From 0e521942a3d7e317ded68b91f6c00efcc8810724 Mon Sep 17 00:00:00 2001
From: chunhtai <47866232+chunhtai@users.noreply.github.com>
Date: Thu, 14 Sep 2023 14:00:55 -0700
Subject: [PATCH] Allows page removal that contains Localhistoryentry (#134757)

fixes https://github.com/flutter/flutter/issues/97836
fixes https://github.com/flutter/flutter/issues/134752
fixes https://github.com/flutter/flutter/issues/118645
---
 .../flutter/lib/src/widgets/navigator.dart    | 18 ++++
 packages/flutter/lib/src/widgets/routes.dart  |  8 --
 .../flutter/test/widgets/navigator_test.dart  | 84 +++++++++++++++++++
 3 files changed, 102 insertions(+), 8 deletions(-)

diff --git a/packages/flutter/lib/src/widgets/navigator.dart b/packages/flutter/lib/src/widgets/navigator.dart
index e2f350d299b0..41b570be858f 100644
--- a/packages/flutter/lib/src/widgets/navigator.dart
+++ b/packages/flutter/lib/src/widgets/navigator.dart
@@ -2927,6 +2927,10 @@ class _RouteEntry extends RouteTransitionRecord {
   final _RestorationInformation? restorationInformation;
   final bool pageBased;
 
+  /// The limit this route entry will attempt to pop in the case of route being
+  /// remove as a result of a page update.
+  static const int kDebugPopAttemptLimit = 100;
+
   static final Route<dynamic> notAnnounced = _NotAnnounced();
 
   _RouteLifecycle currentState;
@@ -3268,6 +3272,20 @@ class _RouteEntry extends RouteTransitionRecord {
       'This route cannot be marked for pop. Either a decision has already been '
       'made or it does not require an explicit decision on how to transition out.',
     );
+    // Remove state that prevents a pop, e.g. LocalHistoryEntry[s].
+    int attempt = 0;
+    while (route.willHandlePopInternally) {
+      assert(
+        () {
+          attempt += 1;
+          return attempt < kDebugPopAttemptLimit;
+        }(),
+        'Attempted to pop $route $kDebugPopAttemptLimit times, but still failed',
+      );
+      final bool popResult = route.didPop(result);
+      assert(!popResult);
+
+    }
     pop<dynamic>(result);
     _isWaitingForExitingDecision = false;
   }
diff --git a/packages/flutter/lib/src/widgets/routes.dart b/packages/flutter/lib/src/widgets/routes.dart
index b51cb4f61c7c..d779df692d58 100644
--- a/packages/flutter/lib/src/widgets/routes.dart
+++ b/packages/flutter/lib/src/widgets/routes.dart
@@ -1832,14 +1832,6 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
     ];
   }
 
-  @override
-  bool get willHandlePopInternally {
-    final bool popEntriesCanPop = _popEntries.every((PopEntry popEntry) {
-      return popEntry.canPopNotifier.value;
-    });
-    return !popEntriesCanPop || super.willHandlePopInternally;
-  }
-
   @override
   String toString() => '${objectRuntimeType(this, 'ModalRoute')}($settings, animation: $_animation)';
 }
diff --git a/packages/flutter/test/widgets/navigator_test.dart b/packages/flutter/test/widgets/navigator_test.dart
index 886de4a71269..8044583a7b27 100644
--- a/packages/flutter/test/widgets/navigator_test.dart
+++ b/packages/flutter/test/widgets/navigator_test.dart
@@ -2910,6 +2910,90 @@ void main() {
       );
     });
 
+    testWidgets('Can pop route with local history entries using page api', (WidgetTester tester) async {
+      List<Page<void>> myPages = const <Page<void>>[
+        MaterialPage<void>(child: Text('page1')),
+        MaterialPage<void>(child: Text('page2')),
+      ];
+      await tester.pumpWidget(
+        MediaQuery(
+          data: MediaQueryData.fromView(tester.view),
+          child: Localizations(
+            locale: const Locale('en', 'US'),
+            delegates: const <LocalizationsDelegate<dynamic>>[
+              DefaultMaterialLocalizations.delegate,
+              DefaultWidgetsLocalizations.delegate,
+            ],
+            child: Navigator(
+              pages: myPages,
+              onPopPage: (_, __) => false,
+            ),
+          ),
+        ),
+      );
+      expect(find.text('page2'), findsOneWidget);
+      final ModalRoute<void> route = ModalRoute.of(tester.element(find.text('page2')))!;
+      bool entryRemoved = false;
+      route.addLocalHistoryEntry(LocalHistoryEntry(onRemove: () => entryRemoved = true));
+      expect(route.willHandlePopInternally, true);
+
+      myPages = const <Page<void>>[
+        MaterialPage<void>(child: Text('page1')),
+      ];
+
+      await tester.pumpWidget(
+        MediaQuery(
+          data: MediaQueryData.fromView(tester.view),
+          child: Localizations(
+            locale: const Locale('en', 'US'),
+            delegates: const <LocalizationsDelegate<dynamic>>[
+              DefaultMaterialLocalizations.delegate,
+              DefaultWidgetsLocalizations.delegate,
+            ],
+            child: Navigator(
+              pages: myPages,
+              onPopPage: (_, __) => false,
+            ),
+          ),
+        ),
+      );
+      expect(find.text('page1'), findsOneWidget);
+      expect(entryRemoved, isTrue);
+    });
+
+    testWidgets('ModalRoute must comply with willHandlePopInternally when there is a PopScope', (WidgetTester tester) async {
+      const List<Page<void>> myPages = <Page<void>>[
+        MaterialPage<void>(child: Text('page1')),
+        MaterialPage<void>(
+          child: PopScope(
+            canPop: false,
+            child: Text('page2'),
+          ),
+        ),
+      ];
+      await tester.pumpWidget(
+        MediaQuery(
+          data: MediaQueryData.fromView(tester.view),
+          child: Localizations(
+            locale: const Locale('en', 'US'),
+            delegates: const <LocalizationsDelegate<dynamic>>[
+              DefaultMaterialLocalizations.delegate,
+              DefaultWidgetsLocalizations.delegate,
+            ],
+            child: Navigator(
+              pages: myPages,
+              onPopPage: (_, __) => false,
+            ),
+          ),
+        ),
+      );
+      final ModalRoute<void> route = ModalRoute.of(tester.element(find.text('page2')))!;
+      // PopScope only prevents user trigger action, e.g. Navigator.maybePop.
+      // The page can still be popped by the system if it needs to.
+      expect(route.willHandlePopInternally, false);
+      expect(route.didPop(null), true);
+    });
+
     testWidgets('can push and pop pages using page api', (WidgetTester tester) async {
       late Animation<double> secondaryAnimationOfRouteOne;
       late Animation<double> primaryAnimationOfRouteOne;