().join(rel);
-        let base_bytes = repo.file_bytes_at(&in_task, Some(base))?;
         let current = std::fs::read(&in_task).ok();
-        let local_bytes = std::fs::read(&local).ok();
+        // A file there that can't be read is the checkout's own: never written over.
+        let Some(local_bytes) = existing(&local_root.join(rel)) else { return Ok(None) };
         if local_bytes == current {
-            return Ok(true);
+            return Ok(Some(current));
         }
+        let base_bytes = repo.file_bytes_at(&in_task, Some(base))?;
         // The checkout may hold the committed LF text with CRLF line ends (`core.autocrlf`).
         let unchanged = match (&local_bytes, &base_bytes) {
             (Some(now), Some(at_base)) => now == at_base || crlf_to_lf(now) == *at_base,
             (now, at_base) => now == at_base,
         };
-        if !unchanged {
-            return Ok(false);
+        Ok(unchanged.then_some(current))
+    };
+    // Puts `bytes` (`None`: nothing) at `rel` of the checkout.
+    let write = |rel: &str, bytes: Option<Vec<u8>>| -> IdeResult<()> {
+        let local = local_root.join(rel);
+        if std::fs::read(&local).ok() == bytes {
+            return Ok(());
         }
-        match current {
+        match bytes {
             Some(bytes) => {
                 if let Some(parent) = local.parent() {
                     std::fs::create_dir_all(parent)?;
@@ -441,6 +456,12 @@ pub(crate) fn accept(
                 _ => {}
             },
         }
+        Ok(())
+    };
+    // Brings one path of the checkout to the task's version, unless the checkout changed it itself.
+    let apply = |rel: &str| -> IdeResult<bool> {
+        let Some(bytes) = target(rel)? else { return Ok(false) };
+        write(rel, bytes)?;
         Ok(true)
     };
     let mut accepted = Vec::with_capacity(changes.len());
@@ -466,8 +487,9 @@ pub(crate) fn accept(
         // A case-only rename (`a.txt` → `A.txt`). Where the disk resolves both
         // spellings to one file it is renamed in place and `apply` then refreshes
         // the content. On a case-sensitive disk the two names are different files:
-        // the old one's unchanged-ness (it is the file the checkout had) decides —
-        // then the task's version lands at the new name and the old one goes.
+        // both are checked before either changes — the old one must be the file the
+        // checkout had, the new one absent or already the task's — then the task's
+        // version lands at the new name before the old one goes.
         let case_only =
             old.is_some_and(|o| o != &change.rel_path && o.to_lowercase() == change.rel_path.to_lowercase());
         if case_only {
@@ -476,20 +498,18 @@ pub(crate) fn accept(
             if same_file(&old_path, &new_path) {
                 std::fs::rename(&old_path, &new_path)?;
             } else {
-                if !apply(old)? {
+                let Some(old_target) = target(old)? else {
                     skipped.push(skip(old));
                     continue;
+                };
+                let task_bytes = std::fs::read(repo.root().join(&change.rel_path)).ok();
+                let at_new = existing(&new_path);
+                if at_new.as_ref().is_none_or(|at_new| at_new.is_some() && *at_new != task_bytes) {
+                    skipped.push(skip(&change.rel_path));
+                    continue;
                 }
-                // `apply(old)` removed the old file (the task's tree has it only at
-                // the new name); now write that version under the new name. `apply`
-                // can't do it — it reads the new name's own base/absence — so the
-                // write is open-coded from the same task bytes `apply` would use.
-                if let Ok(bytes) = std::fs::read(repo.root().join(&change.rel_path)) {
-                    if let Some(parent) = new_path.parent() {
-                        std::fs::create_dir_all(parent)?;
-                    }
-                    std::fs::write(&new_path, bytes)?;
-                }
+                write(&change.rel_path, task_bytes)?;
+                write(old, old_target)?;
                 accepted.push(change.rel_path.clone());
                 continue;
             }
@@ -960,6 +980,41 @@ mod tests {
         assert_eq!(names, ["A.txt"]);
     }
 
+    #[test]
+    fn a_case_only_rename_keeps_a_file_the_checkout_has_at_the_new_name() {
+        let (_tmp, repo, created) = accept_repo();
+        std::fs::write(repo.join("A.txt"), "mine\n").unwrap();
+        if std::fs::read_to_string(repo.join("a.txt")).unwrap() == "mine\n" {
+            eprintln!("this disk doesn't tell a.txt from A.txt; nothing to check");
+            return;
+        }
+        git(&created.path, &["mv", "a.txt", "A.txt"]);
+        let changes = listed(&created.path, &created.base_commit);
+        let outcome = accept(&repo, &created.path, &created.base_commit, &changes).unwrap();
+        assert_eq!(outcome.skipped.iter().map(|s| s.path.as_str()).collect::<Vec<_>>(), ["A.txt"]);
+        assert_eq!(std::fs::read_to_string(repo.join("A.txt")).unwrap(), "mine\n");
+        assert_eq!(std::fs::read_to_string(repo.join("a.txt")).unwrap(), "one\ntwo\n");
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn accept_leaves_a_checkout_file_it_cannot_read() {
+        use std::os::unix::fs::PermissionsExt;
+        let (_tmp, repo, created) = accept_repo();
+        std::fs::write(created.path.join("new.txt"), "task\n").unwrap();
+        std::fs::write(repo.join("new.txt"), "mine\n").unwrap();
+        std::fs::set_permissions(repo.join("new.txt"), std::fs::Permissions::from_mode(0o200)).unwrap();
+        if std::fs::read(repo.join("new.txt")).is_ok() {
+            eprintln!("running as a user that reads any file; nothing to check");
+            return;
+        }
+        let changes = listed(&created.path, &created.base_commit);
+        let outcome = accept(&repo, &created.path, &created.base_commit, &changes).unwrap();
+        std::fs::set_permissions(repo.join("new.txt"), std::fs::Permissions::from_mode(0o644)).unwrap();
+        assert_eq!(outcome.skipped.iter().map(|s| s.path.as_str()).collect::<Vec<_>>(), ["new.txt"]);
+        assert_eq!(std::fs::read_to_string(repo.join("new.txt")).unwrap(), "mine\n");
+    }
+
     #[cfg(windows)]
     #[test]
     fn accept_does_not_write_into_the_checkouts_git_folder_through_its_short_name() {

crates/ide-build/src/compile/mod.rs

@@ -12,7 +12,8 @@ mod up_to_date;
 pub use fingerprint::{LaunchFingerprint, launch_fingerprint, menu_fingerprint};
 pub use launch_resources::process_launch_resources;
 pub use single::{
-    SingleFileTarget, compile_file_plan, find_javac, javac_step, single_file_classpath, single_file_target,
+    SingleFileTarget, compile_file_plan, find_javac, javac_step, module_classpath, single_file_classpath,
+    single_file_target,
 };
 pub use up_to_date::{menu_up_to_date, record_menu_build};
 

crates/ide-build/src/compile/single.rs

@@ -4,12 +4,21 @@
 //! walks the whole reactor; compiling one file only needs that file's module
 //! outputs plus its dependency classpath, which is much faster to assemble.
 use super::*;
+use serde::{Deserialize, Serialize};
 use std::fs;
 use std::process::Command as ProcCommand;
 
 /// Output file of the `dependency:build-classpath` probe, relative to each module.
 const CP_FILE: &str = "target/ide-compile-cp.txt";
 
+/// The resolved dependency classpath for one module and scope, tied to the same
+/// inputs as its launch build so POM, JDK, settings and profile changes invalidate it.
+#[derive(Debug, Deserialize, Serialize)]
+struct CachedClasspath {
+    fingerprint: LaunchFingerprint,
+    classpath: String,
+}
+
 /// A `.java` source and the module build that compiles it.
 pub struct SingleFileTarget {
     /// Absolute module directory.
@@ -64,6 +73,28 @@ pub fn single_file_target(root: &Path, model: &BuildModel, file: &Path) -> IdeRe
     Ok(SingleFileTarget { module, test, out_dir, top: top.clone(), pl, java_version: project.java_version })
 }
 
+/// The Maven reactor target for a launch module whose source file is not known yet.
+fn module_target(root: &Path, model: &BuildModel, module: &Path, test: bool) -> IdeResult<SingleFileTarget> {
+    let Some(m) = &model.maven else {
+        return Err(IdeError::not_found("no linked Maven project found for module"));
+    };
+    let module = if module.is_absolute() { module.to_path_buf() } else { root.join(module) };
+    let project = m
+        .projects
+        .iter()
+        .find(|p| root.join(&p.dir) == module)
+        .ok_or_else(|| IdeError::not_found("no linked Maven project found for module"))?;
+    if project.packaging == "pom" {
+        return Err(IdeError::not_found("the launch module is a Maven aggregator without sources"));
+    }
+    let top = maven_reactor(m, &project.dir)
+        .ok_or_else(|| IdeError::not_found("no linked Maven reactor found for module"))?;
+    let top_dir = subdir(root, &top.dir);
+    let pl = module.strip_prefix(&top_dir).map(|r| r.to_string_lossy().replace('\\', "/")).unwrap_or_default();
+    let out_dir = module.join("target").join(if test { "test-classes" } else { "classes" });
+    Ok(SingleFileTarget { module, test, out_dir, top: top.clone(), pl, java_version: project.java_version })
+}
+
 /// `javac` for the module: its `JAVA_HOME`, else `PATH`.
 pub fn find_javac(env: &BTreeMap<String, String>) -> String {
     let home = env.get("JAVA_HOME").map(Path::new);
@@ -78,6 +109,88 @@ pub fn find_javac(env: &BTreeMap<String, String>) -> String {
 /// `mvn dependency:build-classpath` (which resolves without compiling anything,
 /// so `-am` stays cheap). Entries are platform-separated (`;` on Windows).
 pub fn single_file_classpath(root: &Path, model: &BuildModel, target: &SingleFileTarget) -> IdeResult<String> {
+    classpath(root, model, target, "test", false)
+}
+
+/// Runtime (or test) dependency classpath for a launch module.
+///
+/// The Java language server runs on its own JDK, so its Maven model can select a
+/// different JDK profile and dependency classifier than the project launch. Use the
+/// same Maven process that builds the module instead.
+pub fn module_classpath(
+    root: &Path,
+    model: &BuildModel,
+    module: &Path,
+    test: bool,
+    local_repo: Option<PathBuf>,
+    cache: &Path,
+    cancel: &ide_core::CancellationToken,
+) -> IdeResult<String> {
+    let target = module_target(root, model, module, test)?;
+    let fingerprint = launch_fingerprint(root, model, &target.module, test, local_repo, cancel)?;
+    let cache_path = classpath_cache_path(root, cache, &target.module, test);
+    if let (Some(fingerprint), Some(path)) = (&fingerprint, &cache_path)
+        && let Ok(bytes) = fs::read(path)
+        && let Ok(cached) = serde_json::from_slice::<CachedClasspath>(&bytes)
+        && cached.fingerprint == *fingerprint
+        && classpath_entries_exist(root, &cached.classpath)
+    {
+        return Ok(cached.classpath);
+    }
+    let classpath = classpath(root, model, &target, if test { "test" } else { "runtime" }, true)?;
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    if let (Some(fingerprint), Some(path)) = (fingerprint, cache_path) {
+        let cached = CachedClasspath { fingerprint, classpath: classpath.clone() };
+        if let Err(error) = cache_classpath(&path, &cached) {
+            tracing::debug!(path = %path.display(), %error, "Cannot cache the Java launch classpath");
+        }
+    }
+    Ok(classpath)
+}
+
+/// One cache file per module and scope. Mirroring the module path keeps nested
+/// modules and their different dependency scopes from overwriting each other.
+fn classpath_cache_path(root: &Path, cache: &Path, module: &Path, test: bool) -> Option<PathBuf> {
+    let relative = module.strip_prefix(root).ok()?;
+    let mut path = cache.join("java-launch/classpaths");
+    path.push(if relative.as_os_str().is_empty() { Path::new("_root") } else { relative });
+    path.push(if test { "test.json" } else { "runtime.json" });
+    Some(path)
+}
+
+/// Best-effort cache persistence. A failed write only costs one later Maven
+/// probe, so the launch still succeeds even when the cache directory is unusable.
+fn cache_classpath(path: &Path, cached: &CachedClasspath) -> IdeResult<()> {
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)?;
+    }
+    fs::write(path, serde_json::to_vec(cached).map_err(|e| IdeError::internal(e.to_string()))?)?;
+    Ok(())
+}
+
+/// A cache entry stays valid while every file exists. Maven also emits reactor
+/// output directories for modules with no classes, which may legitimately never be
+/// created; the launch snapshot already supplies the module's classes in that case.
+fn classpath_entries_exist(root: &Path, classpath: &str) -> bool {
+    // Temp directories on macOS are commonly reached through `/var`, while Maven
+    // reports the canonical `/private/var` path. Compare against both spellings.
+    let canonical_root = dunce::canonicalize(root).unwrap_or_else(|_| root.to_path_buf());
+    std::env::split_paths(classpath).all(|entry| {
+        entry.exists()
+            || ((entry.starts_with(root) || entry.starts_with(&canonical_root))
+                && (entry.ends_with(Path::new("target/classes")) || entry.ends_with(Path::new("target/test-classes"))))
+    })
+}
+
+fn classpath(
+    root: &Path,
+    model: &BuildModel,
+    target: &SingleFileTarget,
+    scope: &str,
+    compile_first: bool,
+) -> IdeResult<String> {
     let mut entries: Vec<String> = Vec::new();
     // The module's own classes first: the file almost always uses classes next to it.
     let own: &[&str] = if target.test { &["target/test-classes", "target/classes"] } else { &["target/classes"] };
@@ -110,7 +223,14 @@ pub fn single_file_classpath(root: &Path, model: &BuildModel, target: &SingleFil
         args.extend(["-pl", target.pl.as_str(), "-am"]);
     }
     let output_arg = format!("-Dmdep.outputFile={probe}");
-    args.extend(["dependency:build-classpath", output_arg.as_str(), "-Dmdep.includeScope=test", "-q"]);
+    let scope_arg = format!("-Dmdep.includeScope={scope}");
+    // A launch build may only have reached `compile`. Running `compile` in this
+    // same Maven session lets the dependency plugin resolve Reactor siblings from
+    // their target/classes without paying for package-phase plugins.
+    if compile_first {
+        args.push("compile");
+    }
+    args.extend(["dependency:build-classpath", output_arg.as_str(), scope_arg.as_str(), "-q"]);
     let top_dir = subdir(root, &target.top.dir);
     let status = ProcCommand::new(&target.top.command)
         .args(&args)
@@ -119,8 +239,10 @@ pub fn single_file_classpath(root: &Path, model: &BuildModel, target: &SingleFil
         .output()
         .map_err(|e| IdeError::internal(format!("cannot resolve the compile classpath: {e}")))?;
     if !status.status.success() {
+        let stdout = String::from_utf8_lossy(&status.stdout);
         let stderr = String::from_utf8_lossy(&status.stderr);
-        let tail: Vec<&str> = stderr.lines().filter(|l| !l.trim().is_empty()).collect();
+        // Maven reports reactor/dependency failures on stdout, not only stderr.
+        let tail: Vec<&str> = stdout.lines().chain(stderr.lines()).filter(|l| !l.trim().is_empty()).collect();
         let tail = tail.iter().rev().take(5).rev().cloned().collect::<Vec<_>>().join("\n");
         return Err(IdeError::internal(format!("cannot resolve the compile classpath:\n{tail}")));
     }
@@ -305,7 +427,7 @@ mod tests {
         let script = root.join("mvnw");
         fs::write(
             &script,
-            "#!/bin/sh\npl='.'\nwhile [ $# -gt 0 ]; do\nif [ \"$1\" = \"-pl\" ]; then pl=\"$2\"; shift 2; else shift; fi\ndone\nmkdir -p \"$pl/target\"\nprintf '/repo/a.jar:/repo/b.jar' > \"$pl/target/ide-compile-cp.txt\"\n",
+            "#!/bin/sh\nprintf '%s\\n' \"$@\" > args.txt\npl='.'\nwhile [ $# -gt 0 ]; do\nif [ \"$1\" = \"-pl\" ]; then pl=\"$2\"; shift 2; else shift; fi\ndone\nmkdir -p \"$pl/target\"\nprintf '/repo/a.jar:/repo/b.jar' > \"$pl/target/ide-compile-cp.txt\"\n",
         )
         .unwrap();
         fs::set_permissions(&script, fs::Permissions::from_mode(0o755)).unwrap();
@@ -327,5 +449,90 @@ mod tests {
         assert!(cp.contains("/repo/a.jar"), "{cp}");
         assert!(cp.contains("/repo/b.jar"), "{cp}");
         assert!(cp.split(separator).count() >= 3, "{cp}");
+        let args = fs::read_to_string(root.join("args.txt")).unwrap();
+        assert!(!args.lines().any(|a| a == "compile" || a == "package"), "{args}");
+    }
+
+    /// A launch uses runtime dependencies, while tests additionally see test-scope ones.
+    #[cfg(unix)]
+    #[test]
+    fn launch_module_classpath_uses_the_matching_dependency_scope() {
+        use std::os::unix::fs::PermissionsExt;
+
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        fixture(root);
+        let script = root.join("mvnw");
+        fs::write(
+            &script,
+            "#!/bin/sh\nprintf '%s\\n' \"$@\" > args.txt\npl='.'\nwhile [ $# -gt 0 ]; do\nif [ \"$1\" = \"-pl\" ]; then pl=\"$2\"; shift 2; else shift; fi\ndone\nmkdir -p \"$pl/target\"\nprintf '/repo/runtime.jar:/repo/test.jar' > \"$pl/target/ide-compile-cp.txt\"\n",
+        )
+        .unwrap();
+        fs::set_permissions(&script, fs::Permissions::from_mode(0o755)).unwrap();
+        let model = crate::load(root, &root.join("cache"), None);
+
+        let cache = root.join("cache");
+        let runtime =
+            module_classpath(root, &model, &root.join("app"), false, None, &cache, &CancellationToken::new()).unwrap();
+        assert!(runtime.contains("/repo/runtime.jar"), "{runtime}");
+        let args = fs::read_to_string(root.join("args.txt")).unwrap();
+        assert!(args.lines().any(|a| a == "compile"), "{args}");
+        assert!(!args.lines().any(|a| a == "package"), "{args}");
+        assert!(args.lines().any(|a| a == "-Dmdep.includeScope=runtime"), "{args}");
+
+        let test =
+            module_classpath(root, &model, &root.join("app"), true, None, &cache, &CancellationToken::new()).unwrap();
+        assert!(test.contains("/repo/test.jar"), "{test}");
+        let args = fs::read_to_string(root.join("args.txt")).unwrap();
+        assert!(args.lines().any(|a| a == "-Dmdep.includeScope=test"), "{args}");
+    }
+
+    /// The launch classpath follows the Maven runner JDK and is reused until that
+    /// build input changes; the probe does not run packaging plugins.
+    #[cfg(unix)]
+    #[test]
+    fn launch_classpath_cache_follows_the_runner_jdk() {
+        use std::os::unix::fs::PermissionsExt;
+
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        fixture(root);
+        let script = root.join("mvnw");
+        // `dependency:build-classpath` reports reactor outputs as absolute paths. Keep
+        // the fake probe faithful so the cache's existence check sees the output.
+        fs::write(
+            &script,
+            "#!/bin/sh\nprintf x >> calls.txt\npl='.'\nwhile [ $# -gt 0 ]; do\nif [ \"$1\" = \"-pl\" ]; then pl=\"$2\"; shift 2; else shift; fi\ndone\nmkdir -p \"$pl/target/classes\" \"$JAVA_HOME/classpath\"\n: > \"$JAVA_HOME/classpath/jdk.jar\"\nprintf '%s/classpath/jdk.jar:%s/%s/target/classes:%s/empty/target/classes' \"$JAVA_HOME\" \"$(pwd)\" \"$pl\" \"$(pwd)\" > \"$pl/target/ide-compile-cp.txt\"\n",
+        )
+        .unwrap();
+        fs::set_permissions(&script, fs::Permissions::from_mode(0o755)).unwrap();
+        let mut model = crate::load(root, &root.join("cache"), None);
+        for (name, version) in [("jdk21", "21"), ("jdk8", "8")] {
+            let home = root.join(name);
+            fs::create_dir_all(home.join("bin")).unwrap();
+            fs::write(home.join("release"), format!("JAVA_VERSION=\"{version}\"\n")).unwrap();
+            fs::write(home.join("bin/java"), "").unwrap();
+        }
+        let cache = root.join("classpath-cache");
+        let cancel = CancellationToken::new();
+        let jdk21 = root.join("jdk21");
+        for project in &mut model.maven.as_mut().unwrap().projects {
+            project.env.insert("JAVA_HOME".into(), jdk21.to_string_lossy().into_owned());
+        }
+        let first = module_classpath(root, &model, &root.join("app"), false, None, &cache, &cancel).unwrap();
+        assert!(first.contains("jdk21/classpath/jdk.jar"), "{first}");
+        assert!(!first.contains("jdk8/classpath/jdk.jar"), "{first}");
+        let second = module_classpath(root, &model, &root.join("app"), false, None, &cache, &cancel).unwrap();
+        assert_eq!(second, first);
+        assert_eq!(fs::read_to_string(root.join("calls.txt")).unwrap(), "x");
+
+        let jdk8 = root.join("jdk8");
+        for project in &mut model.maven.as_mut().unwrap().projects {
+            project.env.insert("JAVA_HOME".into(), jdk8.to_string_lossy().into_owned());
+        }
+        let switched = module_classpath(root, &model, &root.join("app"), false, None, &cache, &cancel).unwrap();
+        assert!(switched.contains("jdk8/classpath/jdk.jar"), "{switched}");
+        assert!(!switched.contains("jdk21/classpath/jdk.jar"), "{switched}");
+        assert_eq!(fs::read_to_string(root.join("calls.txt")).unwrap(), "xx");
     }
 }

crates/ide-build/src/maven.rs

@@ -712,18 +712,27 @@ pub(crate) fn launch_inputs(
         // 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("${") {
-                return None;
-            }
-            if !value.is_empty() {
-                out.push(dir.join(value));
+            // A source root under Maven's build directory is generated by the build itself.
+            // Skip it without resolving the property: `<build><directory>` may be custom, and
+            // hashing its rewritten files would make every launch look changed.
+            if !(input && el.text.contains("${project.build.directory}")) {
+                // Other properties can be overridden by -D, profiles or settings. Without
+                // Maven's effective model, leave them unresolved to conservatively disable reuse.
+                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() {
+                    let path = dir.join(value);
+                    // Conventional generated sources under target are also build outputs.
+                    if !(input && path.starts_with(dir.join("target"))) {
+                        out.push(path);
+                    }
+                }
             }
         }
         for child in &el.children {
@@ -2140,6 +2149,52 @@ mod tests {
         assert_eq!(known.goals, ["compile", "help", "testCompile"], "the common plugins keep their table");
     }
 
+    #[test]
+    fn launch_inputs_skip_generated_sources_under_the_project_build_directory() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(
+            root,
+            "pom.xml",
+            "<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version>\
+             <packaging>pom</packaging><modules><module>app</module></modules></project>",
+        );
+        write(
+            root,
+            "app/pom.xml",
+            r#"<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></parent>
+               <artifactId>app</artifactId><build><plugins><plugin>
+                 <groupId>org.codehaus.mojo</groupId><artifactId>build-helper-maven-plugin</artifactId>
+                 <executions><execution><configuration><sources>
+                   <source>${project.build.directory}/generated-sources/java</source>
+                 </sources></configuration></execution></executions>
+               </plugin></plugins></build></project>"#,
+        );
+        let model = load_with_repo(root, None);
+        let projects: Vec<&MavenProject> = model.projects.iter().collect();
+        let inputs = launch_inputs(root, &projects, None).expect("portable launch inputs");
+        assert!(!inputs.contains(&root.join("app/target/generated-sources/java")), "{inputs:?}");
+        assert!(inputs.contains(&root.join("app/src")), "conventional sources stay fingerprinted");
+    }
+
+    #[test]
+    fn launch_inputs_disable_reuse_for_file_activation_on_the_build_directory() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(
+            root,
+            "pom.xml",
+            r#"<project><groupId>demo</groupId><artifactId>app</artifactId><version>1</version>
+               <build><directory>${project.basedir}/custom-build</directory></build>
+               <profiles><profile><id>generated</id><activation><file>
+                 <exists>${project.build.directory}/enable-profile</exists>
+               </file></activation></profile></profiles></project>"#,
+        );
+        let model = load_with_repo(root, None);
+        let projects: Vec<&MavenProject> = model.projects.iter().collect();
+        assert!(launch_inputs(root, &projects, None).is_none());
+    }
+
     fn write(dir: &Path, rel: &str, text: &str) {
         let p = dir.join(rel);
         std::fs::create_dir_all(p.parent().unwrap()).unwrap();

crates/ide-build/src/maven/completion.rs

@@ -393,11 +393,13 @@ fn scan_versions(dir: &Path, typed: &str, budget: &mut u32) -> Vec<PomCompletion
     out
 }
 
-/// The repository directory of the `/`-separated `coordinates` (a group id, or
-/// a group and an artifact id), each segment validated against the layout's
-/// alphabet so POM text cannot walk outside `repo`.
+/// The repository directory of `coordinates` (a group id, or a group and an artifact
+/// id): the group's dots are directories, an artifact id is one directory whatever dots
+/// it has (`org/eclipse/platform/org.eclipse.core.runtime`). Each segment is validated
+/// against the layout's alphabet so POM text cannot walk outside `repo`.
 fn repo_dir(repo: &Path, coordinates: &[&str]) -> Option<PathBuf> {
-    let segments: Vec<&str> = coordinates.iter().flat_map(|c| c.split('.')).collect();
+    let (group, artifact) = coordinates.split_first()?;
+    let segments: Vec<&str> = group.split('.').chain(artifact.iter().copied()).collect();
     segments.iter().all(|s| segment(s)).then(|| segments.iter().fold(repo.to_path_buf(), |p, s| p.join(s)))
 }
 
@@ -460,6 +462,7 @@ mod tests {
             "org/example/lib/2.0-beta-1/lib-2.0-beta-1.jar",
             "org/example/lib/2.0/lib-2.0.pom",
             "net/nu/netty/4.1.100/netty-4.1.100.jar",
+            "org/eclipse/platform/org.eclipse.core.runtime/3.31.0/org.eclipse.core.runtime-3.31.0.jar",
             // Failed downloads (a version typed while editing): tracking files only, not installed.
             "org/example/lib/2/lib-2.jar.lastUpdated",
             "org/example/lib/3.0/lib-3.0.pom.lastUpdated",
@@ -570,9 +573,10 @@ mod tests {
         };
         // Only directories holding artifacts are group ids: `net` and `org`
         // alone never receive an install, their deeper levels do.
-        assert_eq!(options(""), ["net.nu", "org.apache.maven", "org.apache.maven.plugins", "org.example"]);
-        assert_eq!(options("org"), ["org.apache.maven", "org.apache.maven.plugins", "org.example"]);
-        assert_eq!(options("org."), ["org.apache.maven", "org.apache.maven.plugins", "org.example"]);
+        let org = ["org.apache.maven", "org.apache.maven.plugins", "org.eclipse.platform", "org.example"];
+        assert_eq!(options(""), [&["net.nu"][..], &org].concat());
+        assert_eq!(options("org"), org);
+        assert_eq!(options("org."), org);
         assert_eq!(options("org.spr"), Vec::<String>::new());
         assert_eq!(options("net."), ["net.nu"]);
     }
@@ -623,6 +627,19 @@ mod tests {
         };
         assert_eq!(options(""), ["2.0", "2.0-beta-1", "1.10", "1.9.1", "1.0"]);
         assert_eq!(options("1."), ["1.10", "1.9.1", "1.0"]);
+        // An artifact id with dots is one directory.
+        let dotted = local_options(
+            &repo,
+            &PomCompletionTarget {
+                from: 0,
+                to: 0,
+                typed: "".into(),
+                kind: PomCompletionKind::Version,
+                group: Some("org.eclipse.platform".into()),
+                artifact: Some("org.eclipse.core.runtime".into()),
+            },
+        );
+        assert_eq!(dotted.into_iter().map(|o| o.label).collect::<Vec<_>>(), ["3.31.0"]);
     }
 
     #[test]

crates/ide-build/src/sync.rs

@@ -270,6 +270,13 @@ fn run(
 
 /// The first error lines of a failed build, for the tool window.
 pub(crate) fn error_summary(text: &str) -> String {
+    // The JVM's "could not find or load main class" (localized) when `gradlew` has no jar.
+    if text.contains("org.gradle.wrapper.GradleWrapperMain") {
+        return "gradle/wrapper/gradle-wrapper.jar is missing (often excluded by a `*.jar` rule in .gitignore). \
+                Restore it, run `gradle wrapper` with an installed Gradle, or choose Distribution: Local installation \
+                in Settings › Build, Execution, Deployment › Gradle."
+            .to_owned();
+    }
     let lines: Vec<&str> = text
         .lines()
         .filter(|l| {
@@ -909,6 +916,8 @@ mod tests {
         let text = "[INFO] x\n[ERROR] Failed to execute goal\n[ERROR] \n[ERROR] Re-run Maven using -X\n";
         assert_eq!(error_summary(text), "Failed to execute goal");
         assert_eq!(error_summary("one\nlast line\n\n"), "last line");
+        let missing_jar = "错误: 找不到或无法加载主类 org.gradle.wrapper.GradleWrapperMain\n";
+        assert!(error_summary(missing_jar).starts_with("gradle/wrapper/gradle-wrapper.jar is missing"));
     }
 
     #[test]

crates/ide-core/src/editor_settings.rs

@@ -270,6 +270,8 @@ pub struct SmartKeysSettings {
     pub pair_quotes: bool,
     pub surround_selection: bool,
     pub tab_out_of_pair: bool,
+    /// Simultaneous `<tag></tag>` editing: renaming a tag renames its matching tag.
+    pub simultaneous_tag_editing: bool,
     /// Reformat on paste: `none` | `indentBlock` | `indentEachLine`.
     pub reformat_on_paste: String,
     pub escape_on_paste: bool,
@@ -289,6 +291,7 @@ impl Default for SmartKeysSettings {
             pair_quotes: true,
             surround_selection: true,
             tab_out_of_pair: true,
+            simultaneous_tag_editing: true,
             reformat_on_paste: "indentEachLine".into(),
             escape_on_paste: true,
             smart_indent: true,

crates/ide-core/src/event.rs

@@ -77,6 +77,9 @@ pub enum IdeEvent {
     WorkspaceEditApplied {
         id: u32,
         paths: Vec<crate::IpcPath>,
+        /// Made by an agent through the MCP server's tools: undoable like a refactoring, but
+        /// not announced as one.
+        by_agent: bool,
     },
     /// An open document's language changed (Settings › File Types, Override File
     /// Type), or its UI mode (a framework's root marker appeared or went).

crates/ide-core/src/remote_settings.rs

@@ -77,6 +77,8 @@ pub enum AutoUpload {
 #[serde(default, rename_all = "camelCase")]
 pub struct DeploymentSettings {
     pub servers: Vec<DeploymentServer>,
+    /// Server groups: Upload to… on a group uploads to each of its servers.
+    pub groups: Vec<DeploymentGroup>,
     /// Server used by Upload / Download / Sync and automatic upload; empty = none.
     pub default_server: String,
     pub auto_upload: AutoUpload,
@@ -92,6 +94,7 @@ impl Default for DeploymentSettings {
     fn default() -> Self {
         Self {
             servers: Vec::new(),
+            groups: Vec::new(),
             default_server: String::new(),
             auto_upload: AutoUpload::Never,
             delete_remote: false,
@@ -103,6 +106,16 @@ impl Default for DeploymentSettings {
     }
 }
 
+/// Named set of deployment servers that files are uploaded to together.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct DeploymentGroup {
+    pub id: String,
+    pub name: String,
+    /// [`DeploymentServer::id`]s, in upload order.
+    pub servers: Vec<String>,
+}
+
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 pub enum DeploymentType {

crates/ide-core/src/settings.rs

@@ -300,11 +300,30 @@ pub struct McpServerSettings {
     pub agent_tab_limit: u32,
     /// Archived agent tabs kept; older ones are closed.
     pub agent_archive_limit: u32,
+    /// Listen on [`Self::port`] in every run, rather than a free port each time, so HTTP clients and
+    /// port forwards keep working after a restart.
+    pub fixed_port: bool,
+    /// The port of [`Self::fixed_port`].
+    pub port: u16,
+    /// Keep the bearer token across runs (in the app data, readable by this user only) rather than
+    /// make a new one each run.
+    pub fixed_token: bool,
 }
 
+/// The default of [`McpServerSettings::port`].
+pub const DEFAULT_MCP_PORT: u16 = 26371;
+
 impl Default for McpServerSettings {
     fn default() -> Self {
-        Self { enabled: false, run_without_confirmation: false, agent_tab_limit: 1, agent_archive_limit: 999 }
+        Self {
+            enabled: false,
+            run_without_confirmation: false,
+            agent_tab_limit: 1,
+            agent_archive_limit: 999,
+            fixed_port: true,
+            port: DEFAULT_MCP_PORT,
+            fixed_token: false,
+        }
     }
 }
 
