From c546f7cc8ac440a08240246ac2f55771c220a497 Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Fri, 31 Mar 2023 12:11:50 -0700
Subject: [PATCH] Ensure Decoration.isDisposed can be true

Fixes #4410
---
 src/common/services/DecorationService.test.ts | 30 +++++++++++++++++++
 src/common/services/DecorationService.ts      |  2 +-
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 src/common/services/DecorationService.test.ts

diff --git a/src/common/services/DecorationService.test.ts b/src/common/services/DecorationService.test.ts
new file mode 100644
index 0000000000..a2cb56d266
--- /dev/null
+++ b/src/common/services/DecorationService.test.ts
@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) 2019 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { assert } from 'chai';
+import { DecorationService } from './DecorationService';
+import { EventEmitter } from 'common/EventEmitter';
+import { IMarker } from 'common/Types';
+import { Disposable } from 'common/Lifecycle';
+
+const fakeMarker: IMarker = Object.freeze(new class extends Disposable {
+  public readonly id = 1;
+  public readonly line = 1;
+  public readonly isDisposed = false;
+  public readonly onDispose = new EventEmitter<void>().event;
+}());
+
+describe('DecorationService', () => {
+  it('should set isDisposed to true after dispose', () => {
+    const service = new DecorationService();
+    const decoration = service.registerDecoration({
+      marker: fakeMarker
+    });
+    assert.ok(decoration);
+    assert.isFalse(decoration!.isDisposed);
+    decoration!.dispose();
+    assert.isTrue(decoration!.isDisposed);
+  });
+});
diff --git a/src/common/services/DecorationService.ts b/src/common/services/DecorationService.ts
index 881b3d0784..1ccc712c41 100644
--- a/src/common/services/DecorationService.ts
+++ b/src/common/services/DecorationService.ts
@@ -104,7 +104,7 @@ export class DecorationService extends Disposable implements IDecorationService
 class Decoration extends Disposable implements IInternalDecoration {
   public readonly marker: IMarker;
   public element: HTMLElement | undefined;
-  public isDisposed: boolean = false;
+  public get isDisposed(): boolean { return this._isDisposed; }
 
   public readonly onRenderEmitter = this.register(new EventEmitter<HTMLElement>());
   public readonly onRender = this.onRenderEmitter.event;