fix image carousel image position detection.

src/vs/workbench/contrib/chat/browser/chatImageCarouselService.ts

@@ -100,7 +100,7 @@ export async function collectCarouselSections(
 		if (dedupedImages.length > 0) {
 			sections.push({
 				title: request?.messageText ?? extractedTitle,
-				images: dedupedImages.map(({ id, name, mimeType, data, caption }) => ({ id, name, mimeType, data: data.buffer, caption }))
+				images: dedupedImages.map(({ uri, name, mimeType, data, caption }) => ({ id: uri.toString(), name, mimeType, data: data.buffer, caption }))
 			});
 		}
 	}
@@ -118,7 +118,7 @@ export async function collectCarouselSections(
 		if (dedupedImages.length > 0) {
 			sections.push({
 				title: item.messageText,
-				images: dedupedImages.map(({ id, name, mimeType, data, caption }) => ({ id, name, mimeType, data: data.buffer, caption }))
+				images: dedupedImages.map(({ uri, name, mimeType, data, caption }) => ({ id: uri.toString(), name, mimeType, data: data.buffer, caption }))
 			});
 		}
 	}
@@ -151,7 +151,20 @@ export function findClickedImageIndex(
 	let globalOffset = 0;
 
 	for (const section of sections) {
-		const localIndex = findImageInList(section.images, resource, data);
+		const localIndex = findImageInListByUri(section.images, resource);
+		if (localIndex >= 0) {
+			return globalOffset + localIndex;
+		}
+		globalOffset += section.images.length;
+	}
+
+	if (!data) {
+		return -1;
+	}
+
+	globalOffset = 0;
+	for (const section of sections) {
+		const localIndex = findImageInListByData(section.images, data);
 		if (localIndex >= 0) {
 			return globalOffset + localIndex;
 		}
@@ -161,10 +174,9 @@ export function findClickedImageIndex(
 	return -1;
 }
 
-function findImageInList(
+function findImageInListByUri(
 	images: ICarouselImage[],
 	resource: URI,
-	data?: Uint8Array,
 ): number {
 	// Try matching by URI string (for inline references and tool images with URIs)
 	const uriStr = resource.toString();
@@ -185,15 +197,14 @@ function findImageInList(
 		return byParsedUri;
 	}
 
-	// Fall back to matching by data buffer equality
-	if (data) {
-		const wrapped = VSBuffer.wrap(data);
-		return images.findIndex(img => VSBuffer.wrap(img.data).equals(wrapped));
-	}
-
 	return -1;
 }
 
+function findImageInListByData(images: ICarouselImage[], data: Uint8Array): number {
+	const wrapped = VSBuffer.wrap(data);
+	return images.findIndex(img => VSBuffer.wrap(img.data).equals(wrapped));
+}
+
 /**
  * Builds the collection arguments for the carousel command.
  */

src/vs/workbench/contrib/chat/test/browser/chatImageCarouselService.test.ts

@@ -8,8 +8,11 @@ import { VSBuffer } from '../../../../../base/common/buffer.js';
 import { ensureNoDisposablesAreLeakedInTestSuite } from '../../../../../base/test/common/utils.js';
 import { URI } from '../../../../../base/common/uri.js';
 import { buildCollectionArgs, buildSingleImageArgs, collectCarouselSections, findClickedImageIndex, ICarouselSection } from '../../browser/chatImageCarouselService.js';
+import { IChatToolInvocationSerialized } from '../../common/chatService/chatService.js';
+import { ChatResponseResource } from '../../common/model/chatModel.js';
 import { IImageVariableEntry } from '../../common/attachments/chatVariableEntries.js';
 import { IChatRequestViewModel, IChatResponseViewModel } from '../../common/model/chatViewModel.js';
+import { ToolDataSource } from '../../common/tools/languageModelToolsService.js';
 
 suite('ChatImageCarouselService helpers', () => {
 	ensureNoDisposablesAreLeakedInTestSuite();
@@ -35,12 +38,12 @@ suite('ChatImageCarouselService helpers', () => {
 		} as unknown as IChatRequestViewModel;
 	}
 
-	function makeResponse(requestId: string, id: string = 'resp-1'): IChatResponseViewModel {
+	function makeResponse(requestId: string, id: string = 'resp-1', responseValue: IChatResponseViewModel['response']['value'] = []): IChatResponseViewModel {
 		return {
 			id,
 			requestId,
 			sessionResource: URI.parse('chat-session://test/session'),
-			response: { value: [] },
+			response: { value: responseValue },
 			session: { getItems: () => [] },
 			setVote: () => { },
 		} as unknown as IChatResponseViewModel;
@@ -104,6 +107,28 @@ suite('ChatImageCarouselService helpers', () => {
 			assert.strictEqual(findClickedImageIndex(sections, unknownUri, new Uint8Array([30, 40])), 1);
 		});
 
+		test('prefers a later exact URI match over an earlier image with identical data', () => {
+			const firstUri = URI.parse('vscode-chat-response-resource://session/tool-call-1/0/file.png');
+			const secondUri = URI.parse('vscode-chat-response-resource://session/tool-call-2/0/file.png');
+			const identicalData = new Uint8Array([10, 20, 30]);
+			const sections: ICarouselSection[] = [
+				{
+					title: 'Earlier',
+					images: [
+						{ id: firstUri.toString(), name: 'first.png', mimeType: 'image/png', data: identicalData },
+					],
+				},
+				{
+					title: 'Later',
+					images: [
+						{ id: secondUri.toString(), name: 'second.png', mimeType: 'image/png', data: identicalData },
+					],
+				},
+			];
+
+			assert.strictEqual(findClickedImageIndex(sections, secondUri, identicalData), 1);
+		});
+
 		test('returns -1 for empty sections', () => {
 			assert.strictEqual(findClickedImageIndex([], URI.file('/x.png')), -1);
 		});
@@ -283,6 +308,42 @@ suite('ChatImageCarouselService helpers', () => {
 			assert.strictEqual(result[0].images.length, 3);
 		});
 
+		test('uses tool image URIs as carousel image ids', async () => {
+			const request = makeRequest('req-1', [], 'Request with tool output image');
+			const toolCallId = 'tool-call-1';
+			const sessionResource = URI.parse('chat-session://test/session');
+			const expectedUri = ChatResponseResource.createUri(sessionResource, toolCallId, 0, 'file.png').toString();
+			const response = makeResponse('req-1', 'resp-1', [
+				{
+					kind: 'toolInvocationSerialized',
+					toolId: 'test_tool',
+					toolCallId,
+					invocationMessage: 'Took screenshot',
+					originMessage: undefined,
+					pastTenseMessage: undefined,
+					presentation: undefined,
+					resultDetails: {
+						output: {
+							type: 'data',
+							mimeType: 'image/png',
+							base64Data: 'AQID'
+						}
+					},
+					isConfirmed: { type: 0 },
+					isComplete: true,
+					source: ToolDataSource.Internal,
+					generatedTitle: undefined,
+					isAttachedToThinking: false,
+				} as unknown as IChatToolInvocationSerialized,
+			]);
+
+			const result = await collectCarouselSections([request, response], async () => new Uint8Array());
+
+			assert.strictEqual(result.length, 1);
+			assert.strictEqual(result[0].images.length, 1);
+			assert.strictEqual(result[0].images[0].id, expectedUri);
+		});
+
 		test('image data is a plain Uint8Array usable by Blob constructor', async () => {
 			const request = makeRequest('req-1', [
 				makeImageVariableEntry({ value: new Uint8Array([1, 2, 3]) }),