[tests] Enable back some MemoryLeak tests

src/Controls/src/Core/Compatibility/Handlers/Android/FrameRenderer.cs

@@ -420,6 +420,14 @@ void IElementHandler.Invoke(string command, object? args)
 
 		void IElementHandler.DisconnectHandler()
 		{
+			// Disconnect the content's handler to break circular references and allow GC.
+			// This is important for memory leak prevention - when a Frame is being removed,
+			// its content (ListView, etc.) should also be disconnected.
+			if (Element?.Content is IView content)
+			{
+				content.Handler?.DisconnectHandler();
+			}
+
 			_viewHandlerWrapper.DisconnectHandler();
 		}
 

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellFlyoutRecyclerAdapter.cs

@@ -35,9 +35,9 @@ public ShellFlyoutRecyclerAdapter(IShellContext shellContext, Action<Element> se
 			_selectedCallback = selectedCallback;
 		}
 
-		public override int ItemCount => _listItems.Count;
+		public override int ItemCount => _listItems?.Count ?? 0;
 
-		protected Shell Shell => _shellContext.Shell;
+		protected Shell Shell => _shellContext?.Shell;
 
 		IShellController ShellController => (IShellController)Shell;
 
@@ -47,11 +47,16 @@ public ShellFlyoutRecyclerAdapter(IShellContext shellContext, Action<Element> se
 
 		public override int GetItemViewType(int position)
 		{
+			if (_listItems == null || position >= _listItems.Count)
+				return -1;
 			return _listItems[position].Index;
 		}
 
 		DataTemplate GetDataTemplate(int viewTypeId)
 		{
+			if (_listItems == null)
+				return null;
+
 			AdapterListItem item = null;
 
 			foreach (var ali in _listItems)
@@ -81,6 +86,9 @@ DataTemplate GetDataTemplate(int viewTypeId)
 
 		public override void OnViewRecycled(Java.Lang.Object holder)
 		{
+			if (_listItems == null)
+				return;
+
 			if (holder is ElementViewHolder evh)
 			{
 				// only clear out the Element if the item has been removed
@@ -103,6 +111,9 @@ public override void OnViewRecycled(Java.Lang.Object holder)
 
 		public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
 		{
+			if (_listItems == null || position >= _listItems.Count)
+				return;
+
 			var item = _listItems[position];
 			var elementHolder = (ElementViewHolder)holder;
 

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellRenderer.cs

@@ -218,6 +218,9 @@ protected virtual void OnElementSet(Shell shell)
 
 		protected virtual void SwitchFragment(FragmentManager manager, AView targetView, ShellItem newItem, bool animate = true)
 		{
+			if (_disposed || targetView == null)
+				return;
+
 			var previousView = _currentView;
 			_currentView = CreateShellItemRenderer(newItem);
 			_currentView.ShellItem = newItem;
@@ -316,9 +319,39 @@ void IElementHandler.DisconnectHandler()
 
 			_disposed = true;
 
-			Element.PropertyChanged -= OnElementPropertyChanged;
-			Element.SizeChanged -= OnElementSizeChanged;
-			((IShellController)Element).RemoveAppearanceObserver(this);
+			if (Element != null)
+			{
+				Element.PropertyChanged -= OnElementPropertyChanged;
+				Element.SizeChanged -= OnElementSizeChanged;
+				((IShellController)Element).RemoveAppearanceObserver(this);
+			}
+
+			// Execute any pending fragment transactions and remove the current fragment
+			// BEFORE the container is removed to prevent "No view found for id" crashes
+			try
+			{
+				var fragmentManager = Element?.FindMauiContext()?.GetFragmentManager();
+				if (fragmentManager != null && !fragmentManager.IsDestroyed)
+				{
+					fragmentManager.ExecutePendingTransactions();
+
+					if (_currentView?.Fragment != null && _currentView.Fragment.IsAdded)
+					{
+						var transaction = fragmentManager.BeginTransactionEx();
+						transaction.RemoveEx(_currentView.Fragment);
+						transaction.CommitAllowingStateLossEx();
+						fragmentManager.ExecutePendingTransactions();
+					}
+				}
+			}
+			catch (Java.Lang.IllegalArgumentException)
+			{
+				// Fragment container may already be removed - ignore
+			}
+			catch (Java.Lang.IllegalStateException)
+			{
+				// Fragment manager may be in an invalid state - ignore
+			}
 
 			if (_flyoutView is ShellFlyoutRenderer sfr)
 				sfr.Disconnect();
@@ -328,7 +361,7 @@ void IElementHandler.DisconnectHandler()
 			if (_currentView is ShellItemRendererBase sir)
 				sir.Disconnect();
 			else
-				_currentView.Dispose();
+				_currentView?.Dispose();
 