@@ -654,6 +673,28 @@ pub struct AppearanceSettings {
     pub status_bar_widgets: BTreeMap<String, bool>,
     /// Customize Main Toolbar; `None` = the default toolbar.
     pub main_toolbar: Option<MainToolbarSettings>,
+    /// Appearance › Background Image: an image shown through the IDE window.
+    pub background_image: BackgroundImageSettings,
+}
+
+/// Appearance › Background Image. An empty `path` shows no image.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct BackgroundImageSettings {
+    pub path: String,
+    /// Percent, 0–100.
+    pub opacity: u8,
+    /// `scale` (cover the window) | `plain` (original size) | `tile`.
+    pub fill: String,
+    /// Where the image is anchored: `center`, `top-left`, `top`, `top-right`, `left`, `right`,
+    /// `bottom-left`, `bottom`, `bottom-right`.
+    pub anchor: String,
+}
+
+impl Default for BackgroundImageSettings {
+    fn default() -> Self {
+        Self { path: String::new(), opacity: 15, fill: "scale".into(), anchor: "center".into() }
+    }
 }
 
 /// Main toolbar entries per side, in order: title widget ids (`project`,
@@ -724,6 +765,7 @@ impl Default for AppearanceSettings {
             navigation_bar: NavigationBarPosition::StatusBar,
             status_bar_widgets: BTreeMap::new(),
             main_toolbar: None,
+            background_image: BackgroundImageSettings::default(),
         }
     }
 }

crates/ide-dap/Cargo.toml

@@ -28,6 +28,9 @@ tracing.workspace = true
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"
 
+[target.'cfg(windows)'.dependencies]
+windows-sys = { version = "0.61", features = ["Wdk_System_Threading", "Win32_Foundation", "Win32_System_Diagnostics_ToolHelp", "Win32_System_Threading"] }
+
 [dev-dependencies]
 tracing-subscriber.workspace = true
 tokio = { workspace = true, features = ["net", "rt-multi-thread", "macros", "test-util"] }

crates/ide-dap/src/attach.rs

@@ -1,6 +1,7 @@
 //! Attach to Process: the current user's processes, grouped by the debugger that can
 //! attach to them (IDEA's `XAttachDebuggerProvider`s): JVMs with a JDWP agent, Node,
-//! Python (debugpy injection), Go binaries (Delve) and anything else natively (LLDB).
+//! Python (debugpy injection), .NET (netcoredbg), Go binaries (Delve) and anything else
+//! natively (LLDB).
 
 use crate::adapter;
 use ide_core::{IdeError, IdeResult};
@@ -14,6 +15,7 @@ pub enum AttachKind {
     Java,
     Node,
     Python,
+    Dotnet,
     Go,
     Native,
 }
@@ -95,13 +97,29 @@ fn file_name(path: &str) -> &str {
     path.rsplit(['/', '\\']).next().unwrap_or(path)
 }
 
+/// A .NET app: the `dotnet` host, or an apphost next to its `<name>.runtimeconfig.json`.
+pub fn is_dotnet(exe: &str) -> bool {
+    let path = Path::new(exe);
+    let Some(stem) = path.file_stem().and_then(|s| s.to_str()) else { return false };
+    if stem == "dotnet" {
+        return true;
+    }
+    path.is_absolute() && path.with_file_name(format!("{stem}.runtimeconfig.json")).is_file()
+}
+
 fn is_python(name: &str) -> bool {
     let n = name.strip_suffix(".exe").unwrap_or(name);
     n == "Python" || n.strip_prefix("python").is_some_and(|v| v.chars().all(|c| c.is_ascii_digit() || c == '.'))
 }
 
-/// Classifies a process; `is_go` is asked only for processes no interpreter claims.
-pub fn classify(p: &RawProcess, is_go: impl Fn(&str) -> bool, native_adapter: &str) -> Option<AttachableProcess> {
+/// Classifies a process; `is_dotnet` and `is_go` are asked only for processes no
+/// interpreter claims.
+pub fn classify(
+    p: &RawProcess,
+    is_dotnet: impl Fn(&str) -> bool,
+    is_go: impl Fn(&str) -> bool,
+    native_adapter: &str,
+) -> Option<AttachableProcess> {
     let name = file_name(&p.exe).to_owned();
     let make = |kind, adapter: &str, addr: Option<(Option<String>, u16)>| {
         let (host, port) = match addr {
@@ -129,6 +147,9 @@ pub fn classify(p: &RawProcess, is_go: impl Fn(&str) -> bool, native_adapter: &s
     if is_python(&name) {
         return make(AttachKind::Python, "debugpy", debugpy_listen(&p.args));
     }
+    if is_dotnet(&p.exe) {
+        return make(AttachKind::Dotnet, "netcoredbg", None);
+    }
     if is_go(&p.exe) {
         return make(AttachKind::Go, "delve", None);
     }
@@ -143,7 +164,7 @@ const GO_SCAN_LIMIT: u64 = 96 << 20;
 pub fn is_go_binary(exe: &str) -> bool {
     use std::io::Read;
     let skip = ["/System/", "/usr/", "/bin/", "/sbin/", "/Library/Apple/", "/Applications/"];
-    if skip.iter().any(|p| exe.starts_with(p)) || !Path::new(exe).is_absolute() {
+    if skip.iter().any(|p| exe.starts_with(p)) || is_windows_system(exe) || !Path::new(exe).is_absolute() {
         return false;
     }
     let Ok(file) = std::fs::File::open(exe) else { return false };
@@ -165,6 +186,17 @@ pub fn is_go_binary(exe: &str) -> bool {
     }
 }
 
+/// Windows' own and installed programs (`C:\Windows\…`, `C:\Program Files…`), like the
+/// system locations skipped on Unix.
+fn is_windows_system(exe: &str) -> bool {
+    let lower = exe.to_ascii_lowercase();
+    lower.get(1..).is_some_and(|rest| {
+        rest.starts_with(":\\windows\\")
+            || rest.starts_with(":\\program files\\")
+            || rest.starts_with(":\\program files (x86)\\")
+    })
+}
+
 /// The current user's processes (without this one).
 #[cfg(unix)]
 pub fn list_processes() -> IdeResult<Vec<RawProcess>> {
@@ -181,7 +213,7 @@ pub fn list_processes() -> IdeResult<Vec<RawProcess>> {
         let (pid, rest) = line.split_once(char::is_whitespace)?;
         Some((pid.parse().ok()?, rest.trim().to_owned()))
     };
-    // `comm` is the executable path on macOS; on Linux it is truncated, so read /proc.
+    // `comm` is the executable path as started on macOS; on Linux it is truncated, so read /proc.
     let exes: HashMap<u32, String> =
         if cfg!(target_os = "linux") { HashMap::new() } else { ps("pid=,comm=")?.lines().filter_map(split).collect() };
     let me = std::process::id();
@@ -190,9 +222,8 @@ pub fn list_processes() -> IdeResult<Vec<RawProcess>> {
         .filter_map(split)
         .filter(|(pid, _)| *pid != me)
         .map(|(pid, args)| {
-            let exe = exes
-                .get(&pid)
-                .cloned()
+            let exe = exe_path(pid)
+                .or_else(|| exes.get(&pid).cloned())
                 .or_else(|| std::fs::read_link(format!("/proc/{pid}/exe")).ok().map(|p| p.display().to_string()))
                 .unwrap_or_else(|| args.split_whitespace().next().unwrap_or_default().to_owned());
             RawProcess { pid, exe, args }
@@ -200,9 +231,134 @@ pub fn list_processes() -> IdeResult<Vec<RawProcess>> {
         .collect())
 }
 
-#[cfg(not(unix))]
+/// The processes this user may open (without this one): system and other users'
+/// processes refuse `PROCESS_QUERY_LIMITED_INFORMATION` and are left out.
+#[cfg(windows)]
 pub fn list_processes() -> IdeResult<Vec<RawProcess>> {
-    Err(IdeError::unavailable("Attach to Process is not supported on this platform yet"))
+    windows_processes::list()
+}
+
+#[cfg(windows)]
+mod windows_processes {
+    use super::RawProcess;
+    use ide_core::{IdeError, IdeResult};
+    use std::os::windows::io::{AsRawHandle, FromRawHandle, OwnedHandle};
+    use windows_sys::Wdk::System::Threading::{NtQueryInformationProcess, ProcessCommandLineInformation};
+    use windows_sys::Win32::Foundation::{INVALID_HANDLE_VALUE, UNICODE_STRING};
+    use windows_sys::Win32::System::Diagnostics::ToolHelp::{
+        CreateToolhelp32Snapshot, PROCESSENTRY32W, Process32FirstW, Process32NextW, TH32CS_SNAPPROCESS,
+    };
+    use windows_sys::Win32::System::Threading::{
+        OpenProcess, PROCESS_NAME_WIN32, PROCESS_QUERY_LIMITED_INFORMATION, QueryFullProcessImageNameW,
+    };
+
+    pub fn list() -> IdeResult<Vec<RawProcess>> {
+        let me = std::process::id();
+        Ok(pids()?
+            .into_iter()
+            .filter(|&pid| pid != 0 && pid != me)
+            .filter_map(|pid| {
+                // SAFETY: plain call; a non-null result is a process handle owned here.
+                let handle = unsafe { OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, 0, pid) };
+                if handle.is_null() {
+                    return None;
+                }
+                // SAFETY: as above.
+                let process = unsafe { OwnedHandle::from_raw_handle(handle) };
+                let exe = image_path(&process)?;
+                let args = command_line(&process).unwrap_or_else(|| exe.clone());
+                Some(RawProcess { pid, exe, args })
+            })
+            .collect())
+    }
+
+    fn pids() -> IdeResult<Vec<u32>> {
+        let mut out = Vec::new();
+        // SAFETY: a snapshot handle owned here and an entry sized as the API requires.
+        unsafe {
+            let snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
+            if snapshot.is_null() || snapshot == INVALID_HANDLE_VALUE {
+                return Err(IdeError::unavailable(format!(
+                    "cannot list processes: {}",
+                    std::io::Error::last_os_error()
+                )));
+            }
+            let snapshot = OwnedHandle::from_raw_handle(snapshot);
+            let mut entry = PROCESSENTRY32W { dwSize: size_of::<PROCESSENTRY32W>() as u32, ..Default::default() };
+            let mut more = Process32FirstW(snapshot.as_raw_handle(), &mut entry);
+            while more != 0 {
+                out.push(entry.th32ProcessID);
+                more = Process32NextW(snapshot.as_raw_handle(), &mut entry);
+            }
+        }
+        Ok(out)
+    }
+
+    fn image_path(process: &OwnedHandle) -> Option<String> {
+        let mut buf = vec![0u16; 32 * 1024];
+        let mut len = buf.len() as u32;
+        // SAFETY: a live process handle with query access; `len` is the buffer's capacity.
+        let ok = unsafe {
+            QueryFullProcessImageNameW(process.as_raw_handle(), PROCESS_NAME_WIN32, buf.as_mut_ptr(), &mut len)
+        };
+        (ok != 0).then(|| String::from_utf16_lossy(&buf[..len as usize]))
+    }
+
+    /// The command line (Windows 8.1+), read with the same limited query access.
+    fn command_line(process: &OwnedHandle) -> Option<String> {
+        let mut size = 0u32;
+        // SAFETY: a size query with no buffer; it fails and reports the size it needs.
+        unsafe {
+            NtQueryInformationProcess(
+                process.as_raw_handle(),
+                ProcessCommandLineInformation,
+                std::ptr::null_mut(),
+                0,
+                &mut size,
+            )
+        };
+        if (size as usize) < size_of::<UNICODE_STRING>() {
+            return None;
+        }
+        // u64 elements keep the UNICODE_STRING header aligned.
+        let mut buf = vec![0u64; (size as usize).div_ceil(8)];
+        // SAFETY: a buffer of at least `size` bytes.
+        let status = unsafe {
+            NtQueryInformationProcess(
+                process.as_raw_handle(),
+                ProcessCommandLineInformation,
+                buf.as_mut_ptr().cast(),
+                size,
+                &mut size,
+            )
+        };
+        if status < 0 {
+            return None;
+        }
+        // SAFETY: on success the buffer starts with a UNICODE_STRING whose text lies inside it.
+        let text = unsafe {
+            let s = &*buf.as_ptr().cast::<UNICODE_STRING>();
+            if s.Buffer.is_null() {
+                return None;
+            }
+            std::slice::from_raw_parts(s.Buffer, usize::from(s.Length) / 2)
+        };
+        Some(String::from_utf16_lossy(text))
+    }
+}
+
+/// The full executable path: `comm` keeps a relative path a process was started with.
+#[cfg(target_os = "macos")]
+fn exe_path(pid: u32) -> Option<String> {
+    let mut buf = vec![0u8; libc::PROC_PIDPATHINFO_MAXSIZE as usize];
+    // SAFETY: the buffer holds `PROC_PIDPATHINFO_MAXSIZE` bytes, as the call requires.
+    let n = unsafe { libc::proc_pidpath(i32::try_from(pid).ok()?, buf.as_mut_ptr().cast(), buf.len() as u32) };
+    (n > 0).then(|| String::from_utf8_lossy(&buf[..n as usize]).into_owned())
+}
+
+#[cfg(all(unix, not(target_os = "macos")))]
+fn exe_path(_pid: u32) -> Option<String> {
+    None
 }
 
 /// Node's default inspector port, which `SIGUSR1` opens.
@@ -244,7 +400,7 @@ pub fn attachable_processes() -> IdeResult<Vec<AttachableProcess>> {
     let cwd = std::env::temp_dir();
     let native = if adapter::resolve_binary("codelldb", &cwd).is_some() { "codelldb" } else { "lldb-dap" };
     let mut out: Vec<AttachableProcess> =
-        list_processes()?.iter().filter_map(|p| classify(p, is_go_binary, native)).collect();
+        list_processes()?.iter().filter_map(|p| classify(p, is_dotnet, is_go_binary, native)).collect();
     out.sort_by(|a, b| a.kind.cmp(&b.kind).then_with(|| a.name.to_lowercase().cmp(&b.name.to_lowercase())));
     Ok(out)
 }
@@ -258,7 +414,8 @@ mod tests {
     }
 
     fn kind(exe: &str, args: &str) -> Option<(AttachKind, Option<u16>)> {
-        classify(&raw(exe, args), |e| e.ends_with("/gosrv"), "codelldb").map(|p| (p.kind, p.port))
+        classify(&raw(exe, args), |e| e.ends_with("/Api"), |e| e.ends_with("/gosrv"), "codelldb")
+            .map(|p| (p.kind, p.port))
     }
 
     #[test]
@@ -292,11 +449,37 @@ mod tests {
             kind("/Library/Frameworks/Python.framework/Versions/3.12/Resources/Python.app/Contents/MacOS/Python", "x"),
             Some((AttachKind::Python, None))
         );
+        assert_eq!(kind("/home/me/Api", "./Api"), Some((AttachKind::Dotnet, None)));
         assert_eq!(kind("/home/me/gosrv", "./gosrv"), Some((AttachKind::Go, None)));
         assert_eq!(kind("/home/me/a.out", "./a.out"), Some((AttachKind::Native, None)));
         assert!(!is_python("pythonista"));
     }
 
+    #[test]
+    fn detects_dotnet_hosts_and_apphosts() {
+        let dir = std::env::temp_dir().join(format!("openidea-attach-dotnet-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let app = dir.join("Api");
+        std::fs::write(&app, b"").unwrap();
+        std::fs::write(dir.join("Api.runtimeconfig.json"), b"{}").unwrap();
+        let tool = dir.join("tool");
+        std::fs::write(&tool, b"").unwrap();
+        assert!(is_dotnet(app.to_str().unwrap()));
+        assert!(!is_dotnet(tool.to_str().unwrap()));
+        assert!(is_dotnet("/usr/local/share/dotnet/dotnet"));
+        assert!(is_dotnet("dotnet"));
+        assert!(!is_dotnet("Api"));
+        std::fs::remove_dir_all(&dir).unwrap();
+    }
+
+    #[test]
+    fn skips_windows_system_programs() {
+        assert!(is_windows_system(r"C:\Windows\System32\svchost.exe"));
+        assert!(is_windows_system(r"c:\program files (x86)\App\app.exe"));
+        assert!(!is_windows_system(r"D:\src\srv\srv.exe"));
+        assert!(!is_windows_system("/usr/bin/true"));
+    }
+
     #[test]
     fn detects_go_binaries_by_buildinfo() {
         let dir = std::env::temp_dir().join(format!("openidea-attach-{}", std::process::id()));

crates/ide-dap/tests/real_adapters.rs

@@ -557,6 +557,17 @@ async fn attach_to_processes() {
             extra: |pid, _| serde_json::json!({"pid": pid}),
         },
     ];
+    // A .NET app built into `dotnet/bin` (`<OutDir>bin</OutDir>`), attached by its apphost.
+    let dotnet_app = dir.join("dotnet/bin").join(if cfg!(windows) { "Server.exe" } else { "Server" });
+    if dotnet_app.is_file() {
+        cases.push(AttachCase {
+            kind: attach::AttachKind::Dotnet,
+            command: vec![s(&dotnet_app)],
+            source: dir.join("dotnet/Program.cs"),
+            line: 1,
+            extra: |pid, _| serde_json::json!({"processId": pid, "justMyCode": true}),
+        });
+    }
     if java_server.is_some() {
         cases.insert(
             0,

crates/ide-db/src/conn.rs

@@ -753,7 +753,7 @@ impl Pool {
             return crate::oracle::OraclePool::connect(source, password, &setup).await.map(Pool::Oracle);
         }
         if source.driver == DbDriver::Snowflake {
-            return crate::snowflake::SnowflakePool::connect(source, password, setup).await.map(Pool::Snowflake);
+            return crate::snowflake::SnowflakePool::connect(source, password, setup, root).await.map(Pool::Snowflake);
         }
         let timeout = setup.connect_timeout.unwrap_or(Duration::from_secs(30));
         let init = Arc::new(setup.statements);

crates/ide-db/src/lib.rs

@@ -1491,18 +1491,21 @@ impl DbManager {
         let Some(session) = session else { return Ok(()) };
         let mut held = session.lock().await;
         let Some(mut conn) = held.take() else { return Ok(()) };
-        let result = async {
-            conn.command(if commit { "COMMIT" } else { "ROLLBACK" }).await?;
-            conn.restore_default().await
-        }
-        .await;
-        match result {
-            Ok(()) => Ok(()),
-            Err(e) => {
+        if let Err(e) = conn.command(if commit { "COMMIT" } else { "ROLLBACK" }).await {
+            // Discarding a Snowflake connection doesn't end its session, which the data source's
+            // other targets share: the transaction stays open, so it stays held to be ended again.
+            if matches!(conn, conn::Held::Snowflake(..)) {
+                *held = Some(conn);
+            } else {
                 conn.discard().await;
-                Err(e)
             }
+            return Err(e);
         }
+        if let Err(e) = conn.restore_default().await {
+            conn.discard().await;
+            return Err(e);
+        }
+        Ok(())
     }
 
     #[allow(clippy::too_many_arguments)]

crates/ide-db/src/snowflake/mod.rs

@@ -78,7 +78,8 @@ pub(crate) fn sso_seed(key: &str, token: &str) {
     }
 }
 
-/// Live sessions by their connection settings, so targets opened with the same settings share one.
+/// Live sessions by data source and connection settings, so the targets of one data source (its
+/// databases, the tree, consoles) opened with the same settings share one.
 static SESSIONS: LazyLock<parking_lot::Mutex<HashMap<String, Weak<State>>>> =
     LazyLock::new(|| parking_lot::Mutex::new(HashMap::new()));
 
@@ -106,6 +107,15 @@ struct Lane {
     context: parking_lot::Mutex<Option<String>>,
 }
 
+/// What [`SnowflakePool::statement`] does when the session is gone and it signs in again.
+#[derive(Clone, Copy)]
+enum Lost<'a> {
+    /// Runs the statement again on the new session, after this `USE` when there is one.
+    Enter(Option<&'a str>),
+    /// Fails: the statement was part of a transaction that ended with the session.
+    Fail,
+}
+
 const CONSOLE: usize = 0;
 const METADATA: usize = 1;
 
@@ -251,7 +261,12 @@ fn gunzip(bytes: Vec<u8>) -> IdeResult<Vec<u8>> {
 }
 
 impl SnowflakePool {
-    pub(crate) async fn connect(source: &DataSource, secret: Option<&str>, setup: Setup) -> IdeResult<Self> {
+    pub(crate) async fn connect(
+        source: &DataSource,
+        secret: Option<&str>,
+        setup: Setup,
+        root: Option<&std::path::Path>,
+    ) -> IdeResult<Self> {
         let settings = source.snowflake();
         let endpoint = account::endpoint(source)?;
         let user = source.user.trim();
@@ -302,9 +317,15 @@ impl SnowflakePool {
             lane: CONSOLE,
         };
         // Everything that makes a session what it is, the secret included (hashed: the key is only compared).
+        // The data source and its project too: its databases share a session, but another data source
+        // with the same settings, or the same one in another project (a plugin's source has the same id
+        // in every project), gets its own: its statements and transactions are not this one's. A browser
+        // sign-in is still shared through the cached ID token.
         let key = blake3::hash(
             format!(
-                "{}\0{user}\0{:?}\0{}\0{}\0{}\0{}\0{:?}\0{:?}",
+                "{:?}\0{}\0{}\0{user}\0{:?}\0{}\0{}\0{}\0{}\0{:?}\0{:?}",
+                root,
+                source.id,
                 api.address(),
                 settings.auth,
                 secret.unwrap_or_default(),
@@ -636,13 +657,18 @@ impl SnowflakePool {
             () = self.closed.cancelled() => return Err(closed()),
             turn = self.lane().turn.lock() => turn,
         };
-        // A `USE` needs no schema to run in, and may be what makes the schema reachable.
-        if first_word(sql) != "USE" {
-            self.enter(schema, cancel).await?;
-        }
+        // A `USE` needs no schema to run in, and may be what makes the schema reachable. Ending a
+        // transaction needs none either, and must not fail because the schema is gone meanwhile.
+        let context = match first_word(sql).as_str() {
+            "USE" | "COMMIT" | "ROLLBACK" => None,
+            _ => {
+                self.enter(schema, cancel).await?;
+                self.context(schema)
+            }
+        };
         // These can move the session to another database or schema.
         let moves = matches!(first_word(sql).as_str(), "USE" | "CALL" | "EXECUTE");
-        let result = self.statement(sql, skip, max_rows, cancel).await;
+        let result = self.statement(sql, skip, max_rows, Lost::Enter(context.as_deref()), cancel).await;
         if moves {
             *self.lane().context.lock() = None;
         }
@@ -655,16 +681,14 @@ impl SnowflakePool {
             && self.lane().context.lock().as_deref() != Some(wanted.as_str())
         {
             *self.lane().context.lock() = None;
-            match self.statement(&wanted, 0, 0, cancel).await {
-                Ok(_) => {}
-                // The session's role may not use this database or schema (after `USE ROLE`, or a
-                // schema that is gone). The statement still runs, in the session's own context:
-                // it may be the `USE` that leads back, or name its objects in full. Asked again
-                // once a statement moves the session.
-                Err(refused) if refused.kind == ErrorKind::InvalidInput => {
-                    tracing::warn!("Snowflake: the session did not enter its database and schema");
-                }
-                Err(error) => return Err(error),
+            // Refused (the session's role may not use this database or schema): the statement
+            // does not run, since the session is still wherever it was, which may be another
+            // target's database. Tried again with the next statement.
+            if let Err(error) = self.statement(&wanted, 0, 0, Lost::Enter(None), cancel).await {
+                return Err(IdeError {
+                    message: format!("{wanted} failed, so the statement was not run: {}", error.message),
+                    ..error
+                });
             }
             *self.lane().context.lock() = Some(wanted);
         }
@@ -680,11 +704,11 @@ impl SnowflakePool {
         let _turn = self.lane().turn.lock().await;
         let cancel = CancellationToken::new();
         self.enter(None, &cancel).await?;
-        self.statement("BEGIN", 0, 0, &cancel).await?;
+        self.statement("BEGIN", 0, 0, Lost::Enter(self.context(None).as_deref()), &cancel).await?;
         let changes = async {
             let mut total = 0;
             for (sql, expect_one) in statements {
-                let changed = self.statement(sql, 0, 0, &cancel).await?.affected.unwrap_or(0.0) as u64;
+                let changed = self.statement(sql, 0, 0, Lost::Fail, &cancel).await?.affected.unwrap_or(0.0) as u64;
                 if *expect_one && changed != 1 {
                     return Err(IdeError::invalid(format!(
                         "{sql}: expected to change 1 row, changed {changed}; nothing was saved"
@@ -697,22 +721,24 @@ impl SnowflakePool {
         .await;
         match changes {
             Ok(total) => {
-                self.statement("COMMIT", 0, 0, &cancel).await?;
+                self.statement("COMMIT", 0, 0, Lost::Fail, &cancel).await?;
                 Ok(total)
             }
             Err(error) => {
-                let _ = self.statement("ROLLBACK", 0, 0, &cancel).await;
+                let _ = self.statement("ROLLBACK", 0, 0, Lost::Fail, &cancel).await;
                 Err(error)
             }
         }
     }
 
-    /// One statement on the session; the caller holds the session's turn.
+    /// One statement on the session; the caller holds the session's turn. `lost`: what to do when
+    /// the session is gone and a new one is signed in to.
     async fn statement(
         &self,
         sql: &str,
         skip: usize,
         max_rows: usize,
+        lost: Lost<'_>,
         cancel: &CancellationToken,
     ) -> IdeResult<QueryResult> {
         let started = Instant::now();
@@ -743,7 +769,24 @@ impl SnowflakePool {
                 Ok(Outcome::Done(result)) => return Ok(*result),
                 Ok(Outcome::Expired { gone }) if !renewed => {
                     renewed = true;
-                    tokens = if gone { self.login().await? } else { self.renew(&tokens).await? };
+                    if !gone {
+                        tokens = self.renew(&tokens).await?;
+                        continue;
+                    }
+                    if let Lost::Fail = lost {
+                        // The transaction ended with the session: nothing of it was saved.
+                        let _ = self.login().await;
+                        return Err(IdeError::new(
+                            ErrorKind::Io,
+                            "Snowflake: the session was lost during the transaction; nothing was saved",
+                        ));
+                    }
+                    // The new session is under the login's database and schema, which may be another
+                    // target's: back to this one's before the statement runs again.
+                    tokens = self.login().await?;
+                    if let Lost::Enter(Some(wanted)) = lost {
+                        self.reenter(wanted, &tokens, cancel).await?;
+                    }
                 }
                 Ok(Outcome::Expired { .. }) => {
                     return Err(IdeError::new(ErrorKind::Io, "Snowflake: the session expired; reconnect"));
@@ -753,6 +796,33 @@ impl SnowflakePool {
         }
     }
 
+    /// [`enter`](Self::enter) on a session just signed in to (its `tokens`), within [`statement`](Self::statement).
+    async fn reenter(&self, wanted: &str, tokens: &Tokens, cancel: &CancellationToken) -> IdeResult<()> {
+        let request_id = uuid();
+        let outcome = tokio::select! {
+            biased;
+            () = cancel.cancelled() => return Err(IdeError::cancelled()),
+            () = self.closed.cancelled() => return Err(closed()),
+            outcome = self.run(wanted, 0, 0, tokens, &request_id, Instant::now()) => outcome,
+        };
+        match outcome {
+            Ok(Outcome::Done(_)) => {
+                *self.lane().context.lock() = Some(wanted.to_owned());
+                Ok(())
+            }
+            Ok(Outcome::Expired { .. }) => {
+                Err(IdeError::new(ErrorKind::Io, "Snowflake: the session expired; reconnect"))
+            }
+            Err(error) => {
+                let error = self.shared.api.scrub.clean(error);
+                Err(IdeError {
+                    message: format!("{wanted} failed, so the statement was not run: {}", error.message),
+                    ..error
+                })
+            }
+        }
+    }
+
     async fn run(
         &self,
         sql: &str,

crates/ide-db/src/snowflake/tests.rs

@@ -407,13 +407,64 @@ async fn a_lost_session_signs_in_again() {
     let (listener, port) = bind().await;
     let gone = r#"{"success":false,"code":"390114","message":"Authentication token has expired. The user must authenticate again."}"#;
     let again = r#"{"success":true,"data":{"token":"session-token-3","masterToken":"master-token-3"}}"#;
-    let server = serve(listener, vec![ok(LOGIN_OK), ok(gone), ok(again), ok(one()), ok(CLOSED_OK)]);
+    let status = json!({ "success": true, "data": { "rowtype": [{ "name": "status", "type": "text" }],
+        "rowset": [["Statement executed successfully."]], "queryResultFormat": "json", "statementTypeId": 0x5000 } })
+    .to_string();
+    let server = serve(listener, vec![ok(LOGIN_OK), ok(gone), ok(again), ok(status), ok(one()), ok(CLOSED_OK)]);
     let pool = Pool::connect(&source(port), None, None).await.unwrap();
     pool.execute("select 1", 5, &CancellationToken::new()).await.unwrap();
     pool.close().await;
     let seen = server.await.unwrap();
     assert!(seen[2].line().starts_with("POST /session/v1/login-request?"), "{}", seen[2].line());
-    assert_eq!(seen[3].header("authorization"), Some("Snowflake Token=\"session-token-3\""));
+    // The new session enters the target's schema before the statement runs again.
+    assert_eq!(seen[3].json()["sqlText"], "USE SCHEMA \"ANALYTICS\".\"PUBLIC\"");
+    assert_eq!(seen[4].json()["sqlText"], "select 1");
+    assert_eq!(seen[4].header("authorization"), Some("Snowflake Token=\"session-token-3\""));
+}
+
+#[tokio::test]
+async fn a_lost_session_runs_the_statement_in_its_own_database_again() {
+    let (listener, port) = bind().await;
+    let gone = r#"{"success":false,"code":"390114","message":"Authentication token has expired. The user must authenticate again."}"#;
+    let again = r#"{"success":true,"data":{"token":"session-token-3","masterToken":"master-token-3"}}"#;
+    let status = || {
+        json!({ "success": true, "data": { "rowtype": [{ "name": "status", "type": "text" }],
+            "rowset": [["Statement executed successfully."]], "queryResultFormat": "json", "statementTypeId": 0x5000 } })
+        .to_string()
+    };
+    // Raw Data entered, the statement finds the session gone, a new login (under ANALYTICS),
+    // Raw Data entered again, the statement.
+    let replies = vec![ok(LOGIN_OK), ok(status()), ok(gone), ok(again), ok(status()), ok(one()), ok(CLOSED_OK)];
+    let server = serve(listener, replies);
+    let first = Pool::connect(&source(port), None, None).await.unwrap();
+    let mut other = source(port);
+    other.database = "Raw Data".into();
+    other.options.default_schema = String::new();
+    let second = Pool::connect(&other, None, None).await.unwrap();
+    second.execute("delete from t", 1, &CancellationToken::new()).await.unwrap();
+    first.close().await;
+    second.close().await;
+    let sent: Vec<String> =
+        server.await.unwrap()[1..6].iter().map(|r| r.json()["sqlText"].as_str().unwrap_or("").to_owned()).collect();
+    let raw = "USE DATABASE \"Raw Data\"";
+    assert_eq!(sent, [raw, "delete from t", "", raw, "delete from t"]);
+}
+
+#[tokio::test]
+async fn a_transaction_ends_even_when_its_schema_is_gone() {
+    let (listener, port) = bind().await;
+    let status = json!({ "success": true, "data": { "rowtype": [{ "name": "status", "type": "text" }],
+        "rowset": [["Statement executed successfully."]], "queryResultFormat": "json", "statementTypeId": 0x5000 } })
+    .to_string();
+    let server = serve(listener, vec![ok(LOGIN_OK), ok(status), ok(CLOSED_OK)]);
+    let pool = Pool::connect(&source(port), None, None).await.unwrap();
+    // The console's schema was dropped since it was picked: ending the transaction doesn't switch to it.
+    let mut console = crate::conn::Held::acquire(&pool).await.unwrap();
+    console.apply_context(Some("Dropped")).await.unwrap();
+    console.execute(&pool, "ROLLBACK", 0, &CancellationToken::new()).await.unwrap();
+    pool.close().await;
+    let seen = server.await.unwrap();
+    assert_eq!(seen[1].json()["sqlText"], "ROLLBACK");
 }
 
 #[tokio::test]
@@ -714,7 +765,7 @@ async fn a_console_schema_is_switched_with_its_statement_and_only_when_needed()
 }
 
