merge PR #5671 via eval/pr-5671: fix(bash): drained piped output before timeout return

packages/coding-agent/src/exec/bash-executor.ts

@@ -70,6 +70,9 @@ const shellSessionsInUse = new Set<string>();
  */
 const retainedShells = new Set<Shell>();
 const RETAIN_REAP_INTERVAL_MS = 5_000;
+// Native cancellation may spend two seconds unwinding the shell before its
+// N-API chunk bridge drains. The JS watchdog must not race that teardown.
+const NATIVE_TIMEOUT_FALLBACK_GRACE_MS = 5_000;
 
 async function retainShellWithLiveBackgroundJobs(shell: Shell): Promise<void> {
 	let live: number;
@@ -306,16 +309,18 @@ export async function executeBash(command: string, options?: BashExecutorOptions
 	const nativeTimeoutMs = requestedTimeoutMs !== undefined && requestedTimeoutMs > 0 ? requestedTimeoutMs : undefined;
 	const nativeOwnsTimeout = nativeTimeoutMs !== undefined;
 	if (deadlineTimeoutMs !== undefined) {
+		const fallbackTimeoutMs = nativeOwnsTimeout
+			? deadlineTimeoutMs + NATIVE_TIMEOUT_FALLBACK_GRACE_MS
+			: deadlineTimeoutMs;
 		timeoutTimer = setTimeout(() => {
-			// Explicit timeouts are already enforced inside pi-natives via
-			// `timeoutMs`. Do not also abort the JS AbortSignal here: on Windows,
-			// aborting that signal while a piped command is still forwarding output
-			// can terminate the Bun host before the native timeout result resolves.
+			// Explicit timeouts are enforced inside pi-natives via `timeoutMs`.
+			// Give native cancellation time to flush pipeline output and drain the
+			// N-API bridge before this result-only watchdog quarantines the run.
 			if (!nativeOwnsTimeout) {
 				abortCurrentExecution();
 			}
 			timeoutDeferred.resolve("timeout");
-		}, deadlineTimeoutMs);
+		}, fallbackTimeoutMs);
 	}
 
 	let resetSession = false;