fix #59733

src/vs/platform/actions/common/actions.ts

@@ -11,7 +11,7 @@ import { IConstructorSignature2, createDecorator } from 'vs/platform/instantiati
 import { IKeybindings } from 'vs/platform/keybinding/common/keybindingsRegistry';
 import { ContextKeyExpr, IContextKeyService } from 'vs/platform/contextkey/common/contextkey';
 import { ICommandService } from 'vs/platform/commands/common/commands';
-import { IDisposable } from 'vs/base/common/lifecycle';
+import { IDisposable, dispose } from 'vs/base/common/lifecycle';
 import { Event } from 'vs/base/common/event';
 import { URI, UriComponents } from 'vs/base/common/uri';
 
@@ -233,11 +233,12 @@ export class SubmenuItemAction extends Action {
 
 export class MenuItemAction extends ExecuteCommandAction {
 
-	private _options: IMenuActionOptions;
-
 	readonly item: ICommandAction;
 	readonly alt: MenuItemAction;
 
+	private _options: IMenuActionOptions;
+	private _contextListener: IDisposable;
+
 	constructor(
 		item: ICommandAction,
 		alt: ICommandAction,
@@ -252,6 +253,19 @@ export class MenuItemAction extends ExecuteCommandAction {
 
 		this.item = item;
 		this.alt = alt ? new MenuItemAction(alt, undefined, this._options, contextKeyService, commandService) : undefined;
+
+		if (item.precondition) {
+			const preconditionKeysSet = new Set<string>();
+			for (let key of item.precondition.keys()) {
+				preconditionKeysSet.add(key);
+			}
+
+			this._contextListener = contextKeyService.onDidChangeContext(event => {
+				if (event.affectsSome(preconditionKeysSet)) {
+					this._setEnabled(contextKeyService.contextMatchesRules(item.precondition));
+				}
+			});
+		}
 	}
 
 	run(...args: any[]): TPromise<any> {
@@ -267,6 +281,12 @@ export class MenuItemAction extends ExecuteCommandAction {
 
 		return super.run(...runArgs);
 	}
+
+	dispose(): void {
+		this._contextListener = dispose(this._contextListener);
+
+		super.dispose();
+	}
 }
 
 export class SyncActionDescriptor {