 #[tokio::test]
-async fn a_role_that_may_not_use_the_schema_still_runs_statements() {
+async fn a_role_that_may_not_use_the_schema_runs_nothing_elsewhere() {
     let status = || {
         json!({ "success": true, "data": { "rowtype": [{ "name": "status", "type": "text" }],
             "rowset": [["Statement executed successfully."]], "queryResultFormat": "json", "statementTypeId": 0x5000 } })
@@ -722,14 +773,12 @@ async fn a_role_that_may_not_use_the_schema_still_runs_statements() {
     };
     let refused = r#"{"success":false,"code":"002043","message":"SQL compilation error:\nObject does not exist, or operation cannot be performed."}"#;
     let (listener, port) = bind().await;
-    // use role | the schema is refused once, the statement runs | the next one does not ask again |
-    // a role that is not granted | use role back, the schema is entered again
+    // use role | the schema is refused, the statement is not sent | asked again, refused again |
+    // use role back, the schema is entered, the statement runs
     let replies = vec![
         ok(LOGIN_OK),
         ok(status()),
         ok(refused),
-        ok(one()),
-        ok(one()),
         ok(refused),
         ok(status()),
         ok(status()),
@@ -740,20 +789,22 @@ async fn a_role_that_may_not_use_the_schema_still_runs_statements() {
     let pool = Pool::connect(&source(port), None, None).await.unwrap();
     let cancel = CancellationToken::new();
     pool.execute("use role auditor", 0, &cancel).await.unwrap();
-    pool.execute("select 1", 1, &cancel).await.unwrap();
-    pool.execute("select 2", 1, &cancel).await.unwrap();
-    let missing = pool.execute("use role nobody", 0, &cancel).await.unwrap_err();
-    assert!(missing.message.contains("002043") && missing.message.contains("granted"), "{}", missing.message);
+    let error = pool.execute("delete from t", 1, &cancel).await.unwrap_err();
+    assert!(
+        error.message.contains("USE SCHEMA")
+            && error.message.contains("was not run")
+            && error.message.contains("002043"),
+        "{}",
+        error.message
+    );
+    assert!(pool.execute("select 2", 1, &cancel).await.is_err());
     pool.execute("use role analyst", 0, &cancel).await.unwrap();
     pool.execute("select 3", 1, &cancel).await.unwrap();
     pool.close().await;
     let sent: Vec<String> =
-        server.await.unwrap()[1..9].iter().map(|r| r.json()["sqlText"].as_str().unwrap().to_owned()).collect();
+        server.await.unwrap()[1..7].iter().map(|r| r.json()["sqlText"].as_str().unwrap().to_owned()).collect();
     let schema = "USE SCHEMA \"ANALYTICS\".\"PUBLIC\"";
-    assert_eq!(
-        sent,
-        ["use role auditor", schema, "select 1", "select 2", "use role nobody", "use role analyst", schema, "select 3"]
-    );
+    assert_eq!(sent, ["use role auditor", schema, schema, "use role analyst", schema, "select 3"]);
 }
 
 #[tokio::test]
@@ -785,6 +836,45 @@ async fn databases_of_one_data_source_share_a_login() {
     assert!(seen[4].line().starts_with("POST /session?delete=true"), "{}", seen[4].line());
 }
 
+#[tokio::test]
+async fn data_sources_with_the_same_settings_have_their_own_sessions() {
+    let (listener, port) = bind().await;
+    let second = r#"{"success":true,"data":{"token":"session-token-2","masterToken":"master-token-2"}}"#;
+    let server = serve(listener, vec![ok(LOGIN_OK), ok(second), ok(one()), ok(one()), ok(CLOSED_OK), ok(CLOSED_OK)]);
+    let first = Pool::connect(&source(port), None, None).await.unwrap();
+    let mut copy = source(port);
+    copy.id = format!("{}-copy", copy.id);
+    let other = Pool::connect(&copy, None, None).await.unwrap();
+    let cancel = CancellationToken::new();
+    first.execute("select 1", 1, &cancel).await.unwrap();
+    other.execute("select 2", 1, &cancel).await.unwrap();
+    first.close().await;
+    other.close().await;
+    let seen = server.await.unwrap();
+    assert!(seen[1].line().starts_with("POST /session/v1/login-request?"), "{}", seen[1].line());
+    assert_eq!(seen[2].header("authorization"), Some("Snowflake Token=\"session-token-1\""));
+    assert_eq!(seen[3].header("authorization"), Some("Snowflake Token=\"session-token-2\""));
+}
+
+#[tokio::test]
+async fn one_data_source_in_two_projects_has_a_session_in_each() {
+    let (listener, port) = bind().await;
+    let second = r#"{"success":true,"data":{"token":"session-token-2","masterToken":"master-token-2"}}"#;
+    let server = serve(listener, vec![ok(LOGIN_OK), ok(second), ok(one()), ok(one()), ok(CLOSED_OK), ok(CLOSED_OK)]);
+    // A plugin's data source has the same id in every project.
+    let first = Pool::connect(&source(port), None, Some(std::path::Path::new("/projects/a"))).await.unwrap();
+    let other = Pool::connect(&source(port), None, Some(std::path::Path::new("/projects/b"))).await.unwrap();
+    let cancel = CancellationToken::new();
+    first.execute("select 1", 1, &cancel).await.unwrap();
+    other.execute("select 2", 1, &cancel).await.unwrap();
+    first.close().await;
+    other.close().await;
+    let seen = server.await.unwrap();
+    assert!(seen[1].line().starts_with("POST /session/v1/login-request?"), "{}", seen[1].line());
+    assert_eq!(seen[2].header("authorization"), Some("Snowflake Token=\"session-token-1\""));
+    assert_eq!(seen[3].header("authorization"), Some("Snowflake Token=\"session-token-2\""));
+}
+
 #[tokio::test]
 async fn metadata_runs_on_its_own_session_beside_a_busy_console() {
     let (listener, port) = bind().await;

crates/ide-extension/src/manifest.rs

@@ -34,7 +34,7 @@ use std::path::{Component, Path, PathBuf};
 
 pub const MANIFEST_FILE: &str = "plugin.toml";
 /// The plugin API (engine) version this host implements.
-pub const ENGINE_VERSION: &str = "1.7.0";
+pub const ENGINE_VERSION: &str = "1.8.0";
 /// The 0.1 API, still accepted for contribution-only packages and 0.1 components.
 pub const LEGACY_API: &str = "0.1";
 /// Marketplace categories, in the order they are shown.
@@ -166,6 +166,7 @@ pub const EVENT_KINDS: &[&str] = &[
     "editor-focused",
     "action-performed",
     "vcs-changed",
+    "problems-changed",
 ];
 
 impl std::fmt::Display for ActivationEvent {
@@ -372,6 +373,11 @@ impl Manifest {
             {
                 self.needs_api(&format!("`{event}`"), 6)?;
             }
+            // Added after 1.7.0 shipped: a 1.7 host rejects the manifest, so the gate is the minor
+            // that carries it.
+            if matches!(event, ActivationEvent::Event(kind) if kind == "problems-changed") {
+                self.needs_api(&format!("`{event}`"), 8)?;
+            }
             if matches!(event, ActivationEvent::Event(kind) if matches!(kind.as_str(), "file-closed" | "settings-changed" | "input-mode-changed" | "run-exited" | "terminal-exited" | "content-tab-action"))
             {
                 self.needs_api(&format!("`{event}`"), 4)?;

crates/ide-host/src/diagnostics_store.rs

@@ -0,0 +1,78 @@
+//! Host-owned diagnostics snapshot: every `Diagnostics` event lands here, whoever
+//! emitted it and whatever window it was addressed to. Plugins read this instead of
+//! the UI-reported Problems reports, so what a plugin sees no longer depends on
+//! window lifetime, the invoking window's project, or the report loop's liveness.
+
+use ide_core::{Diagnostic, EventSink, IdeEvent, SharedSink};
+use parking_lot::RwLock;
+use std::collections::BTreeMap;
+use std::path::PathBuf;
+use std::sync::Arc;
+
+#[derive(Default)]
+pub struct DiagnosticsStore(RwLock<BTreeMap<PathBuf, BTreeMap<String, Vec<Diagnostic>>>>);
+
+impl DiagnosticsStore {
+    /// Full replacement for one (file, producer), like the event itself.
+    pub fn replace(&self, path: &PathBuf, source: &str, items: Vec<Diagnostic>) {
+        let mut map = self.0.write();
+        let sources = map.entry(path.clone()).or_default();
+        if items.is_empty() {
+            sources.remove(source);
+            if sources.is_empty() {
+                map.remove(path);
+            }
+        } else {
+            sources.insert(source.to_owned(), items);
+        }
+    }
+
+    /// Every file's diagnostics as one entry per producer.
+    pub fn problems(&self) -> Vec<(PathBuf, String, Vec<Diagnostic>)> {
+        let map = self.0.read();
+        map.iter()
+            .flat_map(|(path, sources)| {
+                sources.iter().map(move |(source, items)| (path.clone(), source.clone(), items.clone()))
+            })
+            .collect()
+    }
+
+    pub fn file(&self, path: &PathBuf) -> BTreeMap<String, Vec<Diagnostic>> {
+        self.0.read().get(path).cloned().unwrap_or_default()
+    }
+
+    /// Drops the files under `root` (their project closed; the producers will re-report
+    /// on open). Returns the number of files removed.
+    pub fn forget_root(&self, root: &PathBuf) -> usize {
+        let mut map = self.0.write();
+        let before = map.len();
+        map.retain(|path, _| !path.starts_with(root));
+        before - map.len()
+    }
+}
+
+/// Records `Diagnostics` events, then delivers them as usual.
+pub struct RecordingSink {
+    pub inner: SharedSink,
+    pub store: Arc<DiagnosticsStore>,
+}
+
+impl EventSink for RecordingSink {
+    fn emit(&self, event: IdeEvent) {
+        if let IdeEvent::Diagnostics { path, source, items } = &event {
+            self.store.replace(&path.0.clone(), source, items.clone());
+        }
+        self.inner.emit(event);
+    }
+}
+
+/// A sink whose diagnostics are recorded; the store outlives every project.
+pub type RecordSinkFactory = Box<dyn Fn(&str) -> SharedSink + Send + Sync>;
+
+/// Wraps a sink factory so every sink it creates records diagnostics.
+pub fn recording_sink_factory(store: Arc<DiagnosticsStore>, inner: crate::SinkFactory) -> crate::SinkFactory {
+    Box::new(move |window| {
+        let inner = inner(window);
+        Arc::new(RecordingSink { inner, store: store.clone() }) as SharedSink
+    })
+}

crates/ide-host/src/lib.rs

@@ -5,6 +5,7 @@
 
 pub mod agent_secrets;
 pub mod data_dirs;
+pub mod diagnostics_store;
 pub mod environment;
 mod formatter;
 mod java_runtime;
@@ -58,6 +59,9 @@ pub struct HostConfig {
 pub struct Host {
     pub(crate) mcp_executable: RwLock<Option<PathBuf>>,
     plugin_host: RwLock<std::sync::Weak<plugins::PluginHost>>,
+    /// Every `Diagnostics` event the host ever emitted, per file and producer:
+    /// the snapshot plugins read (`problems`), independent of windows and reports.
+    pub diagnostics: Arc<diagnostics_store::DiagnosticsStore>,
     pub mcp_reports: mcp::Reports,
     pub mcp_requests: mcp::Requests,
     /// Commands agents run in the Run tool window (`run_command`).
@@ -135,12 +139,16 @@ impl Host {
             runtime,
             project_environment,
         } = config;
+        // Every sink the host hands out records diagnostics into the shared store first.
+        let diagnostics: Arc<diagnostics_store::DiagnosticsStore> = Arc::default();
+        let sink_for: SinkFactory = diagnostics_store::recording_sink_factory(diagnostics.clone(), sink_for);
         let global_settings = SettingsStore::load(&config_dir, None);
         let ssh = Arc::new(ide_ssh::SshManager::new(data_dir.join("ssh-passwords.json")));
         ssh.set_configs(global_settings.effective().ssh.configs);
         let host = Self {
             plugin_host: RwLock::default(),
             mcp_executable: RwLock::default(),
+            diagnostics,
             mcp_reports: Default::default(),
             mcp_requests: Default::default(),
             mcp_agent_runs: Default::default(),
@@ -180,6 +188,7 @@ impl Host {
             open_locks: Default::default(),
         };
         host.apply_proxy();
+        ops::agent::move_user_mcp_values(&host);
         host
     }
 
@@ -287,6 +296,9 @@ impl Host {
         }
         project.files_events_active.store(false, std::sync::atomic::Ordering::Release);
         project.plugin_diagnostics.close();
+        // The producers will re-report when a project reopens; until then the snapshot
+        // must not answer for files whose project is gone.
+        self.diagnostics.forget_root(&project.root);
         if let Some(plugins) = plugins::editor_plugin_host() {
             plugins.invalidate_client_navigation(&project.root, Some(window), None);
             plugins.set_active_file(window, None);

crates/ide-host/src/mcp/edit.rs

@@ -87,7 +87,7 @@ async fn create_or_replace(call: &Call, path: PathBuf, text: Option<String>, ove
         return Ok(());
     }
     let edit = crate::ops::lsp::prepare_workspace_edit(&call.host, call.window(), edit).await?;
-    crate::ops::lsp::apply_workspace_edit(&call.host, call.window(), edit).await
+    crate::ops::lsp::apply_agent_workspace_edit(&call.host, call.window(), edit).await
 }
 
 /// The open document of `path`, or a transient one (`true`: close it after use).
@@ -317,7 +317,7 @@ async fn apply_op(call: &Call, op: FileOp, notes: &mut Vec<String>) -> IdeResult
                 preconditions: Vec::new(),
             };
             let edit = crate::ops::lsp::prepare_workspace_edit(&host, call.window(), edit).await?;
-            crate::ops::lsp::apply_workspace_edit(&host, call.window(), edit).await
+            crate::ops::lsp::apply_agent_workspace_edit(&host, call.window(), edit).await
         }
         FileOp::Update { path: first, move_to, hunks, or } => {
             // A plain diff's other names count when its `+++` path does not exist.
@@ -400,7 +400,7 @@ async fn apply_op(call: &Call, op: FileOp, notes: &mut Vec<String>) -> IdeResult
                 edit.files.push(FileEdit::Rename { from: path.into(), to: to.into() });
             }
             let edit = crate::ops::lsp::prepare_workspace_edit(&host, call.window(), edit).await?;
-            crate::ops::lsp::apply_workspace_edit(&host, call.window(), edit).await?;
+            crate::ops::lsp::apply_agent_workspace_edit(&host, call.window(), edit).await?;
             if dirty {
                 notes.push(format!("{shown}: patched the unsaved editor buffer"));
             }

crates/ide-host/src/mcp/edit/rename.rs

@@ -385,7 +385,7 @@ targetIndex, or narrow the call with a contextSnippet that shows the one you mea
         _ => None,
     });
     let (h, w) = (host.clone(), window.to_owned());
-    let written = crate::ops::lsp::apply_workspace_edit(&h, &w, edit).await;
+    let written = crate::ops::lsp::apply_agent_workspace_edit(&h, &w, edit).await;
     if let Err(e) = written {
         let hint = format!("The rename stopped while it wrote. {} Read the files again before you retry.", e.message);
         return Ok(RenameResult::failed("write_failed", hint).with_symbol(symbol));

crates/ide-host/src/ops/agent.rs

@@ -2,6 +2,7 @@
 //! window they run on the host, next to the project they work on.
 use super::{Channel, Emit};
 use crate::Host;
+use crate::agent_secrets::{AgentSecrets, Kept};
 use crate::rpc::Dispatcher;
 use ide_agent::registry::{AgentRegistry, RegistryPaths};
 use ide_agent::{
@@ -342,8 +343,77 @@ pub async fn accept_changes(
 
 type McpServerMap = std::collections::BTreeMap<String, ide_core::settings::AgentMcpServer>;
 
+/// Where the values of the user's MCP servers are kept in [`AgentSecrets`]. A project's own
+/// servers keep their values in the project's file, where the project shares them.
+const USER_MCP_VALUES: &str = "mcp/user/";
+
+/// Every environment variable and header value of `map`, by its key in [`AgentSecrets`].
+fn mcp_values(map: &mut McpServerMap) -> Vec<(String, &mut String)> {
+    let part = |s: &str| s.replace('%', "%25").replace('/', "%2F");
+    let mut values = Vec::new();
+    for (server, cfg) in map.iter_mut() {
+        for (kind, entries) in [("env", &mut cfg.env), ("header", &mut cfg.headers)] {
+            for (name, value) in entries.iter_mut() {
+                values.push((format!("{USER_MCP_VALUES}{}/{kind}/{}", part(server), part(name)), value));
+            }
+        }
+    }
+    values
+}
+
+fn has_mcp_values(map: &McpServerMap) -> bool {
+    map.values().any(|s| s.env.values().chain(s.headers.values()).any(|v| !v.is_empty()))
+}
+
+/// Fills in the saved values. A value written in the settings file wins: an empty one stands for the saved one.
+fn fill_mcp_values(secrets: &AgentSecrets, map: &mut McpServerMap) {
+    for (key, value) in mcp_values(map) {
+        if value.is_empty()
+            && let Some(saved) = secrets.get(&key)
+        {
+            *value = saved;
+        }
+    }
+}
+
+/// Saves the values of `map` and empties them in it; values of servers and names no
+/// longer in it are forgotten.
+fn take_mcp_values(secrets: &AgentSecrets, map: &mut McpServerMap) -> IdeResult<Kept> {
+    let mut kept = Kept::Store;
+    let mut current = HashSet::new();
+    for (key, value) in mcp_values(map) {
+        if value.is_empty() {
+            secrets.delete(&key);
+        } else if secrets.get(&key).as_deref() != Some(value.as_str()) && secrets.set(&key, value)? == Kept::LocalFile {
+            kept = Kept::LocalFile;
+        }
+        value.clear();
+        current.insert(key);
+    }
+    for key in secrets.keys(USER_MCP_VALUES) {
+        if !current.contains(&key) {
+            secrets.delete(&key);
+        }
+    }
+    Ok(kept)
+}
+
+/// Values written into the user settings (by hand, by an older version, by an import) move to [`AgentSecrets`].
+pub fn move_user_mcp_values(host: &Host) {
+    let mut user = host.global_settings.effective().agents.mcp_servers;
+    if !has_mcp_values(&user) {
+        return;
+    }
+    fill_mcp_values(&host.agent_secrets, &mut user);
+    if let Err(e) = persist_mcp_map(host, None, McpScope::User, &user) {
+        tracing::warn!("MCP servers: could not move values out of the user settings: {}", e.message);
+    }
+}
+
 fn mcp_maps(host: &Host, window: &str) -> (McpServerMap, McpServerMap, Option<std::sync::Arc<crate::Project>>) {
-    let user = host.global_settings.effective().agents.mcp_servers;
+    move_user_mcp_values(host);
+    let mut user = host.global_settings.effective().agents.mcp_servers;
+    fill_mcp_values(&host.agent_secrets, &mut user);
     let project = host.project(window).ok().filter(|p| !p.light);
     let workspace = project
         .as_ref()
@@ -358,10 +428,15 @@ fn persist_mcp_map(
     scope: McpScope,
     map: &McpServerMap,
 ) -> IdeResult<()> {
+    let mut map = map.clone();
+    let kept = match scope {
+        McpScope::User => take_mcp_values(&host.agent_secrets, &mut map)?,
+        McpScope::Workspace => Kept::Store,
+    };
     let value = if map.is_empty() {
         serde_json::Value::Null
     } else {
-        serde_json::to_value(map).map_err(|e| IdeError::invalid(e.to_string()))?
+        serde_json::to_value(&map).map_err(|e| IdeError::invalid(e.to_string()))?
     };
     let event = IdeEvent::SettingsChanged { key: "agents.mcpServers".into() };
     match scope {
@@ -370,6 +445,9 @@ fn persist_mcp_map(
             for p in host.projects() {
                 p.settings.reload();
                 p.sink.emit(event.clone());
+                if kept == Kept::LocalFile {
+                    host.agent_secrets.notify_kept_locally(&p.sink);
+                }
             }
         }
         McpScope::Workspace => {
@@ -418,15 +496,17 @@ fn listed(
     ide_agent::mcp::servers_from_settings(user, &workspace)
 }
 
-/// The MCP servers agent sessions of the project at `root` get: the user's, and the project's the
-/// user turned on.
+/// The MCP servers agent sessions of the project at `root` get: the user's, values filled in, and
+/// the project's the user turned on.
 pub(crate) fn session_mcp_servers(
     settings: &ide_workspace::SettingsStore,
     approvals: &crate::trust::McpServerApprovals,
+    secrets: &AgentSecrets,
     root: &std::path::Path,
 ) -> Vec<McpServer> {
     use ide_workspace::settings::SettingsScope;
-    let user = settings.layer(SettingsScope::Global).agents.mcp_servers;
+    let mut user = settings.layer(SettingsScope::Global).agents.mcp_servers;
+    fill_mcp_values(secrets, &mut user);
     let workspace = approvals.apply(root, settings.layer(SettingsScope::Project).agents.mcp_servers);
     ide_agent::mcp::servers_from_settings(&user, &workspace)
 }
@@ -593,6 +673,7 @@ mod tests {
 
     #[test]
     fn sessions_get_the_users_servers_and_the_projects_turned_on_ones() {
+        ide_ssh::secrets::testing::use_memory_store();
         let tmp = tempfile::tempdir().unwrap();
         let (config, root) = (tmp.path().join("config"), tmp.path().join("project"));
         std::fs::create_dir_all(&config).unwrap();
@@ -605,6 +686,7 @@ mod tests {
         .unwrap();
         let settings = ide_workspace::SettingsStore::load(&config, Some(&root));
         let approvals = crate::trust::McpServerApprovals::load(&tmp.path().join("data"));
+        let secrets = AgentSecrets::new(&tmp.path().join("data"));
         let on = |servers: Vec<McpServer>| -> Vec<(McpScope, String, String)> {
             servers
                 .into_iter()
@@ -613,13 +695,27 @@ mod tests {
                 .collect()
         };
         assert_eq!(
-            on(session_mcp_servers(&settings, &approvals, &root)),
+            on(session_mcp_servers(&settings, &approvals, &secrets, &root)),
             [(McpScope::User, "shared".to_owned(), "user-cmd".to_owned())]
         );
 
+        // A user server's saved values reach the session; the file keeps only the names.
+        std::fs::write(
+            config.join("settings.toml"),
+            "[agents.mcpServers.keyed]\ncommand = \"k\"\nenv = { TOKEN = \"\" }\n",
+        )
+        .unwrap();
+        secrets.set("mcp/user/keyed/env/TOKEN", "saved-user").unwrap();
+        settings.reload();
+        let keyed = session_mcp_servers(&settings, &approvals, &secrets, &root);
+        let keyed = keyed.iter().find(|s| s.name == "keyed").unwrap();
+        assert_eq!(keyed.env[0].value, "saved-user");
+        std::fs::write(config.join("settings.toml"), "[agents.mcpServers.shared]\ncommand = \"user-cmd\"\n").unwrap();
+        settings.reload();
+
         let extra = settings.layer(ide_workspace::settings::SettingsScope::Project).agents.mcp_servers["extra"].clone();
         approvals.approve(&root, "extra", &extra).unwrap();
-        assert!(on(session_mcp_servers(&settings, &approvals, &root)).contains(&(
+        assert!(on(session_mcp_servers(&settings, &approvals, &secrets, &root)).contains(&(
             McpScope::Workspace,
             "extra".to_owned(),
             "extra".to_owned()

crates/ide-host/src/ops/build.rs

@@ -15,6 +15,7 @@ use ide_build::{BuildModel, BuildTool, SyncOptions, SyncProgress};
 use ide_core::settings::Settings;
 use ide_core::{DocId, FileEdit, IdeError, IdeEvent, IdeResult, Location, Pos, Range, RequestId, WorkspaceEdit};
 use std::path::Path;
+use std::sync::Arc;
 
 fn join_err(e: tokio::task::JoinError) -> IdeError {
     IdeError::internal(e.to_string())
@@ -330,21 +331,61 @@ pub async fn build_sync(
     // holds for Gradle: it reuses its cached classpath on restart, so a
     // dependency added to `build.gradle` stays unresolved until told to sync.
     let lsp = project.lsp.clone();
+    let documents = project.documents.clone();
     tokio::spawn(async move {
         if profiles_changed {
             // jdtls takes the profiles from its Maven settings (see `ide_sdk::maven_profiles`).
             lsp.reconfigure().await;
         }
+        let first = updates.first().cloned();
         for file in updates {
             let uri = ide_lsp::path_to_uri_string(&file);
             if let Err(e) = lsp.java_update_project_configs(&file, vec![uri]).await {
                 tracing::debug!("java/projectConfigurationsUpdate: {e}");
             }
         }
+        let changed = {
+            let lsp = lsp.clone();
+            tokio::task::spawn_blocking(move || lsp.changed_library_archives()).await.unwrap_or_default()
+        };
+        if let Some(file) = first
+            && let Err(e) = lsp.java_refresh_archives(&file, &changed).await
+        {
+            tracing::debug!("openidea.java.refreshArchives: {e}");
+        }
+        refresh_library_classes(&lsp, &documents).await;
     });
     Ok(model)
 }
 
+/// Open library classes whose jar was replaced in place (a SNAPSHOT installed
+/// again keeps its path) show the new contents, like a reopened one.
+async fn refresh_library_classes(lsp: &Arc<ide_lsp::LspManager>, documents: &Arc<ide_workspace::Documents>) {
+    let changed = {
+        let (lsp, documents) = (lsp.clone(), documents.clone());
+        tokio::task::spawn_blocking(move || {
+            documents
+                .open_documents()
+                .into_iter()
+                .filter_map(|doc| Some((doc, documents.virtual_uri(doc).ok().flatten()?)))
+                .filter(|(_, uri)| lsp.library_class_changed(uri))
+                .collect::<Vec<_>>()
+        })
+        .await
+        .unwrap_or_default()
+    };
+    for (doc, uri) in changed {
+        match lsp.virtual_document(&uri).await {
+            Ok(vd) => {
+                if let Err(e) = documents.replace_virtual(doc, &vd.text, &vd.encoding, vd.has_bom) {
+                    tracing::debug!("refreshing {uri}: {e}");
+                }
+            }
+            Err(e) => tracing::debug!("refreshing {uri}: {e}"),
+        }
+    }
+}
+
 /// The POM declaring `dependency` for the Maven module `pom` (project-relative): the
 /// module's own, else its nearest parent in the project; its path, text and declaration.
 fn declaring_pom(
@@ -985,6 +1026,38 @@ mod build_tool_settings_tests {
         }
     }
 
+    /// Changing Project JDK updates the next Maven build without reopening the project.
+    #[test]
+    fn changing_project_jdk_updates_the_next_maven_build() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        std::fs::write(
+            root.join("pom.xml"),
+            r#"<project><modelVersion>4.0.0</modelVersion><groupId>test</groupId><artifactId>app</artifactId><version>1</version></project>"#,
+        )
+        .unwrap();
+        for (name, version) in [("jdk8", "1.8"), ("jdk21", "21")] {
+            let home = root.join(name);
+            std::fs::create_dir_all(home.join("bin")).unwrap();
+            std::fs::write(home.join("bin").join(if cfg!(windows) { "java.exe" } else { "java" }), "").unwrap();
+            std::fs::write(home.join("release"), format!("JAVA_VERSION=\"{version}\"\n")).unwrap();
+        }
+
+        let mut settings = Settings::default();
+        settings.languages.java.maven.runner_jre.clear();
+        for name in ["jdk8", "jdk21"] {
+            settings.languages.java.jdk = name.into();
+            let expected = root.join(name);
+            let model = load(&root, &root.join("cache"), &settings);
+            assert_eq!(model.maven.as_ref().unwrap().projects[0].env["JAVA_HOME"], expected.to_string_lossy());
+            let plan = compile::plan(&root, &model, BuildKind::Build, None, None).unwrap();
+            assert!(!plan.steps.is_empty());
+            for step in plan.steps {
+                assert_eq!(step.env["JAVA_HOME"], expected.to_string_lossy());
+            }
+        }
+    }
+
     #[test]
     fn model_for_sync_tasks_and_compile_uses_gradle_settings() {
         let tmp = tempfile::tempdir().unwrap();
@@ -1019,7 +1092,6 @@ mod maven_completion_tests {
     use ide_build::maven::completion::PomCompletionKind;
     use ide_core::CancellationToken;
     use ide_workspace::dependencies::DependencyVersionSource;
-    use std::sync::Arc;
 
     /// Cache answers the test plants before completing, so the op's Central
     /// lookups hit the session cache and the network is never reached.

crates/ide-host/src/ops/deploy.rs

@@ -188,8 +188,14 @@ pub async fn remote_download_into(
     r
 }
 
-pub async fn deploy_test_connection(state: &Host, connection: FsConnection, path: String) -> IdeResult<()> {
-    state.remote.test_connection(&connection, &path).await
+/// `password`: an FTP password typed in the settings but not applied yet.
+pub async fn deploy_test_connection(
+    state: &Host,
+    connection: FsConnection,
+    path: String,
+    password: Option<String>,
+) -> IdeResult<()> {
+    state.remote.test_connection_with(&connection, &path, password).await
 }
 
 pub(crate) fn register(d: &mut crate::rpc::Dispatcher) {
@@ -231,6 +237,6 @@ pub(crate) fn register(d: &mut crate::rpc::Dispatcher) {
         remote_rename(&c.host, c.arg("connection")?, c.arg("from")?, c.arg("to")?).await
     });
     d.add("deploy_test_connection", |c| async move {
-        deploy_test_connection(&c.host, c.arg("connection")?, c.arg("path")?).await
+        deploy_test_connection(&c.host, c.arg("connection")?, c.arg("path")?, c.arg("password")?).await
     });
 }

crates/ide-host/src/ops/java.rs

@@ -96,18 +96,19 @@ async fn resolve_launch(
     let cancel = cancel.clone();
     tokio::task::spawn_blocking(move || {
         let _external_build = external_build;
+        let local_repo = ide_sdk::apply::maven_local_repository(&project.root, &settings);
         let built = if delegated {
-            let policy = delegated_policy(policy, prefer_maven, info.error_count);
+            let rebuild_on_jdt_errors = rebuild_on_jdt_errors(policy, prefer_maven, info.error_count);
             let outputs = project.java_launch_snapshots.lock().build(
                 &project.root,
                 &model,
                 &module,
-                cache::BuildOptions { test, policy },
-                ide_sdk::apply::maven_local_repository(&project.root, &settings),
+                cache::BuildOptions { test, policy, rebuild_on_jdt_errors },
+                local_repo.clone(),
                 &cancel,
             )?;
             let copies = use_snapshot(&mut info, &outputs.originals, &outputs.snapshot);
-            apply_external_build_result(&mut info, outputs.failure, policy == BuildPolicy::Rebuild);
+            apply_external_build_result(&mut info, outputs.failure, outputs.authoritative);
             copies
         } else if external {
             let built = compile::build_for_launch(&project.root, &model, &module, test, build_kind, &cancel)?;
@@ -123,10 +124,22 @@ async fn resolve_launch(
             Vec::new()
         };
         let mut class_paths: Vec<String> = built.iter().map(|p| p.to_string_lossy().into_owned()).collect();
-        for p in std::mem::take(&mut info.class_paths) {
-            if !class_paths.iter().any(|c| same_entry(c, &p, cfg!(windows))) {
-                class_paths.push(p);
-            }
+        if delegated {
+            // m2e runs inside jdtls on the server JDK and can resolve a different
+            // Maven profile/classifier than the module build. Ask the same Maven
+            // process that built the module for its runtime/test dependencies.
+            let maven_cp = compile::module_classpath(
+                &project.root,
+                &model,
+                &module,
+                test,
+                local_repo,
+                &project.build_cache_dir(),
+                &cancel,
+            );
+            merge_maven_launch_classpath(&mut class_paths, &mut info, maven_cp)?;
+        } else {
+            append_unique_class_paths(&mut class_paths, std::mem::take(&mut info.class_paths));
         }
         info.class_paths = class_paths;
         apply_library_classpath(&mut info, &project.root, &settings.project_structure.libraries, test);
@@ -191,21 +204,18 @@ async fn resolve_launch(
 /// With Settings › Maven › Delegate IDE build/run actions to Maven, javac's verdict replaces
 /// JDT's. Classes JDT wrote for sources with errors look up to date to Maven's incremental
 /// compiler, so a launch JDT reports errors for recompiles everything.
-fn delegated_policy(policy: BuildPolicy, prefer_maven: bool, jdt_errors: u32) -> BuildPolicy {
-    if prefer_maven && jdt_errors > 0 && matches!(policy, BuildPolicy::Automatic | BuildPolicy::Make) {
-        BuildPolicy::Rebuild
-    } else {
-        policy
-    }
+fn rebuild_on_jdt_errors(policy: BuildPolicy, prefer_maven: bool, jdt_errors: u32) -> bool {
+    prefer_maven && jdt_errors > 0 && matches!(policy, BuildPolicy::Automatic | BuildPolicy::Make)
 }
 
-fn apply_external_build_result(info: &mut JavaLaunchInfo, failure: Option<String>, clean: bool) {
+fn apply_external_build_result(info: &mut JavaLaunchInfo, failure: Option<String>, authoritative: bool) {
     info.build = Some(if let Some(failure) = failure {
         info.hints.push(failure);
         JavaBuildStatus::Failed
-    } else if clean {
-        // A clean external build recompiled every source; JDT's diagnostics still describe
-        // the previous output (and reject sources javac accepts, e.g. a package mismatch).
+    } else if authoritative {
+        // A clean rebuild or a fingerprint-verified snapshot is authoritative. JDT diagnostics
+        // may describe an older output or its own classpath, so they must not mark this launch
+        // as failed after Maven has produced usable classes.
         info.errors.clear();
         info.error_count = 0;
         JavaBuildStatus::Succeeded
@@ -286,6 +296,44 @@ fn same_entry(a: &str, b: &str, windows: bool) -> bool {
     a == b || entry_key(a, windows) == entry_key(b, windows)
 }
 
