From 6601c31c6b5abe060be207907bd3bdcc6f13c418 Mon Sep 17 00:00:00 2001
From: "vs-code-engineering[bot]"
 <122617954+vs-code-engineering[bot]@users.noreply.github.com>
Date: Fri, 8 May 2026 15:16:02 +0000
Subject: [PATCH 1/2] fix: guard setDimensions against disposed ptyProcessReady
 (fixes #315282)

When a terminal process manager is disposed, ptyProcessReady is set to
undefined. If setDimensions is called after disposal (e.g., during a
resize triggered by a configuration change event that fires during the
dispose sequence), calling .then() on undefined throws a TypeError.

Add a guard clause to return early when ptyProcessReady is undefined,
preventing the crash without masking the error from telemetry.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../contrib/terminal/browser/terminalProcessManager.ts         | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts b/src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts
index 274c4b481e5b9..0c7cec8eca3c4 100644
--- a/src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts
+++ b/src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts
@@ -605,6 +605,9 @@ export class TerminalProcessManager extends Disposable implements ITerminalProce
 			return;
 		}
 
+		if (!this.ptyProcessReady) {
+			return Promise.resolve();
+		}
 		return this.ptyProcessReady.then(() => this._resize(cols, rows, pixelWidth, pixelHeight));
 	}
 

From 7871d48508646356a4939c9b02d48220525c59cd Mon Sep 17 00:00:00 2001
From: "vs-code-engineering[bot]"
 <122617954+vs-code-engineering[bot]@users.noreply.github.com>
Date: Fri, 8 May 2026 20:33:02 +0000
Subject: [PATCH 2/2] fix: dispose resize debouncer before process manager to
 prevent race

Dispose _resizeDebouncer before _processManager.dispose() so that no
resize callbacks can fire after ptyProcessReady has been nulled. This
addresses the root cause (disposal ordering) rather than just guarding
against the symptom, as suggested by @bryanchen-d.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../workbench/contrib/terminal/browser/terminalInstance.ts   | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts b/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
index 588c01f8628d2..b7c26c253a76d 100644
--- a/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
+++ b/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
@@ -1330,6 +1330,11 @@ export class TerminalInstance extends Disposable implements ITerminalInstance {
 			this._exitReason = reason ?? TerminalExitReason.Unknown;
 		}
 
+		// Dispose the resize debouncer before the process manager so that no
+		// resize callbacks can fire after ptyProcessReady has been nulled.
+		this._resizeDebouncer?.dispose();
+		this._resizeDebouncer = undefined;
+
 		this._processManager.dispose();
 		// Process manager dispose/shutdown doesn't fire process exit, trigger with undefined if it
 		// hasn't happened yet