From ade6340a22bebb45b92fb0cffebd767f6fb9dbda Mon Sep 17 00:00:00 2001
From: Megan Rogge <merogge@microsoft.com>
Date: Wed, 29 Apr 2026 16:41:37 -0400
Subject: [PATCH] Recover from terminal hangs when shell integration breaks or
 the pty exits (#313312)

---
 .../executeStrategy/executeStrategy.ts        | 17 ++++++++++++
 .../browser/tools/runInTerminalTool.ts        | 27 ++++++++++++++++++-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/executeStrategy/executeStrategy.ts b/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/executeStrategy/executeStrategy.ts
index a999bd6c23e..2972141b2ac 100644
--- a/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/executeStrategy/executeStrategy.ts
+++ b/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/executeStrategy/executeStrategy.ts
@@ -243,6 +243,23 @@ export async function trackIdleOnPrompt(
 			scheduler.schedule();
 		}
 	}, 30_000));
+	// Hard wall-clock safety net for the case where shell integration never
+	// engages at all — no OSC `C`/`D` is ever parsed so state never advances
+	// to Executing, and yet the existing data-idle fallbacks somehow fail to
+	// fire (e.g. because data arrives in a single event before listeners are
+	// active, or because `onData` throttling masks idle periods). Without
+	// this, trackIdleOnPrompt can block the rich strategy for the lifetime
+	// of the chat request. Genuinely long-running commands with working
+	// shell integration reach Executing/PromptAfterExecuting before this
+	// fires, so this is purely a fallback for the broken-handshake path.
+	const hardCapScheduler = store.add(new RunOnceScheduler(() => {
+		if (state === TerminalState.Initial || state === TerminalState.Prompt) {
+			log?.(`Hard cap fired after 60s in state ${stateNames[state]} (dataEvents=${dataEventCount})`);
+			setState(TerminalState.PromptAfterExecuting, 'hardCap');
+			scheduler.schedule();
+		}
+	}, 60_000));
+	hardCapScheduler.schedule();
 	// Only schedule when a prompt sequence (A) is seen after an execute sequence (C). This prevents
 	// cases where the command is executed before the prompt is written. While not perfect, sitting
 	// on an A without a C following shortly after is a very good indicator that the command is done
diff --git a/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/runInTerminalTool.ts b/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/runInTerminalTool.ts
index cf91a703a0c..a3004c0cd1b 100644
--- a/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/runInTerminalTool.ts
+++ b/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/runInTerminalTool.ts
@@ -2282,9 +2282,34 @@ export class RunInTerminalTool extends Disposable implements IToolImpl {
 		}));
 
 		// Clean up all background resources when the terminal is disposed
-		// (e.g. user closes the terminal) to avoid leaking listeners and monitors.
+		// (e.g. user closes the terminal). Send a completion notification so
+		// the agent isn't left waiting for an `onCommandFinished` event that
+		// will never fire — the pty exited before shell integration could
+		// emit the end marker. Output captured here is whatever was buffered
+		// up until disposal.
+		// Capture the execution reference now — by the time onDisposed fires,
+		// onDidDisposeInstance listeners may have already removed it from
+		// _activeExecutions.
+		const executionForDisposal = RunInTerminalTool._activeExecutions.get(termId);
 		store.add(terminalInstance.onDisposed(() => {
+			if (handleSessionCancelled()) {
+				return;
+			}
+			const currentOutput = executionForDisposal?.getOutput() ?? '';
+			const exitCode = terminalInstance.exitCode;
+			const exitCodeText = exitCode !== undefined ? ` with exit code ${exitCode}` : '';
 			disposeNotification();
+			const message = `[Terminal ${termId} notification: terminal exited${exitCodeText}. The terminal process ended before the command could complete normally; further commands cannot be sent to this terminal ID.]\nTerminal output:\n${currentOutput}`;
+			this._logService.debug(`RunInTerminalTool: Background terminal ${termId} disposed${exitCodeText}, notifying chat session`);
+			this._chatService.sendRequest(chatSessionResource, message, {
+				...sendOptions,
+				queue: ChatRequestQueueKind.Steering,
+				isSystemInitiated: true,
+				systemInitiatedLabel: localize('terminalProcessExited', "`{0}` terminal exited", commandName),
+				terminalExecutionId: termId,
+			}).catch(e => {
+				this._logService.warn(`RunInTerminalTool: Failed to send terminal-exited notification for terminal ${termId}`, e);
+			});
 		}));
 
 		// When a checkpoint is restored, requests are removed from the model.