+/// Merge the Maven launch classpath without turning a recoverable probe failure into a
+/// failed launch. Cancellation still propagates; ordinary failures keep jdtls' classpath
+/// and leave the reason in the run console.
+fn merge_maven_launch_classpath(
+    class_paths: &mut Vec<String>,
+    info: &mut JavaLaunchInfo,
+    classpath: IdeResult<String>,
+) -> IdeResult<()> {
+    match classpath {
+        Ok(classpath) => {
+            append_unique_class_paths(
+                class_paths,
+                std::env::split_paths(&classpath).map(|path| path.to_string_lossy().into_owned()),
+            );
+            Ok(())
+        }
+        Err(error) if error.kind == ErrorKind::Cancelled => Err(error),
+        Err(error) => {
+            info.hints.push(format!(
+                "Maven launch classpath resolution failed; using the Java language server classpath instead:\n{}",
+                error.message
+            ));
+            append_unique_class_paths(class_paths, std::mem::take(&mut info.class_paths));
+            Ok(())
+        }
+    }
+}
+
+/// Append entries without changing their precedence; `same_entry` also catches
+/// Windows case-insensitive duplicates that would otherwise lengthen the command.
+fn append_unique_class_paths(class_paths: &mut Vec<String>, entries: impl IntoIterator<Item = String>) {
+    for entry in entries {
+        if !class_paths.iter().any(|existing| same_entry(existing, &entry, cfg!(windows))) {
+            class_paths.push(entry);
+        }
+    }
+}
+
 fn use_snapshot(info: &mut JavaLaunchInfo, built: &[PathBuf], snapshot: &std::path::Path) -> Vec<PathBuf> {
     use_snapshot_on(info, built, snapshot, cfg!(windows))
 }
@@ -410,14 +458,36 @@ mod tests {
 
     #[test]
     fn delegated_launches_with_jdt_errors_recompile_with_maven() {
-        assert_eq!(delegated_policy(BuildPolicy::Make, true, 1), BuildPolicy::Rebuild);
-        assert_eq!(delegated_policy(BuildPolicy::Automatic, true, 2), BuildPolicy::Rebuild);
-        assert_eq!(delegated_policy(BuildPolicy::Make, true, 0), BuildPolicy::Make);
-        assert_eq!(delegated_policy(BuildPolicy::Make, false, 1), BuildPolicy::Make);
-        assert_eq!(
-            delegated_policy(BuildPolicy::MakeAndContinueOnErrors, true, 1),
-            BuildPolicy::MakeAndContinueOnErrors
-        );
+        assert!(rebuild_on_jdt_errors(BuildPolicy::Make, true, 1));
+        assert!(rebuild_on_jdt_errors(BuildPolicy::Automatic, true, 2));
+        assert!(!rebuild_on_jdt_errors(BuildPolicy::Make, true, 0));
+        assert!(!rebuild_on_jdt_errors(BuildPolicy::Make, false, 1));
+        assert!(!rebuild_on_jdt_errors(BuildPolicy::MakeAndContinueOnErrors, true, 1));
+    }
+
+    #[test]
+    fn maven_classpath_probe_failure_falls_back_to_jdtls_classpaths() {
+        let maven = std::env::join_paths(["maven.jar", "snapshot.jar"]).unwrap().to_string_lossy().into_owned();
+        let mut class_paths = vec!["snapshot.jar".to_owned()];
+        let mut info =
+            JavaLaunchInfo { class_paths: vec!["snapshot.jar".into(), "jdtls.jar".into()], ..Default::default() };
+        merge_maven_launch_classpath(&mut class_paths, &mut info, Ok(maven)).unwrap();
+        assert_eq!(class_paths, ["snapshot.jar", "maven.jar"]);
+
+        merge_maven_launch_classpath(&mut class_paths, &mut info, Err(IdeError::internal("offline dependency")))
+            .unwrap();
+        assert_eq!(class_paths, ["snapshot.jar", "maven.jar", "jdtls.jar"]);
+        assert!(info.hints[0].contains("offline dependency"), "{:?}", info.hints);
+    }
+
+    #[test]
+    fn cancelled_maven_classpath_probe_propagates_without_fallback() {
+        let mut class_paths = vec!["snapshot.jar".to_owned()];
+        let mut info = JavaLaunchInfo { class_paths: vec!["jdtls.jar".into()], ..Default::default() };
+        let error = merge_maven_launch_classpath(&mut class_paths, &mut info, Err(IdeError::cancelled())).unwrap_err();
+        assert_eq!(error.kind, ErrorKind::Cancelled);
+        assert_eq!(class_paths, ["snapshot.jar"]);
+        assert!(info.hints.is_empty());
     }
 
     #[test]
@@ -461,7 +531,7 @@ mod tests {
     }
 
     #[test]
-    fn clean_external_build_clears_stale_jdt_errors() {
+    fn authoritative_external_result_clears_stale_jdt_errors() {
         let mut info = JavaLaunchInfo {
             error_count: 7,
             errors: vec![ide_lsp::jdtls::JavaCompileError {

crates/ide-host/src/ops/java/cache.rs

@@ -14,6 +14,10 @@ pub(super) struct Outputs {
     pub originals: Vec<PathBuf>,
     #[serde(skip)]
     pub failure: Option<String>,
+    /// Whether this result replaces jdtls diagnostics with a clean Maven build or a
+    /// verified snapshot. It is runtime-only because reuse is determined per launch.
+    #[serde(skip)]
+    pub authoritative: bool,
 }
 
 impl Outputs {
@@ -42,6 +46,9 @@ pub(super) fn has_record(root: &Path, cache: &Path, module: &Path) -> bool {
 pub(super) struct BuildOptions {
     pub test: bool,
     pub policy: BuildPolicy,
+    /// A JDT error makes a cache miss rebuild, but it must not prevent an unchanged
+    /// snapshot from being reused on the next launch.
+    pub rebuild_on_jdt_errors: bool,
 }
 
 /// Owned by Project: running JVMs may still load superseded outputs until it drops.
@@ -75,7 +82,7 @@ impl Session {
         cancel: &CancellationToken,
     ) -> IdeResult<Outputs> {
         self.initialize();
-        let BuildOptions { test, policy } = options;
+        let BuildOptions { test, policy, rebuild_on_jdt_errors } = options;
         let cache = &self.cache;
         let record =
             record_path(root, cache, module, test).ok_or_else(|| IdeError::internal("launch outside project"))?;
@@ -115,8 +122,14 @@ impl Session {
             && outputs.reusable(&before, &snapshots)
         {
             tracing::info!(module = %module.display(), test, "Reusing Maven launch snapshot");
-            return Ok(previous.unwrap());
+            let mut outputs = previous.unwrap();
+            outputs.authoritative = true;
+            return Ok(outputs);
         }
+        // JDT can report errors from its own classpath while the last Maven snapshot is
+        // still valid. Reuse that snapshot first; only a cache miss needs the expensive
+        // clean rebuild that replaces JDT's error-stub classes.
+        let policy = if rebuild_on_jdt_errors { BuildPolicy::Rebuild } else { policy };
         // 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())?;
@@ -156,7 +169,13 @@ impl Session {
         if cancel.is_cancelled() {
             return Err(IdeError::cancelled());
         }
-        let mut outputs = Outputs { fingerprint: None, snapshot, originals, failure: built.failure };
+        let mut outputs = Outputs {
+            fingerprint: None,
+            snapshot,
+            originals,
+            failure: built.failure,
+            authoritative: policy == BuildPolicy::Rebuild,
+        };
         if outputs.failure.is_none() && before.is_some() && before == after {
             outputs.fingerprint = before;
             fs::create_dir_all(record.parent().unwrap())?;
@@ -334,6 +353,48 @@ mod tests {
         );
     }
 
+    #[test]
+    fn jdt_errors_reuse_an_unchanged_snapshot_and_rebuild_only_on_a_cache_miss() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cancel = CancellationToken::new();
+        let mut session = Session::new(root.join("cache"));
+        let first = session.build(root, &model, root, BuildOptions::default(), None, &cancel).unwrap();
+        assert!(!first.authoritative);
+
+        let reused = session
+            .build(
+                root,
+                &model,
+                root,
+                BuildOptions { rebuild_on_jdt_errors: true, ..Default::default() },
+                None,
+                &cancel,
+            )
+            .unwrap();
+        assert_eq!(reused.snapshot, first.snapshot);
+        assert!(reused.authoritative);
+        assert_eq!(fs::read_to_string(root.join("calls")).unwrap().lines().count(), 1);
+
+        fs::write(root.join("src/main/kotlin/Main.kt"), "updated").unwrap();
+        let rebuilt = session
+            .build(
+                root,
+                &model,
+                root,
+                BuildOptions { rebuild_on_jdt_errors: true, ..Default::default() },
+                None,
+                &cancel,
+            )
+            .unwrap();
+        assert_ne!(rebuilt.snapshot, first.snapshot);
+        assert!(rebuilt.authoritative);
+        let calls = fs::read_to_string(root.join("calls")).unwrap();
+        assert_eq!(calls.lines().count(), 2);
+        assert!(calls.lines().last().unwrap().contains("clean"));
+    }
+
     #[test]
     fn successful_snapshots_reuse_across_close_and_rebuild_for_changes_missing_outputs_or_failure() {
         let dir = tempfile::tempdir().unwrap();
@@ -483,7 +544,13 @@ mod tests {
         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(), failure: None };
+        let outputs = Outputs {
+            fingerprint: None,
+            snapshot: retained.clone(),
+            originals: Vec::new(),
+            failure: None,
+            authoritative: false,
+        };
         fs::write(record, serde_json::to_vec(&outputs).unwrap()).unwrap();
         let mut session = Session::new(cache);
         session.initialize();

crates/ide-host/src/ops/lsp.rs

@@ -309,9 +309,13 @@ pub async fn lsp_signature_help(host: &Host, window: &str, doc: DocId, pos: Pos)
 
 pub async fn lsp_goto(host: &Host, window: &str, doc: DocId, pos: Pos, kind: GotoKind) -> IdeResult<Vec<Location>> {
     let target = position_document(host, window, doc, pos).await?;
+    // ⌘B on a declaration shows its usages, also when a plugin's index links the name elsewhere
+    // (a MyBatis mapper method to its XML statement): the server's answer comes along for the
+    // editor to tell.
     if target == doc
         && kind == GotoKind::Definition
         && let Some(plugins) = crate::plugins::editor_plugin_host()
+        && !on_declaration_name(host, window, doc, pos).await
     {
         let project = host.project(window)?;
         // A notebook cell is a language-server document only: no plugin navigates in it.
@@ -352,6 +356,30 @@ pub async fn lsp_goto(host: &Host, window: &str, doc: DocId, pos: Pos, kind: Got
     definition_targets(result, found, in_string)
 }
 
+/// Whether the syntax tree puts the identifier at `pos` as a declaration's name (`int f()`'s `f`).
+async fn on_declaration_name(host: &Host, window: &str, doc: DocId, pos: Pos) -> bool {
+    let Ok(project) = host.project(window) else { return false };
+    blocking(move || {
+        let snap = project.documents.text_snapshot(doc)?;
+        if snap.large {
+            return Ok(false);
+        }
+        let s = ide_syntax::Snapshot::doc(doc, snap.version, &snap.language, &snap.text);
+        let cancel = ide_core::CancellationToken::new();
+        let Ok(Some(at)) = project.structure.node_at(&s, Range::new(pos, pos), &cancel) else { return Ok(false) };
+        Ok(is_declaration_name(&at))
+    })
+    .await
+    .unwrap_or(false)
+}
+
+fn is_declaration_name(at: &ide_syntax::NodeAt) -> bool {
+    at.node.field.as_deref() == Some("name")
+        && at.ancestors.first().is_some_and(|parent| {
+            ["declaration", "definition", "declarator"].iter().any(|kind| parent.kind.ends_with(kind))
+        })
+}
+
 async fn in_string_literal(host: &Host, window: &str, doc: DocId, pos: Pos) -> bool {
     let Ok(project) = host.project(window) else { return false };
     blocking(move || {
@@ -1483,23 +1511,38 @@ pub async fn lsp_restart_named(host: &Host, name: &str) -> IdeResult<()> {
 pub async fn apply_workspace_edit(host: &Host, window: &str, edit: WorkspaceEdit) -> IdeResult<()> {
     let project = host.project(window)?;
     blocking(move || {
-        // Multi-file refactorings leave a Local History point to go back to.
-        let paths: Vec<&std::path::Path> = edit
-            .files
-            .iter()
-            .filter_map(|f| match f {
-                ide_core::FileEdit::Edit { path, .. } => Some(&**path),
-                _ => None,
-            })
-            .collect();
-        if edit.files.len() > 1 {
-            project.record_before_refactoring(&paths, "Apply changes");
-        }
+        record_before_multi_file_edit(&project, &edit);
         apply_edit(&project.documents, &edit)
     })
     .await
 }
 
+/// [`apply_workspace_edit`] for the MCP server's tools: undoable the same way, but the UI does
+/// not announce it as a refactoring.
+pub async fn apply_agent_workspace_edit(host: &Host, window: &str, edit: WorkspaceEdit) -> IdeResult<()> {
+    let project = host.project(window)?;
+    blocking(move || {
+        record_before_multi_file_edit(&project, &edit);
+        project.documents.apply_agent_workspace_edit(&edit)
+    })
+    .await
+}
+
+/// Multi-file edits leave a Local History point to go back to.
+fn record_before_multi_file_edit(project: &crate::Project, edit: &WorkspaceEdit) {
+    let paths: Vec<&std::path::Path> = edit
+        .files
+        .iter()
+        .filter_map(|f| match f {
+            ide_core::FileEdit::Edit { path, .. } => Some(&**path),
+            _ => None,
+        })
+        .collect();
+    if edit.files.len() > 1 {
+        project.record_before_refactoring(&paths, "Apply changes");
+    }
+}
+
 pub async fn prepare_workspace_edit(host: &Host, window: &str, mut edit: WorkspaceEdit) -> IdeResult<WorkspaceEdit> {
     let project = host.project(window)?;
     blocking(move || {
@@ -2121,6 +2164,24 @@ mod tests {
         assert_eq!(paths(definition_targets(Ok(vec![helper, guess]), Vec::new(), false)), ["/p/app/helpers.php"]);
     }
 
+    #[test]
+    fn declaration_names_are_told_apart_from_uses() {
+        let syntax = std::sync::Arc::new(ide_language::Syntax::new());
+        let structure = ide_syntax::StructureService::new(std::sync::Arc::new(ide_language::SyntaxCache::new(syntax)));
+        let java = ide_core::LanguageId::new("java");
+        let text = "interface ShareMapper {\n    int batchCancel(List<Long> ids);\n}\nclass S { int f(ShareMapper m) { return m.batchCancel(null); } }\n";
+        let snap = ide_syntax::Snapshot::text(&java, text);
+        let cancel = ide_core::CancellationToken::new();
+        let at = |line, col| {
+            let pos = Pos::new(line, col);
+            is_declaration_name(&structure.node_at(&snap, Range::new(pos, pos), &cancel).unwrap().unwrap())
+        };
+        assert!(at(1, 10), "the mapper method's name");
+        assert!(at(0, 12), "the interface's name");
+        assert!(!at(3, 45), "a call of the method");
+        assert!(!at(1, 4), "its return type");
+    }
+
     #[test]
     fn positions_inside_string_literals_are_told_apart() {
         let syntax = std::sync::Arc::new(ide_language::Syntax::new());

crates/ide-host/src/ops/sdk.rs

@@ -61,13 +61,16 @@ pub async fn sdk_python_project_interpreters(host: &Host, window: &str) -> IdeRe
     host.require_trust(window)?;
     let current = host.project(window).ok().map(|p| p.root.clone());
     let config = host.config_dir.clone();
+    // Probing runs the project's interpreter (and its settings may name any program): only
+    // projects trusted in their own right, not ones last opened in Restricted Mode.
+    let roots: Vec<PathBuf> = ide_workspace::RecentProjects::load(&config)
+        .list()
+        .into_iter()
+        .map(|p| p.path.into_path_buf())
+        .filter(|root| current.as_deref() != Some(root.as_path()))
+        .filter(|root| host.trust.window_trusted(root).unwrap_or(false))
+        .collect();
     tokio::task::spawn_blocking(move || {
-        let roots: Vec<PathBuf> = ide_workspace::RecentProjects::load(&config)
-            .list()
-            .into_iter()
-            .map(|p| p.path.into_path_buf())
-            .filter(|root| current.as_deref() != Some(root.as_path()))
-            .collect();
         // Each project resolves its configured interpreter, else its own virtualenv. The
         // probes run `python`, so keep them off the async runtime and bound how many run at
         // once: the recent list can hold ~30 projects, and each probe starts a process.
@@ -521,6 +524,10 @@ mod tests {
         host.trust.decide(&root, true, false).unwrap();
         host.open_project("main", &root).unwrap();
 
+        // A project last opened in Restricted Mode: its interpreter is never run.
+        host.trust.decide(&other, false, false).unwrap();
+        assert!(sdk_python_project_interpreters(&host, "main").await.unwrap().is_empty());
+        host.trust.decide(&other, true, false).unwrap();
         let list = sdk_python_project_interpreters(&host, "main").await.unwrap();
         assert_eq!(list.len(), 1, "{list:?}");
         assert_eq!(&*list[0].project, other.as_path());

crates/ide-host/src/ops/spell.rs

@@ -47,14 +47,17 @@ pub async fn spell_check(
     let syntax = host.syntax();
     let cancel = host.begin_request(request);
     let result = blocking(move || {
+        let path = project.documents.snapshot(doc)?.path.0.clone();
         let snap = project.documents.text_snapshot(doc)?;
         if snap.large {
-            return Ok(Vec::new());
+            return Ok((path, Vec::new()));
         }
         let regions = if PROSE.contains(&snap.language.as_str()) {
             ide_spell::prose_regions(&snap.text)
         } else {
-            let Some(found) = syntax.spelling_regions(&snap.language, &snap.text) else { return Ok(Vec::new()) };
+            let Some(found) = syntax.spelling_regions(&snap.language, &snap.text) else {
+                return Ok((path, Vec::new()));
+            };
             found
                 .into_iter()
                 .map(|r| Region {
@@ -72,11 +75,32 @@ pub async fn spell_check(
         if cancel.is_cancelled() {
             return Err(IdeError::cancelled());
         }
-        speller(&project).check(&snap.text, &regions, &|| cancel.is_cancelled()).ok_or_else(IdeError::cancelled)
+        let typos =
+            speller(&project).check(&snap.text, &regions, &|| cancel.is_cancelled()).ok_or_else(IdeError::cancelled)?;
+        Ok((path, typos))
     })
     .await;
     host.end_request(request);
-    result
+    // Record the typos in the host's diagnostics snapshot so line-end annotations
+    // see them without waiting for a UI report; the editor still draws from its
+    // own call above, unchanged.
+    if let Ok((path, typos)) = &result {
+        let items: Vec<ide_core::Diagnostic> = typos
+            .iter()
+            .map(|t| ide_core::Diagnostic {
+                range: t.range,
+                severity: ide_core::Severity::Info,
+                message: format!("Typo: In word '{}'", t.word),
+                source: Some("Spelling".into()),
+                code: None,
+                unnecessary: false,
+                deprecated: false,
+                server: None,
+            })
+            .collect();
+        host.diagnostics.replace(path, "Spelling", items);
+    }
+    result.map(|(_, typos)| typos)
 }
 
 /// Replacements for a misspelt `word`, best first (Typo › Change to…).

crates/ide-host/src/plugins/api.rs

@@ -3176,26 +3176,17 @@ impl PluginWorkspace for HostWorkspace {
         Ok(out)
     }
     fn problems(&self, client: &str, path: Option<&Path>) -> Result<Vec<ide_plugin::FileProblems>, HostError> {
+        // The host records every `Diagnostics` event it emits (language servers,
+        // builds, spelling, plugin providers), so this sees a file's problems
+        // whatever window opened it — not just the ones its UI reported.
         let host = self.0.upgrade().ok_or(HostError::Cancelled)?;
-        let root = host.project(client).map_err(failed)?.root.clone();
-        let windows = host.windows_for_root(&root);
+        host.project(client).map_err(failed)?;
         let mut out = Vec::new();
-        for file in host.mcp_reports.problems(&windows) {
-            if path.is_some_and(|p| p != file.path.0) {
+        for (file, source, diagnostics) in host.diagnostics.problems() {
+            if path.is_some_and(|p| p != file) {
                 continue;
             }
-            if ide_plugin::resolve_new_in_root(&root, &to_ipc(&file.path.0)).is_err() {
-                continue;
-            }
-            let mut sources: BTreeMap<String, Vec<ide_core::Diagnostic>> = BTreeMap::new();
-            for d in file.items {
-                sources.entry(d.server.clone().or_else(|| d.source.clone()).unwrap_or_default()).or_default().push(d);
-            }
-            out.extend(sources.into_iter().map(|(source, diagnostics)| ide_plugin::FileProblems {
-                path: to_ipc(&file.path.0),
-                source,
-                diagnostics,
-            }));
+            out.push(ide_plugin::FileProblems { path: to_ipc(&file), source, diagnostics });
         }
         Ok(out)
     }
@@ -3321,6 +3312,8 @@ impl PluginWorkspace for HostWorkspace {
         path: &Path,
         items: Vec<ide_core::Diagnostic>,
     ) -> Result<(), HostError> {
+        // Any open project may publish problems for any file: annotations follow the
+        // file, not the window (an editor can show a file outside every project root).
         let projects = HostWorkspace::projects(self);
         let project = projects
             .iter()
@@ -3332,7 +3325,8 @@ impl PluginWorkspace for HostWorkspace {
                     .iter()
                     .find(|p| crate::project::workspace_member_roots(&p.root).iter().any(|m| path.starts_with(m)))
             })
-            .ok_or_else(|| HostError::Invalid(format!("{} is not in an open project", path.display())))?;
+            .or_else(|| projects.first())
+            .ok_or_else(|| HostError::NotFound("no project is open".into()))?;
         project.sink.emit(ide_core::IdeEvent::Diagnostics {
             path: path.to_path_buf().into(),
             source: format!("plugin:{source}"),
@@ -4135,16 +4129,23 @@ impl PluginApi {
             return Err(HostError::Invalid("reversed decoration range".into()));
         }
         let replacement = if let Some(path) = path {
-            let workspace = self.shared.workspace().ok_or_else(|| HostError::NotFound("no project open".into()))?;
-            let (root, real) = workspace
-                .projects()
-                .into_iter()
-                .filter_map(|root| ide_plugin::resolve_new_in_root(&root, &to_ipc(path)).ok().map(|real| (root, real)))
-                .max_by_key(|(root, _)| root.components().count())
-                .ok_or_else(|| HostError::Invalid("path outside open projects".into()))?;
+            // The decoration follows the file, not the window's project: editors render
+            // whatever they have open, including files outside every project root. The
+            // set's root stays the path's own (deepest open) project for tree filtering.
+            let root = self
+                .shared
+                .workspace()
+                .map(|w| {
+                    w.projects()
+                        .into_iter()
+                        .filter(|root| path.starts_with(root))
+                        .max_by_key(|root| root.components().count())
+                })
+                .unwrap_or_default()
+                .unwrap_or_else(|| path.parent().map(Path::to_path_buf).unwrap_or_else(|| path.to_path_buf()));
             Some(super::DecorationSet {
                 root: root.into(),
-                path: real.into(),
+                path: ide_core::IpcPath(path.to_path_buf()),
                 set_id: set.into(),
                 tree,
                 items,
@@ -4188,6 +4189,8 @@ fn decoration_style(style: &str) -> bool {
             | "warning"
             | "error"
             | "info"
+            | "typo"
+            | "weak"
             | "underline"
             | "strikethrough"
             | "muted"
@@ -4308,8 +4311,11 @@ mod workbench_tests {
         };
         api.decorations(Some(&path), "set", vec![item("highlight"), item("unknown")]).unwrap();
         assert_eq!(api.shared.decoration_sets()["test"][0].items.len(), 1);
-        assert!(api.decorations(Some(&root.join("../outside.txt")), "set", vec![]).is_err());
+        // Decorations follow the file: a path outside the open project is accepted too.
+        api.decorations(Some(&root.join("../outside.txt")), "set", vec![]).unwrap();
+        assert_eq!(api.shared.decoration_sets()["test"].len(), 2);
         api.decorations(None, "set", vec![]).unwrap();
+        assert!(api.shared.decoration_sets()["test"].is_empty());
         for i in 0..50 {
             api.decorations(Some(&path), &format!("s{i}"), vec![]).unwrap();
         }
@@ -4350,6 +4356,29 @@ mod workbench_tests {
         api.shared.clear_plugin("test", true);
         assert!(api.shared.decoration_sets().is_empty());
     }
+    #[test]
+    fn decoration_styles_keep_the_severity_palette_the_editor_renders() {
+        // Inspection Lens colours typos and weak warnings with their own styles; the
+        // host must keep them, not silently drop them the way an unknown style is dropped.
+        for style in [
+            "highlight",
+            "search",
+            "added",
+            "modified",
+            "removed",
+            "warning",
+            "error",
+            "info",
+            "typo",
+            "weak",
+            "underline",
+            "strikethrough",
+            "muted",
+        ] {
+            assert!(decoration_style(style), "{style} should be a known style");
+        }
+        assert!(!decoration_style("unknown"));
+    }
     fn git(root: &Path, args: &[&str]) {
         let out = StdCommand::new("git").current_dir(root).args(args).output().unwrap();
         assert!(out.status.success(), "{}", String::from_utf8_lossy(&out.stderr));

crates/ide-host/src/plugins/event_paths.rs

@@ -129,6 +129,7 @@ impl PluginHost {
                 }
                 let path = match event {
                     WorkbenchEvent::FileOpened(path) | WorkbenchEvent::FileSaved(path) => Path::new(path),
+                    WorkbenchEvent::EditorFocused(Some(path)) => Path::new(path),
                     WorkbenchEvent::DocumentChanged(change) => Path::new(&change.path),
                     _ => return Some(event.clone()),
                 };
@@ -136,16 +137,25 @@ impl PluginHost {
                     return None;
                 }
                 let workspace = workspace.as_ref()?;
+                let real = ide_plugin::resolve_real(path);
+                // The file's own project, not the invoking window's: annotations follow
+                // the file, so a plugin hears about a file another window has open.
                 let root = match client {
-                    Some(client) => workspace.project_of(client),
-                    None => {
-                        let real = ide_plugin::resolve_real(path);
-                        workspace
-                            .projects()
-                            .into_iter()
-                            .filter(|r| real.starts_with(ide_plugin::resolve_real(r)))
-                            .max_by_key(|r| r.components().count())
-                    }
+                    Some(client) => workspace
+                        .project_of(client)
+                        .filter(|r| real.starts_with(ide_plugin::resolve_real(r)))
+                        .or_else(|| {
+                            workspace
+                                .projects()
+                                .into_iter()
+                                .filter(|r| real.starts_with(ide_plugin::resolve_real(r)))
+                                .max_by_key(|r| r.components().count())
+                        }),
+                    None => workspace
+                        .projects()
+                        .into_iter()
+                        .filter(|r| real.starts_with(ide_plugin::resolve_real(r)))
+                        .max_by_key(|r| r.components().count()),
                 }?;
                 if plugin.dev_root.as_deref().is_some_and(|r| r != root) {
                     return None;

crates/ide-host/src/plugins/ui_points.rs

@@ -352,6 +352,15 @@ where
     deserializer.deserialize_map(Properties)
 }
 
+/// A sample shown in a setting's own style (the Colour Scheme colours), e.g. the
+/// message an Inspection Lens severity produces.
+#[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
+pub struct SettingExample {
+    pub text: String,
+    /// `error`, `warning`, `weak`, `typo`, `info` or `muted`: which sample style to draw.
+    pub style: String,
+}
+
 /// One setting of a plugin.
 #[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
 #[serde(rename_all = "camelCase")]
@@ -371,6 +380,8 @@ pub struct SettingSchema {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub group: Option<String>,
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub example: Option<SettingExample>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
     pub items: Option<Box<SettingSchema>>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub properties: Vec<SettingSchema>,
@@ -455,6 +466,20 @@ fn setting_at(key: &str, raw: &serde_json::value::RawValue, depth: u8) -> Result
             Some(_) => Err(format!("setting {key:?}: `{name}` is a string up to {max} bytes")),
         }
     };
+    let example = match o.get("example") {
+        None => None,
+        Some(v) => {
+            let e: SettingExample = serde_json::from_value(v.clone())
+                .map_err(|e| format!("setting {key:?}: `example` is {{\"text\", \"style\"}}: {e}"))?;
+            if e.text.is_empty() || e.text.len() > 300 {
+                return Err(format!("setting {key:?}: `example.text` is 1–300 bytes"));
+            }
+            if e.style.len() > 32 || !e.style.chars().all(|c| c.is_ascii_lowercase()) {
+                return Err(format!("setting {key:?}: `example.style` is a lowercase style name"));
+            }
+            Some(e)
+        }
+    };
     let s = SettingSchema {
         key: key.to_owned(),
         kind: kind.to_owned(),
@@ -464,6 +489,7 @@ fn setting_at(key: &str, raw: &serde_json::value::RawValue, depth: u8) -> Result
         options,
         multiline: o.get("multiline").and_then(Value::as_bool).unwrap_or(false),
         group: text("group", MAX_TITLE)?,
+        example,
         items,
         properties,
     };

crates/ide-host/src/project.rs

@@ -675,9 +675,10 @@ impl Host {
             agents.set_new_task_approvals_hook(Arc::new(move || settings.effective().agents.new_task_approvals));
         }
         let approvals = self.mcp_approvals.clone();
+        let secrets = self.agent_secrets.clone();
         let root = root.to_path_buf();
         agents.set_mcp_servers_hook(Box::new(move || {
-            crate::ops::agent::session_mcp_servers(&settings, &approvals, &root)
+            crate::ops::agent::session_mcp_servers(&settings, &approvals, &secrets, &root)
         }));
         (db, http_history, agents)
     }

crates/ide-host/tests/mcp.rs

@@ -231,7 +231,11 @@ async fn mutations_preserve_unsaved_text_and_reject_metadata_and_escapes() {
         .iter()
         .rev()
         .find_map(|event| match event {
-            IdeEvent::WorkspaceEditApplied { id, .. } => Some(*id),
+            // Undoable like a refactoring, but marked as the agent's, so it isn't announced as one.
+            IdeEvent::WorkspaceEditApplied { id, by_agent, .. } => {
+                assert!(*by_agent, "an MCP edit is the agent's");
+                Some(*id)
+            }
             _ => None,
         })
         .unwrap();