 			_currentView = null;
 

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellToolbarTracker.cs

@@ -187,7 +187,17 @@ protected override void Dispose(bool disposing)
 				if (_backButtonBehavior != null)
 					_backButtonBehavior.PropertyChanged -= OnBackButtonBehaviorChanged;
 
-				((IShellController)ShellContext.Shell)?.RemoveFlyoutBehaviorObserver(this);
+				// Wrap in try-catch because the JNI peer may already be disposed by the time
+				// this is called, and RemoveFlyoutBehaviorObserver uses List.Remove which
+				// calls Equals() - which fails for disposed Java objects.
+				try
+				{
+					((IShellController)ShellContext.Shell)?.RemoveFlyoutBehaviorObserver(this);
+				}
+				catch (ObjectDisposedException)
+				{
+					// Ignore - we're disposing anyway
+				}
 				_shellRootToolBar.PropertyChanged -= OnToolbarPropertyChanged;
 				_shell.Navigated -= OnShellNavigated;
 				_shell.PropertyChanged -= HandleShellPropertyChanged;

src/Controls/src/Core/FlyoutPage/FlyoutPage.cs

@@ -350,10 +350,33 @@ void OnWindowChanged(object sender, EventArgs e)
 				SizeChanged -= OnSizeChanged;
 				SizeChanged += OnSizeChanged;
 				DeviceDisplay.MainDisplayInfoChanged -= OnMainDisplayInfoChanged;
+
+				// Propagate Window = null to children so they can clean up their resources.
+				// This is necessary because Window propagation only happens when Parent changes,
+				// not when parent's Window changes. Without this, children like NavigationPage
+				// won't know they've been removed from the window and won't clean up their toolbar.
+				if (Detail is IWindowController detailWindowController)
+				{
+					detailWindowController.Window = null;
+				}
+				if (Flyout is IWindowController flyoutWindowController)
+				{
+					flyoutWindowController.Window = null;
+				}
 			}
 			else
 			{
 				DeviceDisplay.MainDisplayInfoChanged += OnMainDisplayInfoChanged;
+
+				// Propagate Window to children
+				if (Detail is IWindowController detailWindowController)
+				{
+					detailWindowController.Window = Window;
+				}
+				if (Flyout is IWindowController flyoutWindowController)
+				{
+					flyoutWindowController.Window = Window;
+				}
 			}
 		}
 

src/Controls/src/Core/NavigationPage/NavigationPageToolbar.cs

@@ -331,7 +331,13 @@ internal void Disconnect()
 					navPage.ChildAdded -= NavigationPageChildrenChanged;
 					navPage.ChildRemoved -= NavigationPageChildrenChanged;
 				}
+				// Clear the list to release references to NavigationPages
+				_navigationPagesStack.Clear();
 			}
+
+			// Clear page references to allow GC
+			_currentNavigationPage = null;
+			_currentPage = null;
 		}
 	}
 }

src/Controls/src/Xaml/MarkupExtensions/StaticExtension.cs

@@ -1,8 +1,8 @@
-using System;
+susing System;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reflection;
 using System.Xml;
 
 namespace Microsoft.Maui.Controls.Xaml
 {
@@ -29,9 +29,9 @@
 			if (string.IsNullOrEmpty(Member) || Member.IndexOf(".", StringComparison.Ordinal) == -1)
 				throw new XamlParseException("Syntax for x:Static is [Member=][prefix:]typeName.staticMemberName", serviceProvider);
 
