fix #25143 Successive calls to `precacheImage()` throw an exception (#25159)
diff --git a/AUTHORS b/AUTHORS index 67cc5d4..ec25d3e 100644 --- a/AUTHORS +++ b/AUTHORS
@@ -32,3 +32,4 @@ Stefan Mitev <mr.mitew@gmail.com> Jasper van Riet <jaspervanriet@gmail.com> Mattijs Fuijkschot <mattijs.fuijkschot@gmail.com> +TruongSinh Tran-Nguyen <i@truongsinh.pro>
diff --git a/packages/flutter/lib/src/widgets/image.dart b/packages/flutter/lib/src/widgets/image.dart index 9711823..b7d068a 100644 --- a/packages/flutter/lib/src/widgets/image.dart +++ b/packages/flutter/lib/src/widgets/image.dart
@@ -83,9 +83,11 @@ final ImageStream stream = provider.resolve(config); void listener(ImageInfo image, bool sync) { completer.complete(); + stream.removeListener(listener); } void errorListener(dynamic exception, StackTrace stackTrace) { completer.complete(); + stream.removeListener(listener); if (onError != null) { onError(exception, stackTrace); } else { @@ -99,7 +101,6 @@ } } stream.addListener(listener, onError: errorListener); - completer.future.then<void>((void value) { stream.removeListener(listener); }); return completer.future; }
diff --git a/packages/flutter/test/widgets/image_test.dart b/packages/flutter/test/widgets/image_test.dart index 7c17a95..f0b9ea4 100644 --- a/packages/flutter/test/widgets/image_test.dart +++ b/packages/flutter/test/widgets/image_test.dart
@@ -621,6 +621,28 @@ expect(isSync, isTrue); }); + testWidgets('Precache remove listeners immediately after future completes, does not crash on successive calls #25143', (WidgetTester tester) async { + final TestImageStreamCompleter imageStreamCompleter = TestImageStreamCompleter(); + final TestImageProvider provider = TestImageProvider(streamCompleter: imageStreamCompleter); + + await tester.pumpWidget( + Builder( + builder: (BuildContext context) { + precacheImage(provider, context); + return Container(); + } + ) + ); + + expect(imageStreamCompleter.listeners.length, 2); + imageStreamCompleter.listeners.keys.toList()[1](null, null); + + expect(imageStreamCompleter.listeners.length, 1); + imageStreamCompleter.listeners.keys.toList()[0](null, null); + + expect(imageStreamCompleter.listeners.length, 0); + }); + testWidgets('Precache completes with onError on error', (WidgetTester tester) async { dynamic capturedException; StackTrace capturedStackTrace;