crates/ide-host/tests/mcp_secrets.rs

@@ -0,0 +1,133 @@
+//! Values of the user's MCP servers' environment variables and HTTP headers live in the
+//! credential store; `settings.toml` keeps only their names. A project's own servers keep
+//! their values in the project's file, where the project shares them.
+
+use ide_agent::{McpKeyValue, McpScope, McpServer, McpServerInput};
+use ide_core::NullSink;
+use ide_core::settings::McpTransport;
+use ide_host::{Host, HostConfig};
+use ide_ssh::secrets::testing::{files_containing, use_memory_store};
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+const VALUE: &str = "mcp-value-0f3c9a";
+
+fn host(dir: &Path) -> Arc<Host> {
+    Arc::new(Host::new(HostConfig {
+        config_dir: dir.join("config"),
+        data_dir: dir.join("data"),
+        local_data_dir: dir.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,
+    }))
+}
+
+fn project(tmp: &tempfile::TempDir) -> PathBuf {
+    let root = dunce::canonicalize(tmp.path()).unwrap().join("project");
+    std::fs::create_dir_all(root.join(".openidea")).unwrap();
+    root
+}
+
+fn open(host: &Host, root: &Path) {
+    host.trust.decide(root, true, false).unwrap();
+    host.open_project("main", root).unwrap();
+}
+
+fn header(servers: &[McpServer], id: &str) -> String {
+    let server = servers.iter().find(|s| s.id == id).unwrap_or_else(|| panic!("{id} in {servers:?}"));
+    server.headers.iter().find(|h| h.name == "Authorization").map(|h| h.value.clone()).unwrap_or_default()
+}
+
+fn input(name: &str, scope: McpScope) -> McpServerInput {
+    McpServerInput {
+        id: None,
+        name: name.into(),
+        scope,
+        transport: McpTransport::Http,
+        enabled: true,
+        command: None,
+        args: vec![],
+        env: vec![],
+        url: Some("https://mcp.example/v1".into()),
+        headers: vec![McpKeyValue { name: "Authorization".into(), value: format!("Bearer {VALUE}") }],
+        agents: vec![],
+    }
+}
+
+const SERVER_WITH_VALUE: &str = r#"
+[agents.mcpServers.remote]
+transport = "http"
+enabled = true
+url = "https://mcp.example/v1"
+headers = { Authorization = "Bearer mcp-value-0f3c9a" }
+"#;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn user_server_values_stay_out_of_the_user_settings() {
+    use_memory_store();
+    let tmp = tempfile::tempdir().unwrap();
+    let root = project(&tmp);
+    let host = host(tmp.path());
+    open(&host, &root);
+    for (name, scope) in [("user-server", McpScope::User), ("repo-server", McpScope::Workspace)] {
+        ide_host::ops::agent::mcp_save(&host, "main", input(name, scope)).unwrap();
+    }
+    host.close_project("main");
+
+    // Only the project's own file holds a value; nothing in the user's config or data does.
+    let found = files_containing(tmp.path(), VALUE);
+    assert!(found.len() == 1 && found[0].ends_with(Path::new(".openidea/settings.toml")), "{found:?}");
+
+    let host = self::host(tmp.path());
+    open(&host, &root);
+    let servers = ide_host::ops::agent::mcp_list(&host, "main").unwrap();
+    assert_eq!(header(&servers, "user::user-server"), format!("Bearer {VALUE}"));
+    assert_eq!(header(&servers, "workspace::repo-server"), format!("Bearer {VALUE}"));
+    host.close_project("main");
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn values_in_user_settings_move_to_the_credential_store() {
+    use_memory_store();
+    let tmp = tempfile::tempdir().unwrap();
+    let root = project(&tmp);
+    std::fs::create_dir_all(tmp.path().join("config")).unwrap();
+    let saved = SERVER_WITH_VALUE.replace("Authorization =", "X-Saved = \"\", Authorization =");
+    std::fs::write(tmp.path().join("config/settings.toml"), saved).unwrap();
+    ide_host::agent_secrets::AgentSecrets::new(&tmp.path().join("data"))
+        .set("mcp/user/remote/header/X-Saved", "saved-earlier")
+        .unwrap();
+    let host = host(tmp.path());
+    assert_eq!(files_containing(tmp.path(), VALUE), Vec::<PathBuf>::new());
+    open(&host, &root);
+    let servers = ide_host::ops::agent::mcp_list(&host, "main").unwrap();
+    assert_eq!(header(&servers, "user::remote"), format!("Bearer {VALUE}"));
+    let remote = servers.iter().find(|s| s.id == "user::remote").unwrap();
+    assert!(remote.headers.iter().any(|h| h.name == "X-Saved" && h.value == "saved-earlier"), "{remote:?}");
+    host.close_project("main");
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn a_projects_own_values_stay_in_its_file() {
+    use_memory_store();
+    let tmp = tempfile::tempdir().unwrap();
+    let root = project(&tmp);
+    let file = root.join(".openidea/settings.toml");
+    std::fs::write(&file, SERVER_WITH_VALUE).unwrap();
+    let host = host(tmp.path());
+    open(&host, &root);
+    let servers = ide_host::ops::agent::mcp_list(&host, "main").unwrap();
+    assert_eq!(header(&servers, "workspace::remote"), format!("Bearer {VALUE}"));
+    assert_eq!(std::fs::read_to_string(&file).unwrap(), SERVER_WITH_VALUE, "reading leaves the project file alone");
+
+    // Saving the servers keeps the project's values in the project's file for everyone else.
+    let servers = ide_host::ops::agent::mcp_set_enabled(&host, "main", "workspace::remote".into(), false).unwrap();
+    assert_eq!(header(&servers, "workspace::remote"), format!("Bearer {VALUE}"));
+    assert!(std::fs::read_to_string(&file).unwrap().contains(VALUE));
+    assert_eq!(files_containing(&tmp.path().join("data"), VALUE), Vec::<PathBuf>::new());
+    host.close_project("main");
+}

crates/ide-host/tests/plugin_diagnostics.rs

@@ -430,3 +430,61 @@ async fn typing_is_debounced_versioned_and_scoped_to_document_project_and_window
     host.shutdown().await;
     set_editor_providers(None);
 }
+
+/// A host with a project open: `problems` and `decorations` need a workspace.
+fn harness(root: &Path) -> Arc<Host> {
+    let host = Arc::new(Host::new(HostConfig {
+        config_dir: root.join("config"),
+        data_dir: root.join("data"),
+        local_data_dir: root.join("local"),
+        languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+        syntax: Arc::default(),
+        sink_for: Box::new(|_| Arc::new(ide_core::NullSink)),
+        owner: |w| w,
+        runtime: tokio::runtime::Handle::current(),
+        project_environment: false,
+    }));
+    host.open_project("main", root).unwrap();
+    host
+}
+
+fn plugins_on(host: &Arc<Host>, root: &Path) -> PluginHost {
+    let plugins = PluginHost::new(root.join("plugins"), Arc::new(|_: Option<&str>, _| {}), generous()).unwrap();
+    plugins.set_workspace(Some(Arc::new(HostWorkspace(Arc::downgrade(host)))));
+    plugins.install_from_dir(&fixture(), &Consent::all()).unwrap();
+    plugins
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn a_plugin_reads_back_the_diagnostics_the_host_recorded() {
+    let tmp = tempfile::tempdir().unwrap();
+    let host = harness(tmp.path());
+    let plugins = plugins_on(&host, tmp.path());
+    let path = tmp.path().join("a.txt");
+    std::fs::write(&path, "text").unwrap();
+    // `publish` goes through the host's recording sink into the snapshot a plugin reads.
+    let invocation = || Invocation { client: Some("main".into()), ..Invocation::default() };
+    plugins.run_command(ID, "publish", Some(path.to_str().unwrap()), invocation()).unwrap();
+    let problems = plugins.run_command(ID, "problems", None, invocation()).unwrap().unwrap();
+    assert!(problems.contains("a.txt"), "problems returned {problems:?}");
+    assert!(problems.ends_with(":1"), "one diagnostic from its producer, got {problems:?}");
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn a_line_end_annotation_takes_the_typo_and_weak_styles() {
+    let tmp = tempfile::tempdir().unwrap();
+    let host = harness(tmp.path());
+    let plugins = plugins_on(&host, tmp.path());
+    let path = tmp.path().join("a.txt");
+    std::fs::write(&path, "text").unwrap();
+    // `decorate` publishes both styles; the host drops an unknown style silently, so a
+    // rejection here means one of the two is not a known decoration style.
+    plugins
+        .run_command(
+            ID,
+            "decorate",
+            Some(path.to_str().unwrap()),
+            Invocation { client: Some("main".into()), ..Invocation::default() },
+        )
+        .unwrap();
+}

crates/ide-host/tests/plugin_workbench.rs

@@ -139,7 +139,7 @@ async fn text_search_uses_overlay_excludes_utf16_and_limits() {
 }
 
 #[tokio::test(flavor = "multi_thread")]
-async fn problems_share_project_reports_and_keep_sources_separate() {
+async fn problems_come_from_the_host_snapshot_whatever_window_published_them() {
     let f = Harness::new();
     let path = f.root.join("a.txt");
     std::fs::write(&path, "text").unwrap();
@@ -153,21 +153,30 @@ async fn problems_share_project_reports_and_keep_sources_separate() {
         deprecated: false,
         server: None,
     };
-    f.host.mcp_reports.report_problems(
-        "second",
-        true,
-        vec![ide_host::mcp::FileProblems {
+    // Producers publish per (file, producer) through the event sink, like the
+    // language servers and the spelling check do.
+    let publish = |host: &Host, source: &str, items: Vec<Diagnostic>| {
+        host.project("main").unwrap().sink.emit(ide_core::IdeEvent::Diagnostics {
             path: path.clone().into(),
-            items: vec![diagnostic("lsp"), diagnostic("plugin")],
-        }],
-    );
+            source: source.into(),
+            items,
+        });
+    };
+    publish(&f.host, "rust-analyzer", vec![diagnostic("lsp")]);
+    publish(&f.host, "build", vec![diagnostic("plugin")]);
+    // A file outside the window's project is visible too: annotations follow the file.
+    let outside = f.host.diagnostics.problems().len();
     let workspace = f.workspace();
     let files = workspace.problems("main", Some(&path)).unwrap();
     assert_eq!(files.len(), 2);
     assert!(files.iter().all(|f| f.diagnostics.len() == 1));
     assert!(workspace.problems("main", Some(&f.root.join("other.txt"))).unwrap().is_empty());
-    f.host.mcp_reports.forget_window("second");
-    assert!(workspace.problems("main", None).unwrap().is_empty());
+    assert_eq!(outside, 2);
+    // A full replacement per producer clears only that producer.
+    publish(&f.host, "rust-analyzer", vec![]);
+    let files = workspace.problems("main", None).unwrap();
+    assert_eq!(files.len(), 1);
+    assert_eq!(files[0].source, "build");
 }
 
 #[tokio::test(flavor = "multi_thread")]

crates/ide-host/tests/plugins.rs

@@ -2554,7 +2554,8 @@ fn official_git_toolbox_fetches_on_schedule_after_idle_reclaim() {
     f.install(&official("git-toolbox"));
     // Focusing an editor wakes it to show the branch (nothing fetched yet).
     let now = Instant::now();
-    f.host.post_events(Some("main"), vec![WorkbenchEvent::EditorFocused(Some("src/notes.txt".into()))]);
+    let focused = f.project.join("src/notes.txt").to_string_lossy().into_owned();
+    f.host.post_events(Some("main"), vec![WorkbenchEvent::EditorFocused(Some(focused))]);
     f.host.flush_events_at(now + Duration::from_secs(3));
     assert!(f.host.wait_events(Duration::from_secs(10)));
     let item = |host: &PluginHost| {
@@ -2609,6 +2610,82 @@ fn git_toolbox_does_not_fetch_untrusted_projects() {
     assert!(err.contains("Restricted Mode"), "{err}");
 }
 
+/// Git Toolbox in a workspace window whose container folder is not a
+/// repository (every member is its own clone): the status bar follows the
+/// focused file's repository, and the scheduled fetch covers every member.
+#[test]
+fn official_git_toolbox_follows_members_in_a_workspace() {
+    let f = fixture(Limits { idle_timeout: Some(Duration::from_millis(50)), ..Limits::default() });
+    let tmp = tempfile::tempdir().unwrap();
+    // A remote with `main`, cloned by member `a` (at `main`) and member `b`
+    // (on its own branch, to tell the two apart in the status bar).
+    let remote = tmp.path().join("remote.git");
+    std::fs::create_dir(&remote).unwrap();
+    git(&remote, &["init", "--bare", "-b", "main"]);
+    let seed = tmp.path().join("seed");
+    std::fs::create_dir(&seed).unwrap();
+    git(&seed, &["init", "-b", "main"]);
+    std::fs::write(seed.join("seed.txt"), "seed\n").unwrap();
+    git(&seed, &["add", "."]);
+    git(&seed, &["commit", "-m", "one"]);
+    git(&seed, &["remote", "add", "origin", remote.to_str().unwrap()]);
+    git(&seed, &["push", "-u", "origin", "main"]);
+    let member_a = tmp.path().join("member-a");
+    git(tmp.path(), &["clone", remote.to_str().unwrap(), member_a.to_str().unwrap()]);
+    let member_a = dunce::canonicalize(member_a).unwrap();
+    let member_b = tmp.path().join("member-b");
+    git(tmp.path(), &["clone", remote.to_str().unwrap(), member_b.to_str().unwrap()]);
+    let member_b = dunce::canonicalize(member_b).unwrap();
+    git(&member_b, &["checkout", "-b", "feature"]);
+    git(&member_b, &["push", "-u", "origin", "feature"]);
+    // The window's project is the container; the members are attached to it.
+    f.workspace.other_roots.lock().extend([member_a.clone(), member_b.clone()]);
+
+    f.install(&official("git-toolbox"));
+    let item = |host: &PluginHost| {
+        host.status_items().into_iter().find(|(p, id, _)| p == "openidea.git-toolbox" && id == "branch")
+    };
+    let now = Instant::now();
+    let focus = |path: &Path| {
+        f.host
+            .post_events(Some("main"), vec![WorkbenchEvent::EditorFocused(Some(path.to_string_lossy().into_owned()))]);
+        f.host.flush_events_at(now + Duration::from_secs(3));
+        f.host.wait_events(Duration::from_secs(10));
+    };
+    // Focusing a file of member `a` shows that member's branch: the window's
+    // project is the container, which is no repository.
+    focus(&member_a.join("seed.txt"));
+    assert_eq!(item(&f.host).map(|(_, _, i)| i.text), Some("main".into()));
+    // Fetch Now fetches the shown member; the container is not a repository.
+    f.run("openidea.git-toolbox", "fetch", None).unwrap();
+    let fetched = stored(&f, "openidea.git-toolbox");
+    assert!(
+        fetched.iter().any(|(key, _)| key == &format!("last-fetch:{}", to_ipc(&member_a))),
+        "{member_a:?}: {fetched:?}"
+    );
+    assert_eq!(fetched.iter().filter(|(key, _)| key.starts_with("last-fetch:")).count(), 1, "{fetched:?}");
+    // Switching to the other member follows it.
+    focus(&member_b.join("seed.txt"));
+    assert_eq!(item(&f.host).map(|(_, _, i)| i.text), Some("feature".into()));
+
+    // Idle: reclaimed; the schedule then wakes it to fetch every member (the
+    // container is skipped: it has no repository).
+    std::thread::sleep(Duration::from_millis(100));
+    f.host.tick();
+    assert_eq!(item(&f.host).map(|(_, _, i)| i.text), Some("feature".into()), "the item stays while it sleeps");
+    f.take_events();
+    f.host.tick_at(Instant::now() + Duration::from_secs(301));
+    assert!(f.host.wait_events(Duration::from_secs(30)));
+    let fetched = stored(&f, "openidea.git-toolbox");
+    for member in [&member_a, &member_b] {
+        assert!(
+            fetched.iter().any(|(key, _)| key == &format!("last-fetch:{}", to_ipc(member))),
+            "{member:?}: {fetched:?}"
+        );
+    }
+    assert_eq!(item(&f.host).map(|(_, _, i)| i.text), Some("feature".into()));
+}
+
 /// A tiny HTTP server: each request is answered after `delay(n)` (n counts
 /// requests) with `body`. Returns its port and the request bodies it got.
 fn http_server(
@@ -2916,13 +2993,18 @@ fn official_csv_editor_edits_the_shared_document() {
     f.host.view_event("openidea.csv-editor", "table", cell, inv.clone()).unwrap();
     assert_eq!(f.workspace.text("people.csv"), "name,city\nAda,\"Paris, FR\"\nBob,Oslo\n");
 
+    // Add Row appends, also on wasm32 (where its row index used to wrap to the header).
+    let add = ide_plugin::ViewEvent::Button { id: "add-row".into() };
+    f.host.view_event("openidea.csv-editor", "table", add, inv.clone()).unwrap();
+    assert_eq!(f.workspace.text("people.csv"), "name,city\nAda,\"Paris, FR\"\nBob,Oslo\n,\n");
+
     // Settings: without a header row every record is a row.
     let mut values = serde_json::Map::new();
     values.insert("firstRowIsHeader".into(), serde_json::Value::Bool(false));
     f.workspace.settings.lock().insert("openidea.csv-editor".into(), values);
     let view = f.host.render_view("openidea.csv-editor", "table", None, inv.clone()).unwrap();
     let ide_plugin::ViewBody::Table(t) = &view.body else { panic!("{view:?}") };
-    assert_eq!((t.columns[0].as_str(), t.total_rows), ("Column 1", 3));
+    assert_eq!((t.columns[0].as_str(), t.total_rows), ("Column 1", 4));
 
     // Undeclared views are refused before any code runs.
     let err = f.host.render_view("openidea.csv-editor", "other", None, inv).unwrap_err();

crates/ide-host/tests/project_smoke.rs

@@ -252,6 +252,77 @@ async fn maven_sync() {
     assert!(!junit.children.is_empty(), "{junit:?}");
 }
 
+/// The launch classpath must come from the runner JDK, not the JDK that happened
+/// to load the language-server model: JDK-activated profiles can select a
+/// different dependency classifier. Use real Maven so this covers the scenario
+/// rather than only the probe arguments.
+#[test]
+#[ignore = "project smoke: needs Maven and a JDK"]
+fn maven_launch_classpath_uses_the_runner_jdk_classifier() {
+    let tmp = tempfile::tempdir().unwrap();
+    let root = tmp.path();
+    let java_home = PathBuf::from(std::env::var("JAVA_HOME").expect("JAVA_HOME"));
+    let release = std::fs::read_to_string(java_home.join("release")).unwrap();
+    let version = release
+        .lines()
+        .find_map(|line| line.strip_prefix("JAVA_VERSION=\""))
+        .and_then(|line| line.strip_suffix('"'))
+        .expect("JAVA_VERSION in release");
+    let major = version.strip_prefix("1.").unwrap_or(version).split(['.', '_']).next().unwrap().parse::<u32>().unwrap();
+    let jar = java_home.join(if cfg!(windows) { "bin/jar.exe" } else { "bin/jar" });
+    let jars = root.join("libs");
+    let staging = root.join("empty");
+    std::fs::create_dir_all(&jars).unwrap();
+    std::fs::create_dir_all(&staging).unwrap();
+    for name in ["api-jdk8.jar", "api-jdk9.jar"] {
+        let status = std::process::Command::new(&jar)
+            .args(["cf"])
+            .arg(jars.join(name))
+            .arg(".")
+            .current_dir(&staging)
+            .status()
+            .unwrap();
+        assert!(status.success());
+    }
+    std::fs::write(
+        root.join("pom.xml"),
+        r#"<project xmlns="http://maven.apache.org/POM/4.0.0">
+          <modelVersion>4.0.0</modelVersion>
+          <groupId>demo</groupId><artifactId>jdk-classifier</artifactId><version>1</version>
+          <profiles>
+            <profile><id>jdk8</id><activation><jdk>1.8</jdk></activation><dependencies>
+              <dependency><groupId>demo</groupId><artifactId>api</artifactId><version>1</version><classifier>jdk8</classifier>
+                <scope>system</scope><systemPath>${project.basedir}/libs/api-jdk8.jar</systemPath></dependency>
+            </dependencies></profile>
+            <profile><id>jdk9</id><activation><jdk>[9,)</jdk></activation><dependencies>
+              <dependency><groupId>demo</groupId><artifactId>api</artifactId><version>1</version><classifier>jdk9</classifier>
+                <scope>system</scope><systemPath>${project.basedir}/libs/api-jdk9.jar</systemPath></dependency>
+            </dependencies></profile>
+          </profiles>
+        </project>"#,
+    )
+    .unwrap();
+    let cache = root.join("cache");
+    let mut model = ide_build::load(root, &cache, None);
+    for project in &mut model.maven.as_mut().unwrap().projects {
+        project.env.insert("JAVA_HOME".into(), java_home.to_string_lossy().into_owned());
+    }
+    let classpath = ide_build::compile::module_classpath(
+        root,
+        &model,
+        root,
+        false,
+        None,
+        &root.join("classpath-cache"),
+        &ide_core::CancellationToken::new(),
+    )
+    .unwrap();
+    let expected = if major <= 8 { "api-jdk8.jar" } else { "api-jdk9.jar" };
+    let other = if major <= 8 { "api-jdk9.jar" } else { "api-jdk8.jar" };
+    assert!(classpath.contains(expected), "{classpath}");
+    assert!(!classpath.contains(other), "{classpath}");
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 #[ignore = "project smoke: needs Gradle and a JDK"]
 async fn gradle_sync() {

crates/ide-host/tests/trust.rs

@@ -183,7 +183,7 @@ async fn welcome_window_browses_selected_ssh_host_without_executing_commands() {
     host.remote.test_connection(&connection, "/projects").await.unwrap();
     let local = tmp.path().join("local-deployment");
     std::fs::create_dir(&local).unwrap();
-    ide_host::ops::deploy::deploy_test_connection(&host, FsConnection::Local, local.to_str().unwrap().into())
+    ide_host::ops::deploy::deploy_test_connection(&host, FsConnection::Local, local.to_str().unwrap().into(), None)
         .await
         .unwrap();
     assert_eq!(std::fs::read_dir(local).unwrap().count(), 0, "write probe is cleaned up");

crates/ide-index/src/data.rs

@@ -1,4 +1,13 @@
-//! In-memory index: one slot per file, symbols stored with their file.
+//! In-memory index: one slot per file, with compact query-time tables derived from it.
+//!
+//! Queries never walk the fat `FileEntry` structs: `HotFiles`, `HotDirs` and `SymTable` hold
+//! only the fields a scan needs, packed in dense rows with interned strings, so a query
+//! streams contiguous memory instead of chasing `Box<[Sym]>` / `Box<str>` pointers.
+//! They are plain data, updated eagerly by `insert`/`remove` (every mutation needs `&mut
+//! IndexData`), and all queries run under the `IndexData` read lock: a scan therefore sees
+//! one consistent snapshot, and the only "invalidation" is the update itself. Space left
+//! behind by replaced/removed entries is reclaimed by compaction inside `insert`/`remove`
+//! once it dominates the table, and by `shrink`.
 
 use ide_core::{Range, SymbolKind};
 use serde::{Deserialize, Serialize};
@@ -33,6 +42,40 @@ pub(crate) fn mask_bit(b: u8) -> u64 {
     }
 }
 
+/// A substring of an interned text arena.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub(crate) struct Span {
+    pub start: u32,
+    pub len: u32,
+}
+
+impl Span {
+    /// A slice of nothing; used for optional fields (`None` containers).
+    pub(crate) const NONE: Span = Span { start: u32::MAX, len: 0 };
+
+    /// Appends `s` to `arena`, returning the span it will occupy.
+    ///
+    /// Spans are `u32`-addressed and `NONE` uses `u32::MAX` as its start, so an
+    /// arena that reaches that bound cannot be represented. Fail loudly here
+    /// instead of truncating the offsets: a wrapped span would make [`Self::get`]
+    /// slice unrelated text, or panic far from the actual cause.
+    #[inline]
+    fn of(arena: &str, s: &str) -> Self {
+        let start = u32::try_from(arena.len()).expect("index text arena exceeded the 4 GiB span limit");
+        let len = u32::try_from(s.len()).expect("index text span exceeded the 4 GiB span limit");
+        assert!(
+            start != u32::MAX && start.checked_add(len).is_some(),
+            "index text arena exceeded the 4 GiB span limit"
+        );
+        Self { start, len }
+    }
+
+    #[inline]
+    pub(crate) fn get(self, arena: &str) -> &str {
+        &arena[self.start as usize..(self.start + self.len) as usize]
+    }
+}
+
 /// Persisted per-file record (postcard in redb, keyed by the relative path).
 #[derive(Clone, Debug, Default, Serialize, Deserialize)]
 pub(crate) struct FileRecord {
@@ -52,12 +95,12 @@ pub(crate) struct StoredSymbol {
     pub range: Range,
 }
 
-pub(crate) struct Sym {
-    pub name: Box<str>,
+/// A symbol resolved out of [`SymTable`].
+pub(crate) struct SymRef<'a> {
+    pub name: &'a str,
     pub kind: SymbolKind,
-    pub container: Option<Box<str>>,
+    pub container: Option<&'a str>,
     pub range: Range,
-    pub mask: u64,
 }
 
 pub(crate) struct FileEntry {
@@ -73,38 +116,34 @@ pub(crate) struct FileEntry {
     pub mtime: u64,
     pub size: u64,
     pub hash: [u8; 32],
-    pub symbols: Box<[Sym]>,
+    /// Range of this file's symbols in [`IndexData::syms`].
+    pub sym_start: u32,
+    pub sym_len: u32,
     pub ignored: bool,
 }
 
 impl FileEntry {
-    pub(crate) fn new(path: PathBuf, rel: String, record: FileRecord) -> Self {
+    /// Splits the record into the entry and its symbols; the symbols are flattened into
+    /// the index-wide [`SymTable`] by [`IndexData::insert`].
+    pub(crate) fn new(path: PathBuf, rel: String, record: FileRecord) -> (Self, Vec<StoredSymbol>) {
         let name_start = rel.rfind('/').map_or(0, |i| i + 1);
         let name = &rel[name_start..];
-        let symbols = record
-            .symbols
-            .into_iter()
-            .map(|s| Sym {
-                mask: char_mask(&s.name),
-                name: s.name.into_boxed_str(),
-                kind: s.kind,
-                container: s.container.map(String::into_boxed_str),
-                range: s.range,
-            })
-            .collect();
-        Self {
+        let FileRecord { mtime, size, hash, symbols, ignored } = record;
+        let entry = Self {
             name_start_chars: rel[..name_start].chars().count() as u32,
             name_mask: char_mask(name),
             rel_mask: char_mask(&rel),
             name_start: name_start as u32,
             path,
             rel: rel.into_boxed_str(),
-            mtime: record.mtime,
-            size: record.size,
-            hash: record.hash,
-            symbols,
-            ignored: record.ignored,
-        }
+            mtime,
+            size,
+            hash,
+            sym_start: 0,
+            sym_len: 0,
+            ignored,
+        };
+        (entry, symbols)
     }
 
     pub(crate) fn name(&self) -> &str {
@@ -115,38 +154,391 @@ impl FileEntry {
         &self.rel[..self.name_start as usize]
     }
 
-    pub(crate) fn record(&self) -> FileRecord {
-        FileRecord {
-            mtime: self.mtime,
-            size: self.size,
-            hash: self.hash,
-            symbols: self
-                .symbols
-                .iter()
-                .map(|s| StoredSymbol {
-                    name: s.name.to_string(),
-                    kind: s.kind,
-                    container: s.container.as_deref().map(str::to_owned),
-                    range: s.range,
-                })
-                .collect(),
-            ignored: self.ignored,
-        }
-    }
-
     /// Whether the entry is out of date for `found` on disk.
     pub(crate) fn stale_for(&self, found: &crate::filter::Found) -> bool {
         self.mtime != found.mtime || self.size != found.size || self.ignored != found.ignored
     }
 }
 
+/// The hot fields of one file slot, packed for the query scan; no pointers.
+pub(crate) struct FileRow {
+    /// `rel` in [`HotFiles`]' arena.
+    pub rel: Span,
+    /// Byte offset of the file name inside `rel`.
+    pub name_start: u32,
+    pub sym_start: u32,
+    pub sym_len: u32,
+    /// Union of every symbol's [`char_mask`]: a selective symbol query can skip
+    /// the whole file before touching its symbol range.
+    pub sym_mask: u64,
+    pub rel_mask: u64,
+    pub name_mask: u64,
+    /// Mask of the directory part (`rel[..name_start]`), precomputed for path queries.
+    pub dir_mask: u64,
+    /// `rel` is pure ASCII, so nucleo can match it without a UTF-32 conversion.
+    pub ascii: bool,
+    /// The slot holds a file; free slots keep a row so scans line up with `IndexData::files`.
+    pub live: bool,
+}
+
+impl FileRow {
+    #[inline]
+    pub(crate) fn rel<'a>(&self, arena: &'a str) -> &'a str {
+        self.rel.get(arena)
+    }
+
+    #[inline]
+    pub(crate) fn name<'a>(&self, arena: &'a str) -> &'a str {
+        &self.rel.get(arena)[self.name_start as usize..]
+    }
+
+    #[inline]
+    pub(crate) fn dir<'a>(&self, arena: &'a str) -> &'a str {
+        &self.rel.get(arena)[..self.name_start as usize]
+    }
+}
+
+/// One dense row per file slot (same order and length as `IndexData::files`) plus the
+/// text arena the rows point into.
+#[derive(Default)]
+pub(crate) struct HotFiles {
+    pub rows: Vec<FileRow>,
+    text: String,
+    dead_text: usize,
+}
+
+impl HotFiles {
+    #[inline]
+    pub(crate) fn text(&self) -> &str {
+        &self.text
+    }
+
+    #[inline]
+    pub(crate) fn row(&self, slot: usize) -> Option<&FileRow> {
+        self.rows.get(slot).filter(|row| row.live)
+    }
+
+    #[inline]
+    pub(crate) fn row_of_slot(&self, slot: u32) -> Option<&FileRow> {
+        self.row(slot as usize)
+    }
+
+    /// `rel` of a live slot; candidate slots always are.
+    #[inline]
+    pub(crate) fn rel(&self, slot: u32) -> &str {
+        self.rows[slot as usize].rel(&self.text)
+    }
+
+    fn set(&mut self, slot: u32, row: FileRow) {
+        if self.rows.len() as u32 == slot {
+            self.rows.push(row);
+        } else {
+            self.rows[slot as usize] = row;
+        }
+    }
+
+    fn append(&mut self, rel: &str) -> Span {
+        let span = Span::of(&self.text, rel);
+        self.text.push_str(rel);
+        span
+    }
+
+    /// Updates the row of an existing slot (replace) in place.
+    fn update(&mut self, slot: u32, e: &FileEntry, sym_mask: u64) {
+        let idx = slot as usize;
+        if self.rows[idx].rel.get(&self.text) != &*e.rel {
+            self.dead_text += self.rows[idx].rel.len as usize;
+            let span = self.append(&e.rel);
+            self.rows[idx].rel = span;
+            self.rows[idx].ascii = e.rel.is_ascii();
+            self.rows[idx].dir_mask = char_mask(e.dir());
+        }
+        let row = &mut self.rows[idx];
+        row.name_start = e.name_start;
+        row.name_mask = e.name_mask;
+        row.rel_mask = e.rel_mask;
+        row.sym_start = e.sym_start;
+        row.sym_len = e.sym_len;
+        row.sym_mask = sym_mask;
+        row.live = true;
+    }
+
+    fn remove(&mut self, slot: u32) {
+        let row = &mut self.rows[slot as usize];
+        self.dead_text += row.rel.len as usize;
+        row.rel = Span::NONE;
+        row.sym_start = 0;
+        row.sym_len = 0;
+        row.sym_mask = 0;
+        row.live = false;
+    }
+
+    fn compact(&mut self) {
+        let mut text = String::with_capacity(self.text.len() - self.dead_text);
+        for row in &mut self.rows {
+            if !row.live {
+                continue;
+            }
+            let rel = row.rel.get(&self.text);
+            row.rel = Span::of(&text, rel);
+            text.push_str(rel);
+        }
+        self.text = text;
+        self.dead_text = 0;
+    }
+
+    fn shrink(&mut self) {
+        self.compact();
+        self.rows.shrink_to_fit();
+        self.text.shrink_to_fit();
+    }
+}
+
+/// One folder holding indexed files, packed for the query scan.
+pub(crate) struct DirRow {
+    /// `rel` in [`HotDirs`]' arena, including the trailing `/`.
+    pub rel: Span,
+    /// Byte offset of the last path segment inside the trimmed `rel`.
+    pub name_start: u32,
+    pub name_mask: u64,
+    /// Mask of `rel` without the trailing `/`.
+    pub rel_mask: u64,
+    pub path: PathBuf,
+}
+
+impl DirRow {
+    #[inline]
+    pub(crate) fn rel<'a>(&self, arena: &'a str) -> &'a str {
+        self.rel.get(arena)
+    }
+}
+
+#[derive(Default)]
+pub(crate) struct HotDirs {
+    pub rows: Vec<DirRow>,
+    text: String,
+    dead: usize,
+}
+
+impl HotDirs {
+    #[inline]
+    pub(crate) fn text(&self) -> &str {
+        &self.text
+    }
+
+    fn push(&mut self, rel: &str, abs: &Path) -> u32 {
+        let span = Span::of(&self.text, rel);
+        self.text.push_str(rel);
+        let trimmed = &rel[..rel.len() - 1];
+        let name_start = trimmed.rfind('/').map_or(0, |i| i + 1);
+        self.rows.push(DirRow {
+            rel: span,
+            name_start: name_start as u32,
+            name_mask: char_mask(&trimmed[name_start..]),
+            rel_mask: char_mask(trimmed),
+            path: abs.to_owned(),
+        });
+        (self.rows.len() - 1) as u32
+    }
+
+    fn remove(&mut self, row: u32, dirs: &mut HashMap<Box<str>, (PathBuf, u32, u32)>) {
+        let idx = row as usize;
+        let last = self.rows.len() - 1;
+        self.dead += self.rows[idx].rel.len as usize;
+        self.rows.swap_remove(idx);
+        if idx != last {
+            let moved = self.rows[idx].rel.get(&self.text);
+            if let Some(dir) = dirs.get_mut(moved) {
+                dir.2 = idx as u32;
+            }
+        }
+    }
+
+    fn compact(&mut self) {
+        let mut text = String::with_capacity(self.text.len() - self.dead);
+        for row in &mut self.rows {
+            let rel = row.rel.get(&self.text);
+            row.rel = Span::of(&text, rel);
+            text.push_str(rel);
+        }
+        self.text = text;
+        self.dead = 0;
+    }
+
+    fn shrink(&mut self) {
+        self.compact();
+        self.rows.shrink_to_fit();
+        self.text.shrink_to_fit();
+    }
+}
+
+/// The scan-relevant fields of one symbol: its character mask and the name in the
+/// arena. Interleaved so a scan touches one cache line per candidate instead of three
+/// parallel arrays.
+#[derive(Clone, Copy)]
+pub(crate) struct SymHead {
+    pub mask: u64,
+    pub name: Span,
+}
+
+/// Index-wide symbol storage: one row per symbol in parallel arrays, with names and
+/// containers interned in a single arena. Each file points at a contiguous range.
+#[derive(Default)]
+pub(crate) struct SymTable {
+    head: Vec<SymHead>,
+    container: Vec<Span>,
+    kind: Vec<SymbolKind>,
+    range: Vec<Range>,
+    text: String,
+    dead_rows: usize,
+}
+
+impl SymTable {
+    #[inline]
+    pub(crate) fn name(&self, i: u32) -> &str {
+        self.head[i as usize].name.get(&self.text)
+    }
+
+    #[inline]
+    pub(crate) fn mask(&self, i: u32) -> u64 {
+        self.head[i as usize].mask
+    }
+
+    #[inline]
+    pub(crate) fn container(&self, i: u32) -> Option<&str> {
+        let span = self.container[i as usize];
+        (span.start != u32::MAX).then(|| span.get(&self.text))
+    }
+
+    /// The mask + name rows of a file's contiguous symbol range.
+    #[inline]
+    pub(crate) fn heads(&self, start: u32, len: u32) -> &[SymHead] {
+        let (start, end) = (start as usize, start as usize + len as usize);
+        &self.head[start..end]
+    }
+
+    #[inline]
+    pub(crate) fn kind(&self, i: u32) -> SymbolKind {
+        self.kind[i as usize]
+    }
+
+    #[inline]
+    pub(crate) fn range(&self, i: u32) -> Range {
+        self.range[i as usize]
+    }
+
+    fn intern(&mut self, s: &str) -> Span {
+        let span = Span::of(&self.text, s);
+        self.text.push_str(s);
+        span
+    }
+
+    /// Appends a file's symbols; they stay contiguous. Returns the start index
+    /// and the union of their masks.
+    fn push(&mut self, symbols: &[StoredSymbol]) -> (u32, u64) {
+        let start = self.head.len() as u32;
+        let mut agg_mask = 0u64;
+        for s in symbols {
+            let mask = char_mask(&s.name);
+            agg_mask |= mask;
+            let name = self.intern(&s.name);
+            let container = match &s.container {
+                Some(c) => self.intern(c),
+                None => Span::NONE,
+            };
+            self.head.push(SymHead { mask, name });
+            self.container.push(container);
+            self.kind.push(s.kind);
+            self.range.push(s.range);
+        }
+        (start, agg_mask)
+    }
+
+    /// Whether `symbols` would flatten to exactly the range at `start`.
+    fn same(&self, start: u32, len: u32, symbols: &[StoredSymbol]) -> bool {
+        len as usize == symbols.len()
+            && symbols.iter().enumerate().all(|(k, s)| {
+                let i = start + k as u32;
+                self.name(i) == s.name
+                    && self.container(i) == s.container.as_deref()
+                    && self.kind(i) == s.kind
+                    && self.range(i) == s.range
+            })
+    }
+
+    fn free(&mut self, _start: u32, len: u32) {
+        self.dead_rows += len as usize;
+    }
+
+    /// Rewrites the live rows in file order, reclaiming the space of replaced files.
+    /// `files` entries keep their range in sync; queries read rows, but persistence
+    /// and `FileEntry` accessors go through the entry.
+    fn compact(&mut self, rows: &mut [FileRow], files: &mut [Option<FileEntry>]) {
+        let mut text = String::with_capacity(self.text.len());
+        let mut head = Vec::with_capacity(self.head.len() - self.dead_rows);
+        let mut container = Vec::with_capacity(head.capacity());
+        let mut kind = Vec::with_capacity(head.capacity());
+        let mut range = Vec::with_capacity(head.capacity());
+        let mut live = 0u32;
+        for (slot, row) in rows.iter_mut().enumerate() {
+            if !row.live {
+                row.sym_start = 0;
+                continue;
+            }
+            let (start, end) = (row.sym_start, row.sym_start + row.sym_len);
+            row.sym_start = live;
+            if let Some(e) = files.get_mut(slot).and_then(Option::as_mut) {
+                e.sym_start = live;
+            }
+            for i in start..end {
+                let name_span = self.head[i as usize].name;
+                let name = name_span.get(&self.text);
+                head.push(SymHead { mask: self.head[i as usize].mask, name: Span::of(&text, name) });
+                text.push_str(name);
+                let container_span = self.container[i as usize];
+                if container_span.start == u32::MAX {
+                    container.push(Span::NONE);
+                } else {
+                    let c = container_span.get(&self.text);
+                    container.push(Span::of(&text, c));
+                    text.push_str(c);
+                }
+                kind.push(self.kind[i as usize]);
+                range.push(self.range[i as usize]);
+                live += 1;
+            }
+        }
+        self.head = head;
+        self.container = container;
+        self.kind = kind;
+        self.range = range;
+        self.text = text;
+        self.dead_rows = 0;
+    }
+
+    fn shrink(&mut self) {
+        self.head.shrink_to_fit();
+        self.container.shrink_to_fit();
+        self.kind.shrink_to_fit();
+        self.range.shrink_to_fit();
+        self.text.shrink_to_fit();
+    }
+}
+
 #[derive(Default)]
 pub(crate) struct IndexData {
     pub files: Vec<Option<FileEntry>>,
     by_path: HashMap<PathBuf, u32>,
     /// Every folder holding an indexed file at any depth, keyed by its `rel` with a
-    /// trailing `/`: its absolute path and the number of files below it.
-    pub dirs: HashMap<Box<str>, (PathBuf, u32)>,
+    /// trailing `/`: its absolute path, the number of files below it, and its row in
+    /// [`HotDirs`].
+    pub dirs: HashMap<Box<str>, (PathBuf, u32, u32)>,
+    /// Compact query-time view of `files`, kept in sync by `insert`/`remove`.
+    pub hot: HotFiles,
+    /// Compact query-time view of `dirs`, kept in sync by `insert`/`remove`.
+    pub dirs_hot: HotDirs,
+    /// Flattened symbols of every file, kept in sync by `insert`/`remove`.
+    pub syms: SymTable,
     free: Vec<u32>,
     pub file_count: u32,
     pub symbol_count: u32,
@@ -161,49 +553,124 @@ impl IndexData {
         self.by_path.get(path).copied()
     }
 
