fix #116049 (#116319)

Author: bpasero

src/vs/base/common/stream.ts

@@ -495,9 +495,13 @@ export function consumeStream<T>(stream: ReadableStreamEvents<T>, reducer: IRedu
 	return new Promise((resolve, reject) => {
 		const chunks: T[] = [];
 
-		stream.on('data', data => chunks.push(data));
 		stream.on('error', error => reject(error));
 		stream.on('end', () => resolve(reducer(chunks)));
+
+		// Adding the `data` listener will turn the stream
+		// into flowing mode. As such it is important to
+		// add this listener last (DO NOT CHANGE!)
+		stream.on('data', data => chunks.push(data));
 	});
 }
 

src/vs/platform/files/test/electron-browser/diskFileService.test.ts

@@ -1584,6 +1584,20 @@ flakySuite('Disk File Service', function () {
 		assert.strictEqual(error!.fileOperationResult, FileOperationResult.FILE_TOO_LARGE);
 	}
 
+	(isWindows ? test.skip /* windows: cannot create file symbolic link without elevated context */ : test)('readFile - dangling symbolic link - https://github.com/microsoft/vscode/issues/116049', async () => {
+		const link = URI.file(join(testDir, 'small.js-link'));
+		await symlink(join(testDir, 'small.js'), link.fsPath);
+
+		let error: FileOperationError | undefined = undefined;
+		try {
+			await service.readFile(link);
+		} catch (err) {
+			error = err;
+		}
+
+		assert.ok(error);
+	});
+
 	test('createFile', async () => {
 		return assertCreateFile(contents => VSBuffer.fromString(contents));
 	});