Merge pull request #6834 from Guan0923/codex/fix-python-output-encoding

fix(tui): preserve UTF-8 Python output on Windows

crates/tui/src/core/engine/tool_catalog.rs

@@ -1634,6 +1634,8 @@ pub(super) async fn execute_code_execution_tool(
     let budget = Duration::from_secs(120);
     let mut cmd =
         crate::tools::shell::sandboxed_runner_command(context, &program, args, workspace, budget)?;
+    // Match the UTF-8 decoder below, including Windows Python's piped output.
+    cmd.env("PYTHONIOENCODING", "utf-8");
     let output = tokio::time::timeout(
         budget,
         crate::process_tree::contained_output_with_input(&mut cmd, code.as_bytes().to_vec()),

crates/tui/src/core/engine/tool_catalog/tests.rs

@@ -34,6 +34,35 @@ fn code_execution_description_does_not_claim_process_sandboxing() {
     assert!(!CODE_EXECUTION_DESCRIPTION.contains("sandbox"));
 }
 
+/// Python output must match our UTF-8 decoder even with non-UTF-8 parent stdio.
+#[tokio::test]
+async fn code_execution_returns_utf8_stdout_and_stderr() {
+    use crate::dependencies::ExternalTool as _;
+    use crate::test_support::{EnvVarGuard, lock_test_env};
+
+    let _env_lock = lock_test_env();
+    if !crate::dependencies::Python::available() {
+        return;
+    }
+    let _encoding = EnvVarGuard::set("PYTHONIOENCODING", "gbk");
+    let tmp = tempfile::tempdir().expect("tempdir");
+    let result = super::execute_code_execution_tool(
+        &json!({"code": r#"import sys; print("\u4e2d\u6587"); print("\u9519\u8bef", file=sys.stderr)"#}),
+        tmp.path(),
+        &crate::tools::spec::ToolContext::new(tmp.path()),
+    )
+    .await
+    .expect("code execution should run");
+    let payload = result.metadata.expect("payload");
+    assert_eq!(
+        (
+            payload["stdout"].as_str().map(str::trim_end),
+            payload["stderr"].as_str().map(str::trim_end),
+        ),
+        (Some("中文"), Some("错误")),
+    );
+}
+
 /// The published synthetic-name list and the predicate that classifies a
 /// catalog entry as synthetic must agree. A name that appears in the list
 /// but is not classified synthetic would let the request projection report