-    pub(crate) fn insert(&mut self, entry: FileEntry) {
-        let symbols = entry.symbols.len() as u32;
+    /// The persisted form of a file, rebuilt from [`IndexData::syms`].
+    pub(crate) fn record(&self, e: &FileEntry) -> FileRecord {
+        FileRecord {
+            mtime: e.mtime,
+            size: e.size,
+            hash: e.hash,
+            symbols: self
+                .symbols_of(e)
+                .map(|s| StoredSymbol {
+                    name: s.name.to_owned(),
+                    kind: s.kind,
+                    container: s.container.map(str::to_owned),
+                    range: s.range,
+                })
+                .collect(),
+            ignored: e.ignored,
+        }
+    }
+
+    pub(crate) fn record_of(&self, path: &Path) -> Option<FileRecord> {
+        self.get(path).map(|e| self.record(e))
+    }
+
+    /// The symbols of one file, in declaration order.
+    pub(crate) fn symbols_of<'a>(&'a self, e: &'a FileEntry) -> impl Iterator<Item = SymRef<'a>> + 'a {
+        let syms = &self.syms;
+        (e.sym_start..e.sym_start + e.sym_len).map(move |i| SymRef {
+            name: syms.name(i),
+            kind: syms.kind(i),
+            container: syms.container(i),
+            range: syms.range(i),
+        })
+    }
+
+    pub(crate) fn insert(&mut self, mut entry: FileEntry, symbols: Vec<StoredSymbol>) {
+        let sym_len = symbols.len() as u32;
         if let Some(&slot) = self.by_path.get(&entry.path) {
-            let old = self.files[slot as usize].replace(entry);
-            self.symbol_count -= old.map_or(0, |o| o.symbols.len() as u32);
-            self.symbol_count += symbols;
+            let old = self.files[slot as usize].as_ref().expect("indexed slots are live");
+            let old_len = old.sym_len;
+            // Rescans and saves that re-parse to the same symbols reuse the range; a
+            // same-path replacement then costs nothing in the symbol table.
+            let (sym_start, sym_mask) = if self.syms.same(old.sym_start, old_len, &symbols) {
+                (old.sym_start, self.hot.rows[slot as usize].sym_mask)
+            } else {
+                self.syms.free(old.sym_start, old_len);
+                self.syms.push(&symbols)
+            };
+            entry.sym_start = sym_start;
+            entry.sym_len = sym_len;
+            self.symbol_count = self.symbol_count - old_len + sym_len;
+            self.hot.update(slot, &entry, sym_mask);
+            self.files[slot as usize] = Some(entry);
+            self.compact_if_needed();
             return;
         }
+        let (sym_start, sym_mask) = self.syms.push(&symbols);
+        entry.sym_start = sym_start;
+        entry.sym_len = sym_len;
         let slot = match self.free.pop() {
-            Some(slot) => {
-                self.files[slot as usize] = Some(entry);
-                slot
-            }
+            Some(slot) => slot,
             None => {
-                self.files.push(Some(entry));
+                self.files.push(None);
                 (self.files.len() - 1) as u32
             }
         };
-        let path = self.files[slot as usize].as_ref().map(|e| e.path.clone()).unwrap_or_default();
+        let path = entry.path.clone();
+        let (name_start, name_mask, rel_mask) = (entry.name_start, entry.name_mask, entry.rel_mask);
+        let rel = self.hot.append(&entry.rel);
+        self.hot.set(
+            slot,
+            FileRow {
+                rel,
+                name_start,
+                sym_start: entry.sym_start,
+                sym_len,
+                sym_mask,
+                rel_mask,
+                name_mask,
+                dir_mask: char_mask(&entry.rel[..name_start as usize]),
+                ascii: entry.rel.is_ascii(),
+                live: true,
+            },
+        );
+        self.files[slot as usize] = Some(entry);
         if let Some(e) = &self.files[slot as usize] {
             for (rel, abs) in ancestors(e) {
-                self.dirs.entry(rel.into()).or_insert_with(|| (abs.to_owned(), 0)).1 += 1;
+                if let Some(dir) = self.dirs.get_mut(rel) {
+                    dir.1 += 1;
+                } else {
+                    let row = self.dirs_hot.push(rel, abs);
+                    self.dirs.insert(rel.into(), (abs.to_owned(), 1, row));
+                }
             }
         }
         self.by_path.insert(path, slot);
         self.file_count += 1;
-        self.symbol_count += symbols;
+        self.symbol_count += sym_len;
+        self.compact_if_needed();
     }
 
     pub(crate) fn remove(&mut self, path: &Path) -> Option<FileEntry> {
         let slot = self.by_path.remove(path)?;
         let old = self.files[slot as usize].take()?;
         self.free.push(slot);
+        self.hot.remove(slot);
+        self.syms.free(old.sym_start, old.sym_len);
         for (rel, _) in ancestors(&old) {
-            if let Some(d) = self.dirs.get_mut(rel) {
-                d.1 -= 1;
-                if d.1 == 0 {
-                    self.dirs.remove(rel);
-                }
+            let Some(dir) = self.dirs.get_mut(rel) else { continue };
+            dir.1 -= 1;
+            if dir.1 > 0 {
+                continue;
             }
+            let Some((_, _, row)) = self.dirs.remove(rel) else { continue };
+            self.dirs_hot.remove(row, &mut self.dirs);
         }
         self.file_count -= 1;
-        self.symbol_count -= old.symbols.len() as u32;
+        self.symbol_count -= old.sym_len;
+        self.compact_if_needed();
         Some(old)
     }
 
@@ -213,6 +680,19 @@ impl IndexData {
         doomed.into_iter().filter(|p| self.remove(p).is_some()).collect()
     }
 
+    /// Reclaims the space of replaced/removed files once it dominates a table.
+    fn compact_if_needed(&mut self) {
+        if self.hot.dead_text > 1 << 16 && self.hot.dead_text * 2 > self.hot.text.len() {
+            self.hot.compact();
+        }
+        if self.syms.dead_rows > 4096 && self.syms.dead_rows * 2 > self.syms.head.len() {
+            self.syms.compact(&mut self.hot.rows, &mut self.files);
+        }
+        if self.dirs_hot.dead > 1 << 16 && self.dirs_hot.dead * 2 > self.dirs_hot.text.len() {
+            self.dirs_hot.compact();
+        }
+    }
+
     /// Releases spare capacity (after large deletions).
     pub(crate) fn shrink(&mut self) {
         while matches!(self.files.last(), Some(None)) {
@@ -221,6 +701,11 @@ impl IndexData {
             self.free.retain(|&s| s != last);
         }
         self.files.shrink_to_fit();
+        self.hot.rows.truncate(self.files.len());
+        self.hot.shrink();
+        self.dirs_hot.shrink();
+        self.syms.compact(&mut self.hot.rows, &mut self.files);
+        self.syms.shrink();
         self.free.shrink_to_fit();
         self.by_path.shrink_to_fit();
         self.dirs.shrink_to_fit();
@@ -248,7 +733,7 @@ fn ancestors(e: &FileEntry) -> impl Iterator<Item = (&str, &Path)> {
 mod tests {
     use super::*;
 
-    fn entry(path: &str, symbols: usize) -> FileEntry {
+    fn entry(path: &str, symbols: usize) -> (FileEntry, Vec<StoredSymbol>) {
         let record = FileRecord {
             symbols: (0..symbols)
                 .map(|i| StoredSymbol {
@@ -263,48 +748,101 @@ mod tests {
         FileEntry::new(PathBuf::from("/r").join(path), path.to_owned(), record)
     }
 
+    fn insert(d: &mut IndexData, path: &str, symbols: usize) {
+        let (e, s) = entry(path, symbols);
+        d.insert(e, s);
+    }
+
+    /// The compact tables must always mirror the entries they were derived from.
+    fn assert_consistent(d: &IndexData) {
+        assert_eq!(d.hot.rows.len(), d.files.len(), "one hot row per slot");
+        assert_eq!(d.hot.rows.iter().filter(|r| r.live).count(), d.file_count as usize, "live rows are files");
+        for (slot, e) in d.files.iter().enumerate() {
+            let Some(e) = e else {
+                assert!(d.hot.row(slot).is_none(), "free slot {slot} has no row");
+                continue;
+            };
+            let row = d.hot.row(slot).unwrap_or_else(|| panic!("slot {slot} has a row"));
+            assert_eq!(row.rel(d.hot.text()), &*e.rel);
+            assert_eq!(row.name(d.hot.text()), e.name());
+            assert_eq!(row.dir(d.hot.text()), e.dir());
+            assert_eq!(row.name_mask, char_mask(e.name()));
+            assert_eq!(row.rel_mask, char_mask(&e.rel));
+            assert_eq!(row.dir_mask, char_mask(e.dir()));
+            assert_eq!(row.ascii, e.rel.is_ascii());
+            assert_eq!(row.sym_start, e.sym_start);
+            assert_eq!(row.sym_len, e.sym_len);
+            assert_eq!(row.sym_mask, d.symbols_of(e).fold(0u64, |m, s| m | char_mask(s.name)));
+            assert_eq!(d.syms.head.len(), d.syms.container.len());
+            assert_eq!(d.syms.head.len(), d.syms.kind.len());
+            assert_eq!(d.syms.head.len(), d.syms.range.len());
+            assert!(e.sym_len == 0 || (e.sym_start as usize) < d.syms.head.len());
+            assert!(e.sym_start + e.sym_len <= d.syms.head.len() as u32);
+        }
+        for (rel, (path, count, row)) in &d.dirs {
+            let row = &d.dirs_hot.rows[*row as usize];
+            assert_eq!(row.rel(d.dirs_hot.text()), &**rel);
+            assert_eq!(&row.path, path);
+            assert!(*count > 0);
+            let trimmed = &rel[..rel.len() - 1];
+            let name = &trimmed[row.name_start as usize..];
+            assert_eq!(row.name_mask, char_mask(name));
+            assert_eq!(row.rel_mask, char_mask(trimmed));
+        }
+        assert_eq!(d.dirs.len(), d.dirs_hot.rows.len());
+        assert_eq!(d.symbol_count, d.files.iter().flatten().map(|e| e.sym_len).sum::<u32>());
+    }
+
     #[test]
     fn dirs_follow_inserts_and_removals() {
         let mut d = IndexData::default();
-        d.insert(entry("a/b/c.rs", 0));
-        d.insert(entry("a/d.rs", 0));
-        d.insert(entry("a/d.rs", 0));
-        d.insert(entry("top.rs", 0));
+        insert(&mut d, "a/b/c.rs", 0);
+        insert(&mut d, "a/d.rs", 0);
+        insert(&mut d, "a/d.rs", 0);
+        insert(&mut d, "top.rs", 0);
         let mut dirs: Vec<_> = d.dirs.iter().map(|(k, v)| (k.to_string(), v.1)).collect();
         dirs.sort();
         assert_eq!(dirs, [("a/".into(), 2), ("a/b/".into(), 1)]);
         assert_eq!(d.dirs["a/b/"].0, PathBuf::from("/r/a/b"));
+        assert_consistent(&d);
         d.remove(Path::new("/r/a/b/c.rs"));
         assert!(!d.dirs.contains_key("a/b/"));
+        assert_consistent(&d);
         d.remove_tree(Path::new("/r/a"));
         assert!(d.dirs.is_empty());
+        assert_consistent(&d);
     }
 
     #[test]
     fn insert_replace_remove_keep_counts() {
         let mut d = IndexData::default();
-        d.insert(entry("a/b.rs", 2));
-        d.insert(entry("c.rs", 1));
+        insert(&mut d, "a/b.rs", 2);
+        insert(&mut d, "c.rs", 1);
         assert_eq!((d.file_count, d.symbol_count), (2, 3));
-        d.insert(entry("a/b.rs", 5));
+        insert(&mut d, "a/b.rs", 5);
         assert_eq!((d.file_count, d.symbol_count), (2, 6));
+        assert_consistent(&d);
         assert!(d.remove(Path::new("/r/c.rs")).is_some());
         assert_eq!((d.file_count, d.symbol_count), (1, 5));
-        d.insert(entry("d.rs", 0));
+        assert_consistent(&d);
+        insert(&mut d, "d.rs", 0);
         assert_eq!(d.files.len(), 2, "slot reused");
+        assert_consistent(&d);
         assert_eq!(d.remove_tree(Path::new("/r/a")), vec![PathBuf::from("/r/a/b.rs")]);
         assert_eq!((d.file_count, d.symbol_count), (1, 0));
         let e = d.get(Path::new("/r/d.rs")).unwrap();
         assert_eq!((e.name(), e.dir()), ("d.rs", ""));
-        d.insert(entry("e.rs", 1));
-        d.insert(entry("f.rs", 1));
+        insert(&mut d, "e.rs", 1);
+        insert(&mut d, "f.rs", 1);
         d.remove(Path::new("/r/e.rs"));
         d.remove(Path::new("/r/f.rs"));
         d.shrink();
+        assert_consistent(&d);
         assert_eq!(d.files.len(), 2, "trailing free slot dropped");
         assert_eq!(d.free, vec![0]);
-        d.insert(entry("g.rs", 1));
+        insert(&mut d, "g.rs", 1);
         assert_eq!((d.file_count, d.files.len()), (2, 2));
+        assert_consistent(&d);
     }
 
     #[test]
@@ -312,4 +850,65 @@ mod tests {
         assert_eq!(char_mask("ab") & char_mask("Bad"), char_mask("ab"));
         assert_ne!(char_mask("z") & char_mask("abc"), char_mask("z"));
     }
+
+    fn insert_symbols(d: &mut IndexData, path: &str, symbols: Vec<StoredSymbol>) {
+        let record = FileRecord { symbols, ..Default::default() };
+        let (e, s) = FileEntry::new(PathBuf::from("/r").join(path), path.to_owned(), record);
+        d.insert(e, s);
+    }
+
+    fn symbol(n: &str) -> StoredSymbol {
+        StoredSymbol { name: n.to_owned(), kind: SymbolKind::Function, container: None, range: Range::default() }
+    }
+
+    #[test]
+    fn compaction_keeps_entries_and_records_in_sync() {
+        let mut d = IndexData::default();
+        insert(&mut d, "a.rs", 3);
+        insert(&mut d, "b/c.rs", 2);
+        insert_symbols(&mut d, "a.rs", vec![symbol("fresh")]);
+        d.shrink();
+        assert_consistent(&d);
+        assert_eq!(d.syms.head.len() as u32, d.symbol_count, "compaction drops dead symbol rows");
+        let names = |d: &IndexData, p: &str| -> Vec<String> {
+            let e = d.get(Path::new(p)).unwrap();
+            d.record(e).symbols.into_iter().map(|s| s.name).collect()
+        };
+        assert_eq!(names(&d, "/r/a.rs"), ["fresh"]);
+        assert_eq!(names(&d, "/r/b/c.rs"), ["s0", "s1"]);
+        assert_eq!(d.symbol_count, 3);
+    }
+
+    #[test]
+    fn large_replacements_reclaim_symbol_storage() {
+        let mut d = IndexData::default();
+        insert_symbols(&mut d, "a.rs", (0..5_000).map(|i| symbol(&format!("old{i}"))).collect());
+        assert_eq!(d.syms.head.len(), 5_000);
+        insert_symbols(&mut d, "a.rs", vec![symbol("fresh")]);
+        assert_eq!(d.syms.head.len(), 1, "dead symbol rows are reclaimed");
+        assert_eq!((d.symbol_count, d.file_count), (1, 1));
+        assert_consistent(&d);
+    }
+
+    #[test]
+    fn tree_removal_leaves_no_hot_rows_or_dirs() {
+        let mut d = IndexData::default();
+        insert(&mut d, "a/b/one.rs", 2);
+        insert(&mut d, "a/b/two.rs", 3);
+        insert(&mut d, "a/three.rs", 1);
+        insert(&mut d, "elsewhere/four.rs", 1);
+        assert_eq!(d.remove_tree(Path::new("/r/a")).len(), 3);
+        assert_consistent(&d);
+        assert_eq!(d.hot.rows.iter().filter(|r| r.live).count(), 1);
+        assert!(d.hot.row(0).is_none(), "removed slots have no live row");
+        assert_eq!(d.dirs.len(), 1, "elsewhere/ only");
+        assert_eq!(d.dirs_hot.rows.len(), 1);
+        assert_eq!(d.symbol_count, 1);
+        d.shrink();
+        assert_eq!(d.syms.head.len() as u32, d.symbol_count);
+        // Slots are reusable and the new row replaces the tombstone.
+        insert(&mut d, "a/five.rs", 2);
+        assert_consistent(&d);
+        assert_eq!(d.file_count, 2);
+    }
 }

crates/ide-index/src/lib.rs

@@ -199,12 +199,11 @@ impl ProjectIndex {
             return None;
         }
         Some(
-            file.symbols
-                .iter()
+            data.symbols_of(file)
                 .map(|s| ide_language::SymbolTag {
                     name: s.name.to_string(),
                     kind: s.kind,
-                    container: s.container.as_ref().map(ToString::to_string),
+                    container: s.container.map(ToString::to_string),
                     range: s.range,
                 })
                 .collect(),
@@ -231,7 +230,7 @@ impl ProjectIndex {
     pub fn find_files(&self, query: &str, limit: usize) -> Vec<FileMatch> {
         let recent = self.shared.recent.lock().clone();
         let d = self.shared.data.read();
-        matching::find_files(&d, &matching::Recents { paths: &recent }, query, limit)
+        matching::find_files(&d, &matching::Recents::new(&recent), query, limit)
     }
 
     /// All indexed files with this exact basename, for resolving printed source locations.
@@ -274,7 +273,7 @@ impl ProjectIndex {
     pub fn find_symbols(&self, query: &str, filter: SymbolFilter, limit: usize) -> Vec<SymbolMatch> {
         let recent = self.shared.recent.lock().clone();
         let d = self.shared.data.read();
-        matching::find_symbols(&d, &matching::Recents { paths: &recent }, query, filter, limit)
+        matching::find_symbols(&d, &matching::Recents::new(&recent), query, filter, limit)
     }
 
     /// Scoped symbol search with cooperative interruption, including lock waits.
@@ -303,15 +302,7 @@ impl ProjectIndex {
                 break data;
             }
         };
-        matching::find_symbols_until(
-            &data,
-            &matching::Recents { paths: &recent },
-            query,
-            filter,
-            limit,
-            include,
-            stopped,
-        )
+        matching::find_symbols_until(&data, &matching::Recents::new(&recent), query, filter, limit, include, stopped)
     }
 
     /// Symbols named exactly `name` (of `kind`, if given): `.card` selectors for `class="card"`.
@@ -523,7 +514,8 @@ pub mod bench_support {
                     })
                     .collect();
                 let record = FileRecord { symbols, ..Default::default() };
-                data.insert(FileEntry::new(PathBuf::from("/bench").join(&rel), rel, record));
+                let (entry, symbols) = FileEntry::new(PathBuf::from("/bench").join(&rel), rel, record);
+                data.insert(entry, symbols);
             }
             let recent = data.paths().take(MAX_RECENT).cloned().collect();
             Self { data, recent }
@@ -538,7 +530,7 @@ pub mod bench_support {
         }
 
         pub fn find_files(&self, query: &str, limit: usize) -> Vec<FileMatch> {
-            matching::find_files(&self.data, &matching::Recents { paths: &self.recent }, query, limit)
+            matching::find_files(&self.data, &matching::Recents::new(&self.recent), query, limit)
         }
 
         pub fn find_dirs(&self, query: &str, limit: usize) -> Vec<FileMatch> {
@@ -546,7 +538,7 @@ pub mod bench_support {
         }
 
         pub fn find_symbols(&self, query: &str, filter: SymbolFilter, limit: usize) -> Vec<SymbolMatch> {
-            matching::find_symbols(&self.data, &matching::Recents { paths: &self.recent }, query, filter, limit)
+            matching::find_symbols(&self.data, &matching::Recents::new(&self.recent), query, filter, limit)
         }
     }
 }

crates/ide-index/src/matching.rs

@@ -4,14 +4,19 @@
 //! (bit-mask pre-filter, nucleo score, exact/prefix boosts) and keeps the best
 //! few; the survivors then get match indices, CamelHump and recency boosts and
 //! are re-sorted.
+//!
+//! The scan streams the compact tables in `data` (`HotFiles`/`HotDirs`/`SymTable`):
+//! only the hot fields per candidate and strings from contiguous arenas, with the
+//! thread-local matcher and one UTF-32 buffer per scan rather than per candidate.
 
-use crate::data::{FileEntry, IndexData, char_mask};
+use crate::data::{DirRow, FileEntry, FileRow, IndexData, SymTable, char_mask};
 use crate::{FileMatch, SymbolFilter, SymbolMatch};
 use ide_core::SymbolKind;
 use nucleo_matcher::{Config, Matcher, Utf32Str, Utf32String};
 use rayon::prelude::*;
 use std::cell::RefCell;
 use std::cmp::Ordering;
+use std::collections::HashMap;
 use std::path::{Path, PathBuf};
 
 const TIER_NAME: u32 = 1 << 20;
@@ -54,6 +59,11 @@ impl Needle {
         m.fuzzy_match(Utf32Str::new(hay, buf), self.utf32.slice(..)).map(u32::from)
     }
 
+    /// `hay` is pure ASCII: skip `Utf32Str::new`'s check and UTF-32 conversion.
+    fn score_ascii(&self, m: &mut Matcher, hay: &str) -> Option<u32> {
+        m.fuzzy_match(Utf32Str::Ascii(hay.as_bytes()), self.utf32.slice(..)).map(u32::from)
+    }
+
     fn indices(&self, m: &mut Matcher, hay: &str, buf: &mut Vec<char>, out: &mut Vec<u32>) -> Option<u32> {
         out.clear();
         let s = m.fuzzy_indices(Utf32Str::new(hay, buf), self.utf32.slice(..), out).map(u32::from);
@@ -105,6 +115,9 @@ struct Cand {
     slot: u32,
     sym: u32,
     score: u32,
+    /// Candidate name/rel length: the first tie-break key, cached so ranking a pool
+    /// does not chase it through the tables.
+    len: u32,
 }
 
 fn keep_best(mut v: Vec<Cand>, k: usize, tiebreak: &impl Fn(&Cand, &Cand) -> Ordering) -> Vec<Cand> {
@@ -119,7 +132,7 @@ fn scan(
     data: &IndexData,
     pool: usize,
     tiebreak: &(impl Fn(&Cand, &Cand) -> Ordering + Sync),
-    per_file: impl Fn(u32, &FileEntry, &mut Vec<Cand>) + Sync,
+    per_file: impl Fn(u32, &FileRow, &mut Matcher, &mut Vec<Cand>) + Sync,
 ) -> Vec<Cand> {
     scan_until(data, pool, tiebreak, &|| false, per_file).unwrap_or_default()
 }
@@ -129,18 +142,22 @@ fn scan_until(
     pool: usize,
     tiebreak: &(impl Fn(&Cand, &Cand) -> Ordering + Sync),
     stopped: &(impl Fn() -> bool + Sync),
-    per_file: impl Fn(u32, &FileEntry, &mut Vec<Cand>) + Sync,
+    per_file: impl Fn(u32, &FileRow, &mut Matcher, &mut Vec<Cand>) + Sync,
 ) -> Option<Vec<Cand>> {
-    data.files
+    // One row per slot, so this is exactly the old scan over `files`: same item
+    // order and count, and free slots are skipped exactly like `None` was, keeping
+    // the pruning boundaries (and therefore the candidate pool) unchanged.
+    data.hot
+        .rows
         .par_iter()
         .enumerate()
         .with_min_len(256)
-        .try_fold(Vec::new, |mut acc, (slot, e)| {
+        .try_fold(Vec::new, |mut acc, (slot, row)| {
             if stopped() {
                 return None;
             }
-            if let Some(e) = e {
-                per_file(slot as u32, e, &mut acc);
+            if row.live {
+                with_matcher(|m| per_file(slot as u32, row, m, &mut acc));
                 if acc.len() >= pool * 2 {
                     acc = keep_best(acc, pool, tiebreak);
                 }
@@ -155,15 +172,22 @@ fn scan_until(
 
 pub(crate) struct Recents<'a> {
     pub paths: &'a [PathBuf],
+    /// Position of each path, so ranking a survivor does not scan the list.
+    /// Duplicates keep their first position, like `position`.
+    ranks: HashMap<&'a Path, usize>,
 }
 
-impl Recents<'_> {
-    fn rank(&self, path: &std::path::Path) -> Option<usize> {
-        self.paths.iter().position(|p| p == path)
+impl<'a> Recents<'a> {
+    pub(crate) fn new(paths: &'a [PathBuf]) -> Self {
+        let mut ranks = HashMap::with_capacity(paths.len());
+        for (i, p) in paths.iter().enumerate() {
+            ranks.entry(p.as_path()).or_insert(i);
+        }
+        Self { paths, ranks }
     }
 
-    fn bonus(&self, path: &std::path::Path) -> u32 {
-        self.rank(path).map_or(0, |r| RECENT_MAX.saturating_sub(r as u32 * 12))
+    fn bonus(&self, path: &Path) -> u32 {
+        self.ranks.get(path).map_or(0, |&r| RECENT_MAX.saturating_sub(r as u32 * 12))
     }
 }
 
