From 4bed76757db7a4eea74d77d5a63804ef52198f37 Mon Sep 17 00:00:00 2001
From: xubaolin <xubaolin@oppo.com>
Date: Sun, 8 May 2022 02:44:08 +0800
Subject: [PATCH] Fix a `_WrappedScrollBehavior.shouldNotify` bug (#103267)

---
 .../flutter/lib/src/widgets/scroll_configuration.dart     | 2 +-
 packages/flutter/test/widgets/scroll_behavior_test.dart   | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/packages/flutter/lib/src/widgets/scroll_configuration.dart b/packages/flutter/lib/src/widgets/scroll_configuration.dart
index fdb1b613592c..46fc042f9d0d 100644
--- a/packages/flutter/lib/src/widgets/scroll_configuration.dart
+++ b/packages/flutter/lib/src/widgets/scroll_configuration.dart
@@ -348,7 +348,7 @@ class _WrappedScrollBehavior implements ScrollBehavior {
         || oldDelegate.overscroll != overscroll
         || oldDelegate.physics != physics
         || oldDelegate.platform != platform
-        || setEquals<PointerDeviceKind>(oldDelegate.dragDevices, dragDevices)
+        || !setEquals<PointerDeviceKind>(oldDelegate.dragDevices, dragDevices)
         || delegate.shouldNotify(oldDelegate.delegate);
   }
 
diff --git a/packages/flutter/test/widgets/scroll_behavior_test.dart b/packages/flutter/test/widgets/scroll_behavior_test.dart
index b45583b6fccf..a6cbd6428e0c 100644
--- a/packages/flutter/test/widgets/scroll_behavior_test.dart
+++ b/packages/flutter/test/widgets/scroll_behavior_test.dart
@@ -32,6 +32,14 @@ class TestScrollBehavior extends ScrollBehavior {
 }
 
 void main() {
+  // Regression test for https://github.com/flutter/flutter/issues/89681
+  testWidgets('_WrappedScrollBehavior shouldNotify test', (WidgetTester tester) async {
+    final ScrollBehavior behavior1 = const ScrollBehavior().copyWith();
+    final ScrollBehavior behavior2 = const ScrollBehavior().copyWith();
+
+    expect(behavior1.shouldNotify(behavior2), false);
+  });
+
   testWidgets('Inherited ScrollConfiguration changed', (WidgetTester tester) async {
     final GlobalKey key = GlobalKey(debugLabel: 'scrollable');
     TestScrollBehavior? behavior;