Fix question carousel reappearing after window reload (#295007)

src/vs/workbench/contrib/chat/common/model/chatModel.ts

@@ -2311,6 +2311,17 @@ export class ChatModel extends Disposable implements IChatModel {
 				modelState = { value: ResponseModelState.Cancelled, completedAt: Date.now() };
 			}
 
+			// Mark question carousels as used after
+			// deserialization. After a reload, the extension is no longer listening for
+			// their responses, so they cannot be interacted with.
+			if (raw.response) {
+				for (const part of raw.response) {
+					if (hasKey(part, { kind: true }) && (part.kind === 'questionCarousel')) {
+						part.isUsed = true;
+					}
+				}
+			}
+
 			request.response = new ChatResponseModel({
 				responseContent: raw.response ?? [new MarkdownString(raw.response)],
 				session: this,

src/vs/workbench/contrib/chat/test/common/model/chatModel.test.ts

@@ -167,6 +167,51 @@ suite('ChatModel', () => {
 		assert.strictEqual(request1.response!.shouldBeRemovedOnSend, undefined);
 	});
 
+	test('deserialization marks unused question carousels as used', async () => {
+		const serializableData: ISerializableChatData3 = {
+			version: 3,
+			sessionId: 'test-session',
+			creationDate: Date.now(),
+			customTitle: undefined,
+			initialLocation: ChatAgentLocation.Chat,
+			requests: [{
+				requestId: 'req1',
+				message: { text: 'hello', parts: [] },
+				variableData: { variables: [] },
+				response: [
+					{ value: 'some text', isTrusted: false },
+					{
+						kind: 'questionCarousel' as const,
+						questions: [{ id: 'q1', title: 'Question 1', type: 'text' as const }],
+						allowSkip: true,
+						resolveId: 'resolve1',
+						isUsed: false,
+					},
+				],
+				modelState: { value: 2 /* ResponseModelState.Cancelled */, completedAt: Date.now() },
+			}],
+			responderUsername: 'bot',
+		};
+
+		const model = testDisposables.add(instantiationService.createInstance(
+			ChatModel,
+			{ value: serializableData, serializer: undefined! },
+			{ initialLocation: ChatAgentLocation.Chat, canUseTools: true }
+		));
+
+		const requests = model.getRequests();
+		assert.strictEqual(requests.length, 1);
+		const response = requests[0].response!;
+
+		// The question carousel should be marked as used after deserialization
+		const carouselPart = response.response.value.find(p => p.kind === 'questionCarousel');
+		assert.ok(carouselPart);
+		assert.strictEqual(carouselPart.isUsed, true);
+
+		// The response should be complete (not stuck in NeedsInput)
+		assert.strictEqual(response.isComplete, true);
+	});
+
 	test('inputModel.toJSON filters extension-contributed contexts', async function () {
 		const model = testDisposables.add(instantiationService.createInstance(ChatModel, undefined, { initialLocation: ChatAgentLocation.Chat, canUseTools: true }));