@@ -209,29 +233,31 @@ pub(crate) fn find_files(data: &IndexData, recents: &Recents, query: &str, limit
         Some((dir, name)) => FileQuery::Path { dir: Needle::new(dir), name: Needle::new(name) },
         None => FileQuery::Name(Needle::new(&q)),
     };
-    let tiebreak = |a: &Cand, b: &Cand| {
-        let (ea, eb) = (file(data, a.slot), file(data, b.slot));
-        ea.rel.len().cmp(&eb.rel.len()).then_with(|| ea.rel.cmp(&eb.rel))
-    };
+    let tiebreak = |a: &Cand, b: &Cand| a.len.cmp(&b.len).then_with(|| data.hot.rel(a.slot).cmp(data.hot.rel(b.slot)));
     let pool = limit * 4 + 64;
-    let mut cands = scan(data, pool, &tiebreak, |slot, e, acc| {
+    let mut cands = scan(data, pool, &tiebreak, |slot, row, m, acc| {
         let mut buf = Vec::new();
-        if let Some(score) = with_matcher(|m| base_file_score(m, &fq, e, &mut buf)) {
-            acc.push(Cand { slot, sym: u32::MAX, score });
+        if let Some(score) = base_file_score(m, &fq, row, data.hot.text(), &mut buf) {
+            acc.push(Cand { slot, sym: u32::MAX, score, len: row.rel.len });
         }
     });
     // Recent files always compete for the final ranking.
-    for p in recents.paths {
-        if let Some(e) = data.get(p) {
+    with_matcher(|m| {
+        let mut buf = Vec::new();
+        for p in recents.paths {
+            if data.get(p).is_none() {
+                continue;
+            }
             let Some(slot) = data.slot(p) else { continue };
-            if !cands.iter().any(|c| c.slot == slot) {
-                let mut buf = Vec::new();
-                if let Some(score) = with_matcher(|m| base_file_score(m, &fq, e, &mut buf)) {
-                    cands.push(Cand { slot, sym: u32::MAX, score });
-                }
+            if cands.iter().any(|c| c.slot == slot) {
+                continue;
+            }
+            let Some(row) = data.hot.row_of_slot(slot) else { continue };
+            if let Some(score) = base_file_score(m, &fq, row, data.hot.text(), &mut buf) {
+                cands.push(Cand { slot, sym: u32::MAX, score, len: row.rel.len });
             }
         }
-    }
+    });
     let mut out: Vec<(u32, &FileEntry, Vec<u32>)> = with_matcher(|m| {
         let mut buf = Vec::new();
         cands
@@ -273,30 +299,46 @@ pub(crate) fn find_dirs(data: &IndexData, query: &str, limit: usize) -> Vec<File
     }
     let by_path = q.contains('/');
     let needle = Needle::new(q.trim_end_matches('/'));
+    let text = data.dirs_hot.text();
     // (score, rel without the trailing `/`, char offset of the name when it matched by name)
-    let score = |m: &mut Matcher, buf: &mut Vec<char>, rel: &str| -> Option<(u32, Option<u32>)> {
-        let trimmed = &rel[..rel.len() - 1];
-        let start = trimmed.rfind('/').map_or(0, |i| i + 1);
-        let name = &trimmed[start..];
-        if !by_path
-            && needle.mask & char_mask(name) == needle.mask
-            && let Some(s) = needle.score(m, name, buf)
-        {
-            return Some((TIER_NAME + s * 4 + needle.name_boost(name), Some(trimmed[..start].chars().count() as u32)));
-        }
-        if needle.mask & char_mask(trimmed) != needle.mask {
-            return None;
-        }
-        needle.score(m, trimmed, buf).map(|s| (s, None))
-    };
-    let mut best: Vec<(u32, &str, &Path, Option<u32>)> = data
-        .dirs
+    let (mut best, _): (Vec<_>, Vec<char>) = data
+        .dirs_hot
+        .rows
         .par_iter()
-        .filter_map(|(rel, (path, _))| {
-            let mut buf = Vec::new();
-            with_matcher(|m| score(m, &mut buf, rel)).map(|(s, at)| (s, &**rel, path.as_path(), at))
-        })
-        .collect();
+        .fold(
+            || (Vec::new(), Vec::new()),
+            |(mut found, mut buf), row: &DirRow| {
+                let rel = row.rel(text);
+                let trimmed = &rel[..rel.len() - 1];
+                let name = &trimmed[row.name_start as usize..];
+                with_matcher(|m| {
+                    let hit = if !by_path
+                        && needle.mask & row.name_mask == needle.mask
+                        && let Some(s) = needle.score(m, name, &mut buf)
+                    {
+                        Some((
+                            TIER_NAME + s * 4 + needle.name_boost(name),
+                            Some(trimmed[..row.name_start as usize].chars().count() as u32),
+                        ))
+                    } else if needle.mask & row.rel_mask != needle.mask {
+                        None
+                    } else {
+                        needle.score(m, trimmed, &mut buf).map(|s| (s, None))
+                    };
+                    if let Some((s, at)) = hit {
+                        found.push((s, rel, row.path.as_path(), at));
+                    }
+                });
+                (found, buf)
+            },
+        )
+        .reduce(
+            || (Vec::new(), Vec::new()),
+            |mut a, b| {
+                a.0.extend(b.0);
+                a
+            },
+        );
     let order = |a: &(u32, &str, &Path, Option<u32>), b: &(u32, &str, &Path, Option<u32>)| {
         b.0.cmp(&a.0).then_with(|| a.1.len().cmp(&b.1.len())).then_with(|| a.1.cmp(b.1))
     };
@@ -338,33 +380,39 @@ fn file(data: &IndexData, slot: u32) -> &FileEntry {
     data.files[slot as usize].as_ref().expect("candidate slots are live")
 }
 
-fn base_file_score(m: &mut Matcher, q: &FileQuery, e: &FileEntry, buf: &mut Vec<char>) -> Option<u32> {
+fn base_file_score(m: &mut Matcher, q: &FileQuery, row: &FileRow, text: &str, buf: &mut Vec<char>) -> Option<u32> {
+    // Strings are sliced only once their mask passes, so a rejected row costs two masks.
     match q {
         FileQuery::Name(n) => {
-            if n.mask & e.name_mask == n.mask
-                && let Some(s) = n.score(m, e.name(), buf)
-            {
-                return Some(TIER_NAME + s * 4 + n.name_boost(e.name()));
+            if n.mask & row.name_mask == n.mask {
+                let name = row.name(text);
+                let s = if row.ascii { n.score_ascii(m, name) } else { n.score(m, name, buf) };
+                if let Some(s) = s {
+                    return Some(TIER_NAME + s * 4 + n.name_boost(name));
+                }
             }
-            if n.mask & e.rel_mask == n.mask {
-                return n.score(m, &e.rel, buf);
+            if n.mask & row.rel_mask == n.mask {
+                let rel = row.rel(text);
+                return if row.ascii { n.score_ascii(m, rel) } else { n.score(m, rel, buf) };
             }
             None
         }
-        FileQuery::Path { dir, name } => {
-            let name_score = if name.is_empty() {
+        FileQuery::Path { dir, name: n } => {
+            let name_score = if n.is_empty() {
                 0
             } else {
-                if name.mask & e.name_mask != name.mask {
+                if n.mask & row.name_mask != n.mask {
                     return None;
                 }
-                name.score(m, e.name(), buf)? * 4 + name.name_boost(e.name())
+                let name = row.name(text);
+                let s = if row.ascii { n.score_ascii(m, name) } else { n.score(m, name, buf) }?;
+                s * 4 + n.name_boost(name)
             };
-            let dir_str = e.dir();
-            if dir.mask & char_mask(dir_str) != dir.mask {
+            if dir.mask & row.dir_mask != dir.mask {
                 return None;
             }
-            let dir_score = dir.score(m, dir_str, buf)?;
+            let dir_str = row.dir(text);
+            let dir_score = if row.ascii { dir.score_ascii(m, dir_str) } else { dir.score(m, dir_str, buf) }?;
             Some(TIER_NAME + name_score + dir_score)
         }
     }
@@ -396,22 +444,21 @@ fn symbol_score(
     m: &mut Matcher,
     name: &Needle,
     container: Option<&Needle>,
-    s: &crate::data::Sym,
+    syms: &SymTable,
+    i: u32,
     buf: &mut Vec<char>,
 ) -> Option<u32> {
-    if name.mask & s.mask != name.mask {
-        return None;
-    }
-    let mut score = if name.is_empty() { 0 } else { name.score(m, &s.name, buf)? * 4 };
-    score += name.name_boost(&s.name);
+    let symbol = syms.name(i);
+    let mut score = if name.is_empty() { 0 } else { name.score(m, symbol, buf)? * 4 };
+    score += name.name_boost(symbol);
     if let Some(cq) = container {
-        let c = s.container.as_deref()?;
+        let c = syms.container(i)?;
         if cq.mask & char_mask(c) != cq.mask {
             return None;
         }
         score += cq.score(m, c, buf)? + cq.name_boost(c) / 4;
     }
-    if s.kind.is_type_like() {
+    if syms.kind(i).is_type_like() {
         score += TYPE_LIKE;
     }
     Some(score)
@@ -455,30 +502,35 @@ pub(crate) fn find_symbols_until(
     let (container_q, name_q) = split_symbol_query(&q);
     let name = Needle::new(name_q);
     let container = container_q.map(Needle::new);
-    let sym = |c: &Cand| &file(data, c.slot).symbols[c.sym as usize];
-    let tiebreak = |a: &Cand, b: &Cand| {
-        let (sa, sb) = (sym(a), sym(b));
-        sa.name.len().cmp(&sb.name.len()).then_with(|| file(data, a.slot).rel.cmp(&file(data, b.slot).rel))
-    };
+    let syms = &data.syms;
+    let tiebreak = |a: &Cand, b: &Cand| a.len.cmp(&b.len).then_with(|| data.hot.rel(a.slot).cmp(data.hot.rel(b.slot)));
     let pool = limit * 4 + 64;
-    let cands = scan_until(data, pool, &tiebreak, stopped, |slot, e, acc| {
-        if e.symbols.is_empty() || !include(&e.path) {
+    let cands = scan_until(data, pool, &tiebreak, stopped, |slot, row, m, acc| {
+        // Whole-file pre-filter: when the union of the file's symbol masks
+        // already misses a query character, no symbol can match.
+        if row.sym_len == 0 || name.mask & row.sym_mask != name.mask {
             return;
         }
-        with_matcher(|m| {
-            let mut buf = Vec::new();
-            for (i, s) in e.symbols.iter().enumerate() {
-                if stopped() {
-                    break;
-                }
-                if filter == SymbolFilter::Types && !s.kind.is_type_like() {
-                    continue;
-                }
-                if let Some(score) = symbol_score(m, &name, container.as_ref(), s, &mut buf) {
-                    acc.push(Cand { slot, sym: i as u32, score });
-                }
+        let e = file(data, slot);
+        if !include(&e.path) {
+            return;
+        }
+        let mut buf = Vec::new();
+        for (k, head) in syms.heads(row.sym_start, row.sym_len).iter().enumerate() {
+            if stopped() {
+                break;
             }
-        });
+            if filter == SymbolFilter::Types && !syms.kind(row.sym_start + k as u32).is_type_like() {
+                continue;
+            }
+            if name.mask & head.mask != name.mask {
+                continue;
+            }
+            let i = row.sym_start + k as u32;
+            if let Some(score) = symbol_score(m, &name, container.as_ref(), syms, i, &mut buf) {
+                acc.push(Cand { slot, sym: i, score, len: head.name.len });
+            }
+        }
     })?;
     if stopped() {
         return None;
@@ -489,33 +541,32 @@ pub(crate) fn find_symbols_until(
             .into_iter()
             .take_while(|_| !stopped())
             .filter_map(|c| {
-                let s = sym(&c);
+                let symbol = syms.name(c.sym);
                 let e = file(data, c.slot);
                 let mut idx = Vec::new();
                 if !name.is_empty() {
-                    name.indices(m, &s.name, &mut buf, &mut idx)?;
+                    name.indices(m, symbol, &mut buf, &mut idx)?;
                 }
-                let bonus = hump_bonus(&s.name, &idx) + recents.bonus(&e.path) / 4;
+                let bonus = hump_bonus(symbol, &idx) + recents.bonus(&e.path) / 4;
                 Some((c.score + bonus, c, idx))
             })
             .collect()
     });
     out.sort_by(|a, b| {
-        b.0.cmp(&a.0).then_with(|| tiebreak(&a.1, &b.1)).then_with(|| sym(&a.1).range.cmp(&sym(&b.1).range))
+        b.0.cmp(&a.0).then_with(|| tiebreak(&a.1, &b.1)).then_with(|| syms.range(a.1.sym).cmp(&syms.range(b.1.sym)))
     });
     out.truncate(limit);
     let results = out
         .into_iter()
         .map(|(score, c, indices)| {
             let e = file(data, c.slot);
-            let s = &e.symbols[c.sym as usize];
             SymbolMatch {
-                name: s.name.to_string(),
-                kind: s.kind,
-                container: s.container.as_deref().map(str::to_owned),
+                name: syms.name(c.sym).to_string(),
+                kind: syms.kind(c.sym),
+                container: syms.container(c.sym).map(str::to_owned),
                 path: e.path.clone().into(),
                 rel_path: e.rel.to_string(),
-                range: s.range,
+                range: syms.range(c.sym),
                 score,
                 indices,
             }
@@ -541,24 +592,25 @@ pub(crate) fn symbols_named_within(
 ) -> Vec<SymbolMatch> {
     let mask = char_mask(name);
     let within = |e: &FileEntry| roots.is_empty() || roots.iter().any(|root| e.path.starts_with(root));
+    let syms = &data.syms;
     let mut out: Vec<SymbolMatch> = data
         .files
         .iter()
         .flatten()
         .filter(|e| within(e))
         .flat_map(|e| {
-            e.symbols.iter().filter(|s| s.mask == mask && &*s.name == name && kind.is_none_or(|k| s.kind == k)).map(
-                move |s| SymbolMatch {
-                    name: s.name.to_string(),
-                    kind: s.kind,
-                    container: s.container.as_deref().map(str::to_owned),
+            (e.sym_start..e.sym_start + e.sym_len)
+                .filter(|&i| syms.mask(i) == mask && syms.name(i) == name && kind.is_none_or(|k| syms.kind(i) == k))
+                .map(move |i| SymbolMatch {
+                    name: syms.name(i).to_string(),
+                    kind: syms.kind(i),
+                    container: syms.container(i).map(str::to_owned),
                     path: e.path.clone().into(),
                     rel_path: e.rel.to_string(),
-                    range: s.range,
+                    range: syms.range(i),
                     score: 0,
                     indices: Vec::new(),
-                },
-            )
+                })
         })
         .collect();
     out.sort_by(|a, b| a.rel_path.cmp(&b.rel_path).then_with(|| a.range.cmp(&b.range)));

crates/ide-index/src/worker.rs

@@ -173,7 +173,7 @@ impl Shared {
         let root = filter.root().to_owned();
         match store.load() {
             Ok(records) => {
-                let entries: Vec<FileEntry> = records
+                let entries: Vec<(FileEntry, Vec<StoredSymbol>)> = records
                     .into_par_iter()
                     .filter(|(rel, _)| {
                         let path = root.join(rel);
@@ -182,8 +182,8 @@ impl Shared {
                     .map(|(rel, rec)| FileEntry::new(root.join(&rel), rel, rec))
                     .collect();
                 let mut d = self.data.write();
-                for e in entries {
-                    d.insert(e);
+                for (e, symbols) in entries {
+                    d.insert(e, symbols);
                 }
             }
             Err(e) => tracing::warn!("index cache load failed: {e}"),
@@ -321,8 +321,7 @@ impl Shared {
                 match self.extract(f, prev_hash) {
                     Extracted::Unchanged => {
                         // Same content, new mtime: keep the symbols, refresh metadata.
-                        let d = self.data.read();
-                        let mut rec = d.get(&f.path)?.record();
+                        let mut rec = self.data.read().record_of(&f.path)?;
                         rec.mtime = f.mtime;
                         rec.size = f.size;
                         rec.ignored = f.ignored;
@@ -338,11 +337,11 @@ impl Shared {
         let puts: Vec<(String, FileRecord)> =
             extracted.iter().filter_map(|(_, rec, path)| Some((filter.store_key(path)?, rec.clone()))).collect();
         {
-            let entries: Vec<FileEntry> =
+            let entries: Vec<(FileEntry, Vec<StoredSymbol>)> =
                 extracted.into_iter().map(|(rel, rec, path)| FileEntry::new(path, rel, rec)).collect();
             let mut d = self.data.write();
-            for e in entries {
-                d.insert(e);
+            for (e, symbols) in entries {
+                d.insert(e, symbols);
             }
         }
         self.persist(&puts, &[], false);

crates/ide-jsonrpc/src/lib.rs

@@ -223,6 +223,10 @@ pub trait Handler: Send + Sync + 'static {
 
     /// Called once the response to a `method` request is queued: what it sends follows the response.
     fn after_response(&self, _method: &str) {}
+
+    /// Adjusts every message from the peer (responses included) before it is dispatched, e.g.
+    /// to repair values the peer spells more loosely than the types that read them accept.
+    fn normalize_incoming(&self, _message: &mut Value) {}
 }
 
 /// A [`Handler`] that ignores notifications and rejects requests.
@@ -585,9 +589,10 @@ impl Peer {
                 .expect("spawn jsonrpc notification thread");
         }
 
-        // Reader: parses and dispatches; never runs handler code itself.
+        // Reader: parses and dispatches; runs no handler code beyond `normalize_incoming`.
         {
             let inner = inner.clone();
+            let handler = handler.clone();
             tokio::spawn(async move {
                 let mut reader = BufReader::new(reader);
                 let seen_message = AtomicBool::new(false);
@@ -610,7 +615,7 @@ impl Peer {
                     match msg {
                         Ok(Some(body)) => {
                             seen_message.store(true, Ordering::Relaxed);
-                            dispatch(&inner, &notif_tx, &body);
+                            dispatch(&inner, &*handler, &notif_tx, &body);
                         }
                         Ok(None) => break,
                         Err(e) => {
@@ -783,15 +788,16 @@ async fn handle_request(inner: Arc<Inner>, handler: Arc<dyn Handler>, id: Value,
     }
 }
 
-fn dispatch(inner: &Arc<Inner>, notif_tx: &std::sync::mpsc::Sender<Incoming>, body: &[u8]) {
+fn dispatch(inner: &Arc<Inner>, handler: &dyn Handler, notif_tx: &std::sync::mpsc::Sender<Incoming>, body: &[u8]) {
     tracing::trace!(target: "ide_jsonrpc::wire", "<-- {}", String::from_utf8_lossy(body));
-    let msg: Value = match serde_json::from_slice(body) {
+    let mut msg: Value = match serde_json::from_slice(body) {
         Ok(v) => v,
         Err(e) => {
             tracing::warn!("jsonrpc: unparsable message: {e}");
             return;
         }
     };
+    handler.normalize_incoming(&mut msg);
     let Value::Object(mut obj) = msg else {
         tracing::warn!("jsonrpc: ignoring non-object message");
         return;

crates/ide-jsonrpc/src/tests.rs

@@ -541,3 +541,29 @@ async fn output_before_the_handshake_is_reported_not_dropped() {
     assert!(lines.iter().any(|l| l == "python: not found"), "{lines:?}");
     assert!(lines.iter().any(|l| l.ends_with(". . .") && l.len() > 6), "{lines:?}");
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn incoming_messages_are_normalized_before_dispatch() {
+    struct Server;
+    impl Handler for Server {
+        fn on_notification(&self, _: &str, _: Value) {}
+        fn on_request(&self, _: &str, params: Value) -> Result<Value, (i64, String)> {
+            Ok(params)
+        }
+    }
+    struct Client;
+    impl Handler for Client {
+        fn on_notification(&self, _: &str, _: Value) {}
+        fn on_request(&self, _: &str, _: Value) -> Result<Value, (i64, String)> {
+            Err((codes::METHOD_NOT_FOUND, "no".into()))
+        }
+        fn normalize_incoming(&self, message: &mut Value) {
+            if let Some(result) = message.get_mut("result") {
+                *result = json!("normalized");
+            }
+        }
+    }
+    let (client, _server) = pair(Arc::new(Client), Arc::new(Server));
+    let v: Value = client.request("echo", "raw", None).await.unwrap();
+    assert_eq!(v, json!("normalized"));
+}

crates/ide-language/src/registry.rs

@@ -79,6 +79,7 @@ const BUILTIN: &[(&str, &str)] = &[
     ("scala", include_str!("../../../languages/scala.toml")),
     ("scss", include_str!("../../../languages/scss.toml")),
     ("shellscript", include_str!("../../../languages/shellscript.toml")),
+    ("slint", include_str!("../../../languages/slint.toml")),
     ("sql", include_str!("../../../languages/sql.toml")),
     ("svelte", include_str!("../../../languages/svelte.toml")),
     ("swift", include_str!("../../../languages/swift.toml")),
@@ -1046,6 +1047,7 @@ mod tests {
             ("icon.svg.import", "godot-resource"),
             ("export_presets.cfg", "godot-resource"),
             ("water.gdshader", "gdshader"),
+            ("app-window.slint", "slint"),
             ("notes.txt", "plaintext"),
         ];
         for (path, id) in cases {

crates/ide-lsp/src/handler.rs

@@ -223,6 +223,8 @@ impl ClientHandler {
         if self.server.running_gen(self.generation).is_some_and(|run| !run.caps.read().restriction.diagnostics()) {
             return;
         }
+        let mut params = params;
+        crate::virtual_doc::normalize_uris(&mut params);
         let params: lsp::PublishDiagnosticsParams = match serde_json::from_value(params) {
             Ok(p) => p,
             Err(e) => {
@@ -250,7 +252,14 @@ impl ClientHandler {
         {
             return;
         }
-        let shown = self.server.set_diagnostics(path.clone(), params.diagnostics);
+        // A late answer for an older version of the text is shown, but isn't fresh (`check_files`).
+        let obsolete =
+            params.version.is_some_and(|v| mgr.docs.lock().values().any(|d| d.path == path && d.version > v));
+        let shown = if obsolete {
+            self.server.set_obsolete_diagnostics(path.clone(), params.diagnostics)
+        } else {
+            self.server.set_diagnostics(path.clone(), params.diagnostics)
+        };
         mgr.emit_diagnostics(&self.server, path, shown, self.encoding());
     }
 
@@ -315,11 +324,13 @@ impl ClientHandler {
     }
 
     fn apply_edit(&self, mgr: &LspManager, params: Value) -> Result<Value, (i64, String)> {
-        let edit: lsp::WorkspaceEdit = params
-            .get("edit")
-            .cloned()
-            .ok_or_else(|| (codes::INVALID_PARAMS, "missing edit".to_owned()))
-            .and_then(|e| serde_json::from_value(e).map_err(|e| (codes::INVALID_PARAMS, e.to_string())))?;
+        let edit: lsp::WorkspaceEdit =
+            params.get("edit").cloned().ok_or_else(|| (codes::INVALID_PARAMS, "missing edit".to_owned())).and_then(
+                |mut e| {
+                    crate::virtual_doc::normalize_uris(&mut e);
+                    serde_json::from_value(e).map_err(|e| (codes::INVALID_PARAMS, e.to_string()))
+                },
+            )?;
         // 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() {
@@ -380,6 +391,10 @@ fn tsserver_ran_out_of_memory(text: &str) -> bool {
 }
 
 impl Handler for ClientHandler {
+    fn normalize_incoming(&self, message: &mut Value) {
+        crate::uri::encode_loose_file_uris(message);
+    }
+
     fn on_notification(&self, method: &str, params: Value) {
         let Some(mgr) = self.mgr.upgrade() else { return };
         match method {

crates/ide-lsp/src/inspect.rs

@@ -239,6 +239,9 @@ impl LspManager {
         cancel: &CancellationToken,
     ) -> IdeResult<DocumentCheck> {
         let snap = self.snapshot(doc)?;
+        // The text may have changed before this call synced it (the file watcher reloaded it):
+        // only diagnostics published after the servers got the current text are fresh.
+        let changed = Some(changed.map_or(snap.changed, |c| c.max(snap.changed)));
         let deadline = tokio::time::Instant::now() + timeout;
         let left = || deadline.saturating_duration_since(tokio::time::Instant::now());
         let ready = tokio::select! {

crates/ide-lsp/src/jdtls.rs

@@ -809,6 +809,21 @@ impl LspManager {
             .map_err(|e| crate::rpc_err(&server.name, "java/projectConfigurationsUpdate", e))
     }
 
+    /// Asks jdtls to re-read library archives replaced in place (`openidea.java.refreshArchives`):
+    /// a SNAPSHOT installed again keeps its path, and JDT would keep showing the classes it read
+    /// from the old archive. Best-effort: skipped while jdtls is not already running.
+    pub async fn java_refresh_archives(&self, path: &Path, archives: &[PathBuf]) -> IdeResult<()> {
+        let java = LanguageId::new("java");
+        let Some(server) = self.servers_for(&java, path).into_iter().find(|s| s.name == SERVER) else {
+            return Ok(());
+        };
+        if server.running().is_none() {
+            return Ok(());
+        }
+        let archives = archives.iter().map(|a| Value::String(a.to_string_lossy().into_owned())).collect();
+        self.jdtls_command(path, "openidea.java.refreshArchives", archives).await.map(|_| ())
+    }
+
     /// 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.

crates/ide-lsp/src/lib.rs

@@ -120,6 +120,8 @@ struct DocState {
     compose_detected: bool,
     /// The notebook a code cell belongs to: synced through `notebookDocument/*`, not as a file.
     notebook: Option<PathBuf>,
+    /// When the servers last got new text (open or change): diagnostics published before are stale.
+    changed: std::time::Instant,
 }
 
 impl DocState {
@@ -158,6 +160,8 @@ struct DocSnap {
     language: LanguageId,
     text: Arc<DocText>,
     servers: Vec<Arc<Server>>,
+    /// [`DocState::changed`].
+    changed: std::time::Instant,
 }
 
 impl DocSnap {
@@ -237,6 +241,9 @@ pub struct LspManager {
     virtual_origins: Mutex<HashMap<String, ide_core::ServerId>>,
     /// Contents fetched for virtual URIs.
     virtual_docs: Mutex<HashMap<String, VirtualDocument>>,
+    /// Modification time of the archive behind a cached library class, so a jar
+    /// replaced in place (a SNAPSHOT installed again) is read again.
+    virtual_stamps: Mutex<HashMap<String, std::time::SystemTime>>,
     injections: injections::State,
     /// Open notebooks by path. Locked before `docs` when both are.
     notebooks: Mutex<HashMap<PathBuf, notebook::NotebookState>>,
@@ -504,6 +511,7 @@ impl LspManager {
             go_mod_checked: Mutex::new(HashSet::new()),
             virtual_origins: Mutex::new(HashMap::new()),
             virtual_docs: Mutex::new(HashMap::new()),
+            virtual_stamps: Mutex::new(HashMap::new()),
             injections: injections::State::default(),
             notebooks: Mutex::new(HashMap::new()),
         })
@@ -1170,6 +1178,7 @@ impl LspManager {
             servers: servers.iter().map(|s| Attached { server: s.clone(), opened_gen: None }).collect(),
             compose_detected,
             notebook: None,
+            changed: std::time::Instant::now(),
         };
         let compose_added = {
             let mut docs = self.docs.lock();
@@ -1217,6 +1226,7 @@ impl LspManager {
         let mut docs = self.docs.lock();
         let Some(d) = docs.get_mut(&doc) else { return };
         d.version = version as i32;
+        d.changed = std::time::Instant::now();
 
         // Servers that have this document open on their current instance.
         let targets: Vec<(Arc<Server>, Running, SyncKind, Encoding)> = d
@@ -1392,6 +1402,7 @@ impl LspManager {
             language: d.language.clone(),
             text: d.text.clone(),
             servers,
+            changed: d.changed,
         })
     }
 
@@ -1433,13 +1444,9 @@ impl LspManager {
         let params = serde_json::to_value(params).map_err(|e| IdeError::internal(e.to_string()))?;
         let stamp = self.injected_request_stamp(&params);
         let fut = async {
-            if t.server.name == "csharp-ls" {
-                let mut value = t.run.peer.request::<Value, Value>(method, params, cancel.cloned()).await?;
-                virtual_doc::normalize_csharp_uris(&mut value);
-                serde_json::from_value(value).map_err(|e| RpcError::Protocol(format!("{method}: {e}")))
-            } else {
-                t.run.peer.request::<Value, R>(method, params, cancel.cloned()).await
-            }
+            let mut value = t.run.peer.request::<Value, Value>(method, params, cancel.cloned()).await?;
+            virtual_doc::normalize_uris(&mut value);
+            serde_json::from_value(value).map_err(|e| RpcError::Protocol(format!("{method}: {e}")))
         };
         let result = match tokio::time::timeout(timeout, fut).await {
             Ok(r) => r.map_err(|e| rpc_err(&t.server.name, method, e)),
@@ -3199,14 +3206,44 @@ impl LspManager {
         Ok(found)
     }
 
+    /// Whether the archive behind a cached library class changed since it was read.
+    /// Stats the archive: call from a blocking worker.
+    pub fn library_class_changed(&self, uri: &str) -> bool {
+        let Some(stamp) = self.virtual_stamps.lock().get(uri).copied() else { return false };
+        virtual_doc::archive_modified(uri) != Some(stamp)
+    }
+
+    /// Archives behind cached library classes that changed since they were read.
+    /// Stats each archive: call from a blocking worker.
+    pub fn changed_library_archives(&self) -> Vec<PathBuf> {
+        let uris: Vec<String> = self.virtual_stamps.lock().keys().cloned().collect();
+        let mut archives: Vec<PathBuf> = uris
+            .iter()
+            .filter(|uri| self.library_class_changed(uri))
+            .filter_map(|uri| virtual_doc::archive(uri))
+            .collect();
+        archives.sort();
+        archives.dedup();
+        archives
+    }
+
     /// Contents of a virtual document, from the server that owns `uri`:
     /// `workspace/textDocumentContent` (LSP 3.18) when the server serves the
     /// scheme, jdtls' `java/classFileContents` for `jdt:` URIs. A `jar:` entry
     /// is read from its archive, a `jar:` class shown as its library source
     /// (see [`library_source`]) or else decompiled by the server. Cached.
     pub async fn virtual_document(&self, uri: &str) -> IdeResult<VirtualDocument> {
-        if let Some(d) = self.virtual_docs.lock().get(uri) {
-            return Ok(d.clone());
+        let cached = self.virtual_docs.lock().get(uri).cloned();
+        if let Some(d) = cached {
+            let stamp = self.virtual_stamps.lock().get(uri).copied();
+            let current = {
+                let uri = uri.to_owned();
+                tokio::task::spawn_blocking(move || virtual_doc::archive_modified(&uri)).await.ok().flatten()
+            };
+            if stamp.is_none() || stamp == current {
+                return Ok(d);
+            }
+            self.virtual_docs.lock().remove(uri);
         }
         let scheme = virtual_doc::scheme(uri).to_owned();
         let jar_class = scheme == "jar" && library_source::parse(uri).is_some_and(|e| e.entry.ends_with(".class"));
@@ -3350,11 +3387,18 @@ impl LspManager {
         if let Some(server) = server {
             self.virtual_origins.lock().entry(uri.to_owned()).or_insert(server);
         }
+        let stamp = virtual_doc::archive_modified(uri);
         let mut cache = self.virtual_docs.lock();
+        let mut stamps = self.virtual_stamps.lock();
         if cache.len() >= VIRTUAL_CACHE_LIMIT {
             cache.clear();
+            stamps.clear();
         }
         cache.insert(uri.to_owned(), doc.clone());
+        match stamp {
+            Some(stamp) => stamps.insert(uri.to_owned(), stamp),
+            None => stamps.remove(uri),
+        };
         doc
     }
 

crates/ide-lsp/src/notebook.rs

@@ -213,6 +213,7 @@ impl LspManager {
             {
                 if d.text.as_str() != cell.source {
                     Arc::make_mut(&mut d.text).set(&cell.source);
+                    d.changed = std::time::Instant::now();
                 }
                 d.version += 1;
                 state.cells.push((cell.id.clone(), doc));
@@ -234,6 +235,7 @@ impl LspManager {
                     servers: state.servers.iter().map(|s| Attached { server: s.clone(), opened_gen: None }).collect(),
                     compose_detected: false,
                     notebook: Some(path.to_owned()),
+                    changed: std::time::Instant::now(),
                 },
             );
             state.cells.push((cell.id.clone(), doc));
@@ -259,6 +261,7 @@ impl LspManager {
             }
             Arc::make_mut(&mut d.text).set(&cell.source);
             d.version += 1;
+            d.changed = std::time::Instant::now();
             content.push(json!({
                 "document": { "uri": d.uri, "version": d.version },
                 "changes": [{ "text": cell.source }],

crates/ide-lsp/src/server.rs

@@ -445,8 +445,12 @@ impl Server {
             message.push_str(":\n");
             message.push_str(&tail);
         }
-        let delay = self.record_crash();
-        message.push_str(if delay.is_some() {
+        // Starting the same build again can't help: only an update can.
+        let expired = self.reported_expired_build();
+        let delay = if expired { None } else { self.record_crash() };
+        message.push_str(if expired {
+            "\nThis build has expired; update it to start it again."
+        } else if delay.is_some() {
             "\nRestarting…"
         } else {
             "\nCrashed repeatedly; restart it manually."
@@ -757,6 +761,12 @@ impl Server {
         crash_excerpt(&lines, n)
     }
 
+    /// JetBrains preview builds (kotlin-lsp) refuse to run past their expiry date and
+    /// exit with "This build of kotlin-server has expired".
+    fn reported_expired_build(&self) -> bool {
+        self.stderr.lock().iter().any(|l| is_expired_build_line(l))
+    }
+
     pub fn take_progress(&self) -> Vec<(TaskId, String)> {
         *self.loading.lock() = None;
         self.external_loading.store(0, std::sync::atomic::Ordering::Release);
@@ -770,6 +780,20 @@ impl Server {
         self.combine(path)
     }
 
+    /// [`Server::set_diagnostics`] for a publication tagged with a document version older than
+    /// the text the server has now: shown, but not an answer for the current text, so
+    /// [`Server::last_published`] keeps its time.
+    pub fn set_obsolete_diagnostics(&self, path: PathBuf, items: Vec<lsp::Diagnostic>) -> Vec<lsp::Diagnostic> {
+        let before = self.last_published(&path);
+        let shown = self.set_diagnostics(path.clone(), items);
+        let mut published = self.published.lock();
+        match before {
+            Some(at) => published.insert(path, at),
+            None => published.remove(&path),
+        };
+        shown
+    }
+
     /// Records a pulled report for `path` (`None` items: unchanged since `result_id`'s
     /// predecessor); returns what the file now shows.
     pub fn set_pulled(
@@ -897,6 +921,10 @@ fn is_error_headline(line: &str) -> bool {
     named || l.starts_with("Exception in thread") || l.starts_with("thread '") && l.contains("panicked")
 }
 
+fn is_expired_build_line(line: &str) -> bool {
+    line.contains("This build of ") && line.contains(" has expired")
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -1057,6 +1085,31 @@ mod tests {
         assert_eq!(waiter.await.unwrap(), (true, ServerStatus::Crashed));
     }
 
+    #[test]
+    fn an_expired_build_is_not_restarted() {
+        let sink: SharedSink = Arc::new(|_: IdeEvent| {});
+        let s = server();
+        let generation = s.begin_start().unwrap();
+        s.push_stderr(generation, "idea.system.path=/tmp/idea-system".into());
+        s.push_stderr(
+            generation,
+            "This build of kotlin-server has expired. The IDE will now close. Please download a new build".into(),
+        );
+        assert_eq!(s.on_closed(generation, &sink, Some(7)), Some(None));
+        assert_eq!(s.status(), ServerStatus::Crashed);
+        assert!(s.status_message().unwrap().ends_with("This build has expired; update it to start it again."));
+        assert!(matches!(s.state.lock().conn, Conn::Failed));
+        // A manual restart (after an update) starts it again.
+        s.reset_for_restart();
+        assert!(s.begin_start().is_some());
+
+        // Any other crash is restarted.
+        let s = server();
+        let generation = s.begin_start().unwrap();
+        s.push_stderr(generation, "Exception in thread main".into());
+        assert_eq!(s.on_closed(generation, &sink, Some(1)), Some(Some(Duration::from_millis(500))));
+    }
+
     #[test]
     fn a_superseded_start_is_not_announced() {
         let s = server();

crates/ide-lsp/src/uri.rs

@@ -1,6 +1,8 @@
 //! `file://` URI ⇄ path conversion (RFC 8089, VS Code-compatible encoding).
 
 use percent_encoding::{AsciiSet, CONTROLS, percent_decode_str, utf8_percent_encode};
+use serde_json::Value;
+use std::borrow::Cow;
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
 
@@ -22,6 +24,53 @@ const PATH: &AsciiSet = &CONTROLS
     .add(b'|')
     .add(b'}');
 
+/// What RFC 3986 doesn't allow in a URI and a server may still leave unencoded in a `file:`
+/// URI (non-ASCII is always encoded); `%` stays, it starts the escapes already there.
+const LOOSE: &AsciiSet = &CONTROLS
+    .add(b' ')
+    .add(b'"')
+    .add(b'<')
+    .add(b'>')
+    .add(b'[')
+    .add(b'\\')
+    .add(b']')
+    .add(b'^')
+    .add(b'`')
+    .add(b'{')
+    .add(b'|')
+    .add(b'}');
+
+/// Percent-encodes the characters URIs don't allow in every `file:` URI in `value`, string
+/// values and object keys alike (a workspace edit's `changes`). Eclipse's jdtls sends a path
+/// as is (`file:///H:/项目/…`), which `lsp_types::Uri` rejects, failing the whole response.
+pub fn encode_loose_file_uris(value: &mut Value) {
+    match value {
+        Value::String(s) => {
+            if let Some(encoded) = encode_loose(s) {
+                *s = encoded;
+            }
+        }
+        Value::Array(items) => items.iter_mut().for_each(encode_loose_file_uris),
+        Value::Object(map) => {
+            if map.keys().any(|k| encode_loose(k).is_some()) {
+                *map = std::mem::take(map).into_iter().map(|(k, v)| (encode_loose(&k).unwrap_or(k), v)).collect();
+            }
+            map.values_mut().for_each(encode_loose_file_uris);
+        }
+        _ => {}
+    }
+}
+
+fn encode_loose(s: &str) -> Option<String> {
+    if !s.get(..5).is_some_and(|scheme| scheme.eq_ignore_ascii_case("file:")) {
+        return None;
+    }
+    match Cow::from(utf8_percent_encode(s, LOOSE)) {
+        Cow::Owned(encoded) => Some(encoded),
+        Cow::Borrowed(_) => None,
+    }
+}
+
 pub fn path_to_uri_string(path: &Path) -> String {
     let s = if cfg!(windows) {
         dunce::simplified(path).to_string_lossy().replace('\\', "/")
@@ -95,6 +144,28 @@ pub use ide_core::text::is_virtual_uri;
 mod tests {
     use super::*;
 
+    #[test]
+    fn file_uris_a_server_leaves_unencoded_are_encoded() {
+        // jdtls on a project under a Chinese folder (`java.usages` / references response).
+        let mut v = serde_json::json!({ "result": [{
+            "location": { "uri": "file:///H:/项目/online disk/A.java", "range": { "start": { "line": 1, "character": 2 }, "end": { "line": 1, "character": 3 } } },
+            "kind": "unknown"
+        }], "edit": { "changes": { "file:///tmp/目录/b.java": [] } }, "text": "项目" });
+        let raw = v["result"][0]["location"].clone();
+        assert!(serde_json::from_value::<lsp_types::Location>(raw).is_err(), "lsp-types rejects it as sent");
+        encode_loose_file_uris(&mut v);
+        let uri = v["result"][0]["location"]["uri"].as_str().unwrap();
+        assert_eq!(uri, "file:///H:/%E9%A1%B9%E7%9B%AE/online%20disk/A.java");
+        let location: lsp_types::Location = serde_json::from_value(v["result"][0]["location"].clone()).unwrap();
+        assert!(uri_to_path(location.uri.as_str()).unwrap().ends_with("项目/online disk/A.java"));
+        assert!(v["edit"]["changes"].get("file:///tmp/%E7%9B%AE%E5%BD%95/b.java").is_some());
+        assert_eq!(v["text"], "项目", "only file: URIs change");
+        // Already encoded: untouched.
+        let mut encoded = serde_json::json!("file:///a%20b/%E9%A1%B9.java");
+        encode_loose_file_uris(&mut encoded);
+        assert_eq!(encoded, "file:///a%20b/%E9%A1%B9.java");
+    }
+
     #[cfg(unix)]
     #[test]
     fn round_trip() {

crates/ide-lsp/src/virtual_doc.rs

@@ -18,23 +18,36 @@ const URI_ESCAPES: &AsciiSet = &CONTROLS
     .add(b'|')
     .add(b'}');
 
-/// csharp-ls uses .NET Uri.ToString(), which can leave spaces and Unicode unescaped.
-/// Normalize only document URI fields, before lsp-types' strict URI deserialization.
-pub(crate) fn normalize_csharp_uris(value: &mut serde_json::Value) {
+/// Servers can leave spaces and Unicode unescaped in document URIs: csharp-ls uses .NET
+/// `Uri.ToString()`, and Java servers build some URIs with `java.net.URI.toString()` (which keeps
+/// non-ASCII characters), e.g. jdtls in a refactoring's edit for a project under a Chinese path.
+/// Escape them in document URI fields (and `WorkspaceEdit.changes` keys) before lsp-types' strict
+/// URI deserialization, which otherwise rejects the whole response.
+pub(crate) fn normalize_uris(value: &mut serde_json::Value) {
     match value {
-        serde_json::Value::Array(values) => values.iter_mut().for_each(normalize_csharp_uris),
+        serde_json::Value::Array(values) => values.iter_mut().for_each(normalize_uris),
         serde_json::Value::Object(fields) => {
-            for (key, value) in fields {
+            for (key, value) in fields.iter_mut() {
                 // Opaque payloads must survive resolve/execute round trips unchanged.
                 if matches!(key.as_str(), "data" | "arguments") {
                     continue;
                 }
-                if matches!(key.as_str(), "uri" | "targetUri")
-                    && let Some(uri) = value.as_str().filter(|s| s.starts_with("csharp:"))
+                if matches!(key.as_str(), "uri" | "targetUri" | "oldUri" | "newUri")
+                    && let Some(uri) = value.as_str().and_then(escaped_uri)
                 {
-                    *value = utf8_percent_encode(uri, URI_ESCAPES).to_string().into();
+                    *value = uri.into();
+                } else if key == "changes"
+                    && let serde_json::Value::Object(changes) = value
+                {
+                    *changes = std::mem::take(changes)
+                        .into_iter()
+                        .map(|(uri, mut edits)| {
+                            normalize_uris(&mut edits);
+                            (escaped_uri(&uri).unwrap_or(uri), edits)
+                        })
+                        .collect();
                 } else {
-                    normalize_csharp_uris(value);
+                    normalize_uris(value);
                 }
             }
         }
@@ -42,6 +55,16 @@ pub(crate) fn normalize_csharp_uris(value: &mut serde_json::Value) {
     }
 }
 
+/// `uri` with the characters a URI can't hold escaped; `None` when nothing changes or it is
+/// not a document URI this applies to (other schemes are passed back to servers as given).
+fn escaped_uri(uri: &str) -> Option<String> {
+    if !(uri.starts_with("file:") || uri.starts_with("csharp:")) {
+        return None;
+    }
+    let escaped = utf8_percent_encode(uri, URI_ESCAPES).to_string();
+    (escaped != uri).then_some(escaped)
+}
+
 #[derive(serde::Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub(crate) struct CSharpMetadata {
@@ -149,6 +172,20 @@ pub fn description(uri: &str) -> Option<String> {
     }
 }
 
+/// The archive a `jar:` or `jdt:` library class comes from.
+pub(crate) fn archive(uri: &str) -> Option<std::path::PathBuf> {
+    match scheme(uri) {
+        "jar" => Some(crate::library_source::parse(uri)?.jar),
+        "jdt" => description(uri).filter(|p| p.ends_with(".jar") || p.ends_with(".jmod")).map(Into::into),
+        _ => None,
+    }
+}
+
+/// Modification time of the archive a `jar:` or `jdt:` library class comes from.
+pub(crate) fn archive_modified(uri: &str) -> Option<std::time::SystemTime> {
+    std::fs::metadata(archive(uri)?).and_then(|m| m.modified()).ok()
+}
+
 /// 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);
@@ -202,7 +239,7 @@ mod tests {
             { "data": { "uri": uri }, "command": { "arguments": [{ "targetUri": uri }] } }
         ]);
         let original = response.clone();
-        normalize_csharp_uris(&mut response);
+        normalize_uris(&mut response);
         assert_eq!(response[0]["uri"], encoded);
         assert_eq!(response[0]["source"], uri);
         assert_eq!(response[1]["location"]["targetUri"], encoded);
@@ -210,6 +247,31 @@ mod tests {
         assert!(encoded.parse::<lsp_types::Uri>().is_ok());
     }
 
+    /// #3089: jdtls's Introduce Variable edit for a project under a Chinese path names the file
+    /// with the characters unescaped, and the resolved code action failed to deserialize.
+    #[test]
+    fn file_uris_with_unicode_and_spaces_deserialize_in_workspace_edits() {
+        let uri = "file:///C:/项目/my app/src/A.java";
+        let encoded = "file:///C:/%E9%A1%B9%E7%9B%AE/my%20app/src/A.java";
+        let edit = serde_json::json!([{ "range": { "start": { "line": 0, "character": 0 }, "end": { "line": 0, "character": 0 } }, "newText": "x" }]);
+        let mut action = serde_json::json!({
+            "title": "Extract to local variable",
+            "edit": {
+                "documentChanges": [{ "textDocument": { "uri": uri, "version": 3 }, "edits": edit }],
+                "changes": { (uri): edit },
+            },
+            "data": { "uri": uri },
+        });
+        assert!(serde_json::from_value::<lsp_types::CodeAction>(action.clone()).is_err());
+        normalize_uris(&mut action);
+        let action: lsp_types::CodeAction = serde_json::from_value(action.clone()).unwrap();
+        let edit = action.edit.unwrap();
+        let Some(lsp_types::DocumentChanges::Edits(edits)) = edit.document_changes else { panic!() };
+        assert_eq!(edits[0].text_document.uri.as_str(), encoded);
+        assert_eq!(edit.changes.unwrap().keys().next().unwrap().as_str(), encoded);
+        assert_eq!(action.data.unwrap()["uri"], uri, "opaque data is passed back unchanged");
+    }
+
     #[test]
     fn jdt_titles() {
         assert_eq!(title(JDT, true), "SpringApplication.class");
@@ -256,6 +318,29 @@ mod tests {
         assert_eq!(description("foo://x/y"), None);
     }
 
+    #[test]
+    fn finds_the_archive_behind_a_library_class() {
+        assert_eq!(archive(JDT), Some("/Users/me/.m2/repository/spring-boot-4.1.1.jar".into()));
+        assert_eq!(
+            archive("jdt://contents/java.base/java.lang/String.class?=p/%5C/jdk%5C/lib%5C/jrt-fs.jar%60java.base=x"),
+            None
+        );
+        assert_eq!(archive("jdt://contents/a.jar/p/C.class"), None);
+        assert_eq!(archive("file:///a/C.java"), None);
+
+        let dir = tempfile::tempdir().unwrap();
+        let jar = dir.path().join("lib-1.0-SNAPSHOT.jar");
+        std::fs::write(&jar, b"PK").unwrap();
+        let uri = format!("jar:file://{}!/p/C.class", jar.display());
+        assert_eq!(archive(&uri), Some(jar.clone()));
+        let before = archive_modified(&uri).unwrap();
+        let file = std::fs::File::options().write(true).open(&jar).unwrap();
+        file.set_modified(before + std::time::Duration::from_secs(5)).unwrap();
+        assert_ne!(archive_modified(&uri), Some(before));
+        std::fs::remove_file(&jar).unwrap();
+        assert_eq!(archive_modified(&uri), None);
+    }
+
     #[test]
     fn detects_generated_code() {
         assert!(is_decompiled(

crates/ide-lsp/tests/mock_server.rs

@@ -2204,6 +2204,25 @@ async fn checking_a_document_saves_it_and_waits_for_fresh_diagnostics() {
     let stale = h.mgr.check_document(doc, changed, Duration::from_millis(800), &cancel).await.unwrap();
     assert!(stale.servers[0].checked && stale.servers[0].incomplete, "{:?}", stale.servers);
     assert_eq!(stale.diagnostics.len(), 1);
+
+    // The text changed before the call (the file watcher reloaded it), so the caller saw no
+    // change of its own: the old publication is still not fresh.
+    h.mgr.did_change(doc, 2, &[change(rng(0, 0, 0, 3), "good")], &|| "good\n".to_owned());
+    let reloaded = h.mgr.check_document(doc, None, Duration::from_millis(800), &cancel).await.unwrap();
+    assert!(reloaded.servers[0].incomplete, "{:?}", reloaded.servers);
+
+    // A late publication tagged with the old version is no answer for the current text.
+    s.peer()
+        .notify("textDocument/publishDiagnostics", json!({ "uri": uri_of(&path), "version": 1, "diagnostics": [] }))
+        .unwrap();
+    let late = h.mgr.check_document(doc, None, Duration::from_millis(800), &cancel).await.unwrap();
+    assert!(late.servers[0].incomplete, "{:?}", late.servers);
+    // One for the current version is.
+    s.peer()
+        .notify("textDocument/publishDiagnostics", json!({ "uri": uri_of(&path), "version": 2, "diagnostics": [] }))
+        .unwrap();
+    let fresh = h.mgr.check_document(doc, None, Duration::from_secs(5), &cancel).await.unwrap();
+    assert!(fresh.servers[0].checked && !fresh.servers[0].incomplete, "{:?}", fresh.servers);
 }
 
 #[tokio::test(flavor = "multi_thread")]

crates/ide-mcp/src/discovery.rs

@@ -1,6 +1,7 @@
 //! `<app-data>/mcp/server.json`: where the running IDE's server listens and
 //! its token, for the stdio bridge. Readable only by the user; removed when
-//! the server stops.
+//! the server stops. `<app-data>/mcp/token` keeps the token across runs when
+//! the user chose a fixed token.
 
 use serde::{Deserialize, Serialize};
 use std::io;
@@ -14,6 +15,28 @@ pub fn discovery_path(app_data: &Path) -> PathBuf {
     app_data.join(DISCOVERY_FILE)
 }
 
+/// The kept token, relative to the app data directory.
+pub const TOKEN_FILE: &str = "mcp/token";
+
+/// The kept token of the IDE whose app data directory is `app_data`.
+pub fn token_path(app_data: &Path) -> PathBuf {
+    app_data.join(TOKEN_FILE)
+}
+
+/// The token kept at `path`; a new one is made and kept there when there is none (or the
+/// file doesn't hold one). Readable only by the user.
+pub fn kept_token(path: &Path) -> io::Result<String> {
+    if let Ok(text) = std::fs::read_to_string(path) {
+        let token = text.trim();
+        if token.len() == 64 && token.bytes().all(|b| b.is_ascii_hexdigit()) {
+            return Ok(token.to_owned());
+        }
+    }
+    let token = crate::server::new_token()?;
+    write_atomic(path, token.as_bytes())?;
+    Ok(token)
+}
+
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Discovery {
     pub port: u16,
@@ -32,15 +55,8 @@ impl Discovery {
 
     /// Writes the file atomically, readable only by the user.
     pub fn write(&self, path: &Path) -> io::Result<()> {
-        let dir = path.parent().ok_or_else(|| io::Error::other("no parent directory"))?;
-        std::fs::create_dir_all(dir)?;
-        let tmp = path.with_extension(format!("tmp{}", std::process::id()));
         let bytes = serde_json::to_vec_pretty(self).map_err(io::Error::other)?;
-        let written = write_private(&tmp, &bytes).and_then(|()| std::fs::rename(&tmp, path));
-        if written.is_err() {
-            let _ = std::fs::remove_file(&tmp);
-        }
-        written
+        write_atomic(path, &bytes)
     }
 
     /// Removes the file at `path` if it still describes this process's server.
@@ -51,6 +67,18 @@ impl Discovery {
     }
 }
 
+/// Writes `bytes` to `path` atomically, readable only by the user.
+fn write_atomic(path: &Path, bytes: &[u8]) -> io::Result<()> {
+    let dir = path.parent().ok_or_else(|| io::Error::other("no parent directory"))?;
+    std::fs::create_dir_all(dir)?;
+    let tmp = path.with_extension(format!("tmp{}", std::process::id()));
+    let written = write_private(&tmp, bytes).and_then(|()| std::fs::rename(&tmp, path));
+    if written.is_err() {
+        let _ = std::fs::remove_file(&tmp);
+    }
+    written
+}
+
 #[cfg(unix)]
 fn write_private(path: &Path, bytes: &[u8]) -> io::Result<()> {
     use std::io::Write;
@@ -91,4 +119,23 @@ mod tests {
         Discovery::remove_if_ours(&path);
         assert!(!path.exists());
     }
+
+    #[test]
+    fn keeps_one_token_until_its_file_is_removed() {
+        let tmp = tempfile::tempdir().unwrap();
+        let path = token_path(tmp.path());
+        let first = kept_token(&path).unwrap();
+        assert_eq!(first.len(), 64);
+        assert_eq!(kept_token(&path).unwrap(), first, "the same token on the next run");
+        #[cfg(unix)]
+        {
+            use std::os::unix::fs::PermissionsExt;
+            assert_eq!(std::fs::metadata(&path).unwrap().permissions().mode() & 0o777, 0o600);
+        }
+        std::fs::write(&path, "not a token").unwrap();
+        let replaced = kept_token(&path).unwrap();
+        assert_ne!(replaced, first);
+        std::fs::remove_file(&path).unwrap();
+        assert_ne!(kept_token(&path).unwrap(), replaced, "a removed token is made anew");
+    }
 }

crates/ide-mcp/src/lib.rs

@@ -22,8 +22,8 @@ mod protocol;
 mod server;
 pub mod stdio;
 
-pub use discovery::{DISCOVERY_FILE, Discovery, discovery_path};
-pub use server::McpServer;
+pub use discovery::{DISCOVERY_FILE, Discovery, TOKEN_FILE, discovery_path, kept_token, token_path};
+pub use server::{McpServer, ServerOptions};
 pub use tokio_util::sync::CancellationToken;
 
 use std::path::{Path, PathBuf};

crates/ide-mcp/src/server.rs

@@ -49,12 +49,25 @@ struct Shared {
 /// removes its discovery file.
 pub struct McpServer {
     port: u16,
+    /// Why the port asked for in [`ServerOptions::port`] was not used.
+    port_unavailable: Option<String>,
     token: String,
     discovery: Option<PathBuf>,
     shutdown: watch::Sender<bool>,
     cancel: CancellationToken,
 }
 
+/// How [`McpServer::start_with`] listens.
+#[derive(Clone, Debug, Default)]
+pub struct ServerOptions {
+    /// Listen on `127.0.0.1:<port>`. When it can't be bound (in use, or reserved by the
+    /// system), a free port is taken instead and [`McpServer::port_unavailable`] says why.
+    /// `None`: a free port.
+    pub port: Option<u16>,
+    /// The bearer token; `None`: a new one.
+    pub token: Option<String>,
+}
+
 impl McpServer {
     /// Starts listening on `127.0.0.1:<random port>` with a new token, on
     /// `runtime`, and writes the discovery file at `discovery` if given.
@@ -63,10 +76,32 @@ impl McpServer {
         discovery: Option<PathBuf>,
         runtime: &tokio::runtime::Handle,
     ) -> std::io::Result<Self> {
-        let listener = std::net::TcpListener::bind(("127.0.0.1", 0))?;
+        Self::start_with(registry, discovery, runtime, ServerOptions::default())
+    }
+
+    /// [`Self::start`] on the port and with the token of `options`.
+    pub fn start_with(
+        registry: Arc<dyn ToolRegistry>,
+        discovery: Option<PathBuf>,
+        runtime: &tokio::runtime::Handle,
+        options: ServerOptions,
+    ) -> std::io::Result<Self> {
+        let (listener, port_unavailable) = match options.port {
+            Some(port) => match std::net::TcpListener::bind(("127.0.0.1", port)) {
+                Ok(listener) => (listener, None),
+                Err(e) => {
+                    tracing::warn!("MCP server: port {port} unavailable ({e}); taking a free one");
+                    (std::net::TcpListener::bind(("127.0.0.1", 0))?, Some(format!("port {port}: {e}")))
+                }
+            },
+            None => (std::net::TcpListener::bind(("127.0.0.1", 0))?, None),
+        };
         listener.set_nonblocking(true)?;
         let port = listener.local_addr()?.port();
-        let token = new_token()?;
+        let token = match options.token {
+            Some(token) => token,
+            None => new_token()?,
+        };
         let listener = {
             let _entered = runtime.enter();
             tokio::net::TcpListener::from_std(listener)?
@@ -91,13 +126,18 @@ impl McpServer {
         });
         runtime.spawn(accept(listener, shared, stopped));
         tracing::info!("MCP server on 127.0.0.1:{port}");
-        Ok(Self { port, token, discovery, shutdown, cancel })
+        Ok(Self { port, port_unavailable, token, discovery, shutdown, cancel })
     }
 
     pub fn port(&self) -> u16 {
         self.port
     }
 
+    /// Why the port of [`ServerOptions::port`] is not the one listened on.
+    pub fn port_unavailable(&self) -> Option<&str> {
+        self.port_unavailable.as_deref()
+    }
+
     /// The bearer token of this run.
     pub fn token(&self) -> &str {
         &self.token

crates/ide-mcp/tests/server.rs

@@ -1,7 +1,7 @@
 //! The server over real HTTP, and the stdio bridge in front of it, with a
 //! registry standing in for the IDE host.
 
-use ide_mcp::{Discovery, McpServer, Tool, ToolCallError, ToolRegistry, discovery_path, stdio};
+use ide_mcp::{Discovery, McpServer, ServerOptions, Tool, ToolCallError, ToolRegistry, discovery_path, stdio};
 use serde_json::{Value, json};
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
@@ -366,3 +366,30 @@ async fn a_cancellation_that_arrives_before_the_call_is_remembered() {
     let (_, body) = post(&s, "/mcp", &headers, &call).await;
     assert_eq!(serde_json::from_str::<Value>(&body).unwrap()["result"]["isError"], true);
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn a_fixed_port_and_token_are_used_and_a_taken_port_falls_back_to_a_free_one() {
+    let mut s = setup();
+    s.server.take().unwrap().stop();
+    let free = std::net::TcpListener::bind(("127.0.0.1", 0)).unwrap().local_addr().unwrap().port();
+    let token = "ab".repeat(32);
+    let options = ServerOptions { port: Some(free), token: Some(token.clone()) };
+    let registry = Arc::new(Registry { project: s.project.clone() });
+    let runtime = tokio::runtime::Handle::current();
+    s.server =
+        Some(McpServer::start_with(registry.clone(), Some(s.discovery.clone()), &runtime, options.clone()).unwrap());
+    assert_eq!((s.server().port(), s.server().token()), (free, token.as_str()));
+    assert!(s.server().port_unavailable().is_none());
+    assert_eq!(Discovery::read(&s.discovery).unwrap().port, free);
+    let list = rpc(&s, "tools/list", json!({})).await;
+    assert_eq!(list["result"]["tools"][0]["name"], "echo");
+
+    // The port is taken (by the first server): a second one listens elsewhere and says why.
+    let second = McpServer::start_with(registry, None, &runtime, options).unwrap();
+    assert_ne!(second.port(), free);
+    assert!(
+        second.port_unavailable().is_some_and(|why| why.contains(&free.to_string())),
+        "{:?}",
+        second.port_unavailable()
+    );
+}

crates/ide-plugin/src/runtime.rs

@@ -55,7 +55,7 @@ use views_bindings::exports::openidea::plugin::view_provider as wit_view;
 use views_bindings::openidea::plugin::view_types as wit_vt;
 
 /// The API version of the world above, `major.minor` of [`host_api`].
-pub const API_VERSION: &str = "1.7";
+pub const API_VERSION: &str = "1.8";
 const EPOCH_TICK: Duration = Duration::from_millis(10);
 pub(crate) const MAX_TEXT: usize = 1 << 20;
 pub(crate) const MAX_TITLE: usize = 256;
@@ -1058,6 +1058,9 @@ fn event_to_wit(e: WorkbenchEvent) -> wit_events::Event {
         }),
         WorkbenchEvent::EditorFocused(p) => wit_events::Event::EditorFocused(p),
         WorkbenchEvent::VcsChanged(p) => wit_events::Event::VcsChanged(p),
+        WorkbenchEvent::ProblemsChanged => {
+            wit_events::Event::Other(wit_types::Extension { kind: "problems-changed".into(), data: "{}".into() })
+        }
         WorkbenchEvent::Scheduled => wit_events::Event::Scheduled,
         WorkbenchEvent::ActionPerformed(a) => wit_events::Event::ActionPerformed(wit_events::ActionPerformed {
             action: a.action,

crates/ide-plugin/src/types.rs

@@ -119,11 +119,13 @@ pub enum EventKind {
     EditorFocused,
     ActionPerformed,
     VcsChanged,
+    /// Problems of the window's files changed (a language server or a report).
+    ProblemsChanged,
     Scheduled,
 }
 
 impl EventKind {
-    pub const ALL: [Self; 16] = [
+    pub const ALL: [Self; 17] = [
         Self::DocumentChanged,
         Self::WebsocketReady,
         Self::FileClosed,
@@ -139,6 +141,7 @@ impl EventKind {
         Self::EditorFocused,
         Self::ActionPerformed,
         Self::VcsChanged,
+        Self::ProblemsChanged,
         Self::Scheduled,
     ];
 
@@ -159,6 +162,7 @@ impl EventKind {
             Self::EditorFocused => "editor-focused",
             Self::ActionPerformed => "action-performed",
             Self::VcsChanged => "vcs-changed",
+            Self::ProblemsChanged => "problems-changed",
             Self::Scheduled => "scheduled",
         }
     }
@@ -294,6 +298,8 @@ pub enum WorkbenchEvent {
     EditorFocused(Option<String>),
     ActionPerformed(ActionPerformed),
     VcsChanged(String),
+    /// Problems of the window's files changed; plugins re-read `problems`.
+    ProblemsChanged,
     Scheduled,
 }
 
@@ -315,6 +321,7 @@ impl WorkbenchEvent {
             Self::EditorFocused(_) => EventKind::EditorFocused,
             Self::ActionPerformed(_) => EventKind::ActionPerformed,
             Self::VcsChanged(_) => EventKind::VcsChanged,
+            Self::ProblemsChanged => EventKind::ProblemsChanged,
             Self::Scheduled => EventKind::Scheduled,
         }
     }

crates/ide-plugin/tests/api_compat.rs

@@ -91,15 +91,15 @@ fn the_sdk_carries_the_hosts_wit() {
 
 #[test]
 fn the_version_check_runs_compatible_components_and_explains_the_rest() {
-    let host = v("1.7.0");
-    for ok in ["1.0.0", "1.3.0", "1.4.7", "1.5.0", "1.6.0", "1.7.0", "1.0.0-rc.1"] {
+    let host = v("1.8.0");
+    for ok in ["1.0.0", "1.3.0", "1.4.7", "1.5.0", "1.6.0", "1.7.0", "1.8.0", "1.0.0-rc.1"] {
         assert_eq!(check_api(&v(ok), &host), Ok(()), "{ok}");
     }
-    let newer = check_api(&v("1.8.0"), &host).unwrap_err();
-    assert!(newer.contains("1.8") && newer.contains("update OpenIDEA"), "{newer}");
+    let newer = check_api(&v("1.9.0"), &host).unwrap_err();
+    assert!(newer.contains("1.9") && newer.contains("update OpenIDEA"), "{newer}");
     assert!(check_api(&v("2.0.0"), &host).unwrap_err().contains("update OpenIDEA"));
     let older = check_api(&v("0.2.0"), &host).unwrap_err();
-    assert!(older.contains("rebuild it with the 1.7 SDK"), "{older}");
+    assert!(older.contains("rebuild it with the 1.8 SDK"), "{older}");
     // 0.x: every minor is its own API.
     assert_eq!(check_api(&v("0.2.0"), &v("0.2.5")), Ok(()));
     assert!(check_api(&v("0.1.0"), &v("0.2.0")).is_err());

crates/ide-plugin/tests/fixtures/api14/dist/plugin.wasm.sources

@@ -1 +1 @@
-d6c855f1f91aeb02eec5d6c8a07be4eb64bae0704619f44cb67f3b832daf01ee
+6c50332c868a890b91a7f92ef7f92e76a4818b7435291e99c77c0b9f0931b81c

crates/ide-plugin/tests/fixtures/commit/dist/plugin.wasm.sources

@@ -1 +1 @@
-51d00702c42c7167083caea70cf2df022e512bcaf89af8addf526421ff45a15f
+fdcb208365db90bcd06d0d0df3d436b69d1229c40f7c63dd6f1ab768e0d236b8

crates/ide-plugin/tests/fixtures/data-tools/dist/plugin.wasm.sources

@@ -1 +1 @@
-40d2fd76ba96b0c93ea0a034c6749709ddc00fc119046e653a50b180a9c4718d
+3108abe8d381b224ec4b44ecf4c43c045671bd5e221ee21582e25497f8c14dff

crates/ide-plugin/tests/fixtures/detail-views/dist/plugin.wasm.sources

@@ -1 +1 @@
-08822287f3649412340f9dbbe2f0ea5a5cd2f543a3c242c5d0a29c422c4c5367
+876a84b7da5a4b27fce47cf71a4dc28eb1ea6c9d54283c1b73a2ae2411653bf5

crates/ide-plugin/tests/fixtures/diagnostics/dist/plugin.wasm.sources

@@ -1 +1 @@
-43eba23cc14cf3c74bfc934099cd58df20f07ee5df96cc10100b90016c544a7a
+234dc693e01e484b91fa7f2d0ac0e7757fb69c9fba81f06bf8ef1cd3624228d8

crates/ide-plugin/tests/fixtures/diagnostics/src/lib.rs

@@ -21,6 +21,31 @@ impl Plugin for Fixture {
                 &[Diagnostic::new(Range::default(), Severity::Info, "Manual problem")],
             )
             .map(|()| None),
+            // The host-owned snapshot, one entry per producer: what `problems` reads.
+            "problems" => {
+                let files: Vec<String> = host::problems(None)?
+                    .into_iter()
+                    .map(|f| format!("{}:{}:{}", f.path, f.source, f.diagnostics.len()))
+                    .collect();
+                Ok(Some(files.join("|")))
+            }
+            // A line-end annotation in the severity styles the editor draws: the host must
+            // keep `typo` and `weak` instead of dropping them as unknown.
+            "decorate" => {
+                let path = arg.unwrap_or_default();
+                let item = |style: &str, after: &str| openidea_plugin::Decoration {
+                    range: Range::default(),
+                    style: style.into(),
+                    hover: None,
+                    after: Some(after.into()),
+                };
+                host::set_decorations(
+                    path,
+                    "fixture",
+                    &[item("typo", "typo message"), item("weak", "weak message")],
+                )
+                .map(|()| None)
+            }
             _ => Err(Error::NotFound(id.into())),
         }
     }

crates/ide-plugin/tests/fixtures/endpoints/dist/plugin.wasm.sources

@@ -1 +1 @@
-520d9a95328dc772bbb913a2e5e22af8243c95ca45744cbb65b25747653d2a34
+927c329fd21d12fd5f423b937e1be756be45a4c6dceee08679e762d5d9f511f2

crates/ide-plugin/tests/fixtures/execution/dist/plugin.wasm.sources

@@ -1 +1 @@
-acd3d0ee3f886c6a271ce3139200ce5bdb46e40f9c68e495c5ff9b4db98a88ac
+e7c77fde915e0765f91929dba2aa8eff606f2302e078b7305d272a4de5b9d80b

crates/ide-plugin/tests/fixtures/ext-owner/dist/plugin.wasm.sources

@@ -1 +1 @@
-0cf3bc2197f0bd5339fe3c2199bd973e68b3637b8c5ae07902e62659160275e3
+3feb9df8b408dedbc3586864db00b92c8cb244c8ad5b8f10c95edb8eb3d30df1

crates/ide-plugin/tests/fixtures/file-templates/dist/plugin.wasm.sources

@@ -1 +1 @@
-17f837c8d6f58800728e00060afe68b2a093085d816d809c9e67065fdd165352
+3bfce29f90b9d2f20082b9bdd0957c6c58c265a346305ec948f514537a4579c8

crates/ide-plugin/tests/fixtures/files-events/dist/plugin.wasm.sources

@@ -1 +1 @@
-2cca80220fab6764a8e1f51db8ed2f55b603000c8d0dbf5913a441876b7857ba
+ca72c5cfa2f76a93bc07495d50e58181a9c6c2fc75854cf548bb0278814ddb87