-#pragma warning disable CA1865 // Use 'string.LastIndexOf(char)' - CA1307 requires StringComparison
-			var dotIdx = Member.LastIndexOf(".", StringComparison.Ordinal);
-#pragma warning restore CA1865
+#pragma warning disable CA1307 // Specify StringComparison for clarity - char overload doesn't have StringComparison
+			var dotIdx = Member.LastIndexOf('.');
+#pragma warning restore CA1307
 			var typename = Member.Substring(0, dotIdx);
 			var membername = Member.Substring(dotIdx + 1);
 

src/Controls/tests/Core.UnitTests/CollectionViewTests.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Threading.Tasks;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Handlers.Items;
+using Xunit;
+
+namespace Microsoft.Maui.Controls.Core.UnitTests
+{
+	public class CollectionViewTests : BaseTestFixture
+	{
+		[Fact, Category(TestCategory.Memory)]
+		public async Task CanCollectEmptyView()
+		{
+			var collectionView = new CollectionView { IsPlatformEnabled = true };
+			collectionView.EmptyView = new View();
+
+			var weakReference = new WeakReference(collectionView.EmptyView);
+
+			collectionView.EmptyView = null;
+
+			await Task.Yield();
+			GC.Collect(2);
+			GC.WaitForPendingFinalizers();
+
+			Assert.False(weakReference.IsAlive);
+		}
+	}
+}

src/Controls/tests/Core.UnitTests/TestHelpers.cs

@@ -37,4 +37,4 @@ public static async Task<bool> WaitForCollect(this WeakReference<object> referen
 			return reference.TryGetTarget(out _);
 		}
 	}
-}
+}

src/Controls/tests/DeviceTests/Elements/NavigationPage/NavigationPageTests.cs

@@ -352,8 +352,8 @@ await CreateHandlerAndAddToWindow<WindowHandlerStub>(new Window(navPage), async
 		}
 
 		[Fact(DisplayName = "Does Not Leak"
-#if WINDOWS || ANDROID
-			, Skip = "Failing https://github.com/dotnet/maui/issues/27411"
+#if WINDOWS
+			, Skip = "Failing"
 #endif
 		)]
 		public async Task DoesNotLeak()

src/Controls/tests/TestCases.HostApp/Issues/Bugzilla/Bugzilla40955.cs

@@ -161,6 +161,8 @@ public _409555_Page2()
 
 	public class _409555_Page3 : ContentPage
 	{
+		Label successLabel;
+
 		public _409555_Page3()
 		{
 			Title = Page3Title;
@@ -176,20 +178,31 @@ public _409555_Page3()
 				Command = new Command(async () => await DisplayAlertAsync("Alert", Success, "Ok"))
 			});
 
-			var successLabel = new Label();
+			successLabel = new Label();
 			Content = new StackLayout
 			{
 				Children =
 				{
-					lbl
+					lbl,
+					successLabel
 				}
 			};
 		}
 
-		protected override void OnAppearing()
+		protected override async void OnAppearing()
 		{
 			base.OnAppearing();
-			GarbageCollectionHelper.Collect();
+
+			// Try multiple GC cycles to ensure finalizers run
+			// Android GC can be less aggressive, so we need to retry
+			for (int i = 0; i < 10 && string.IsNullOrEmpty(Success); i++)
+			{
+				GarbageCollectionHelper.Collect();
+				await Task.Delay(100);
+			}
+
+			successLabel.Text = Success;
+			successLabel.AutomationId = Success;
 		}
 	}
 }

src/Controls/tests/TestCases.HostApp/Issues/Bugzilla/Bugzilla42329.cs

@@ -190,10 +190,18 @@ public _42329_Page3()
 			};
 		}
 
-		protected override void OnAppearing()
+		protected override async void OnAppearing()
 		{
 			base.OnAppearing();
-			GarbageCollectionHelper.Collect();
+
+			// Try multiple GC cycles to ensure finalizers run
+			// Android GC can be less aggressive, so we need to retry
+			for (int i = 0; i < 10 && string.IsNullOrEmpty(Success); i++)
+			{
+				GarbageCollectionHelper.Collect();
+				await Task.Delay(100);
+			}
+
 			otherLabel.Text = Success;
 			otherLabel.AutomationId = Success;
 		}

src/Controls/tests/TestCases.HostApp/Issues/Bugzilla/Bugzilla44166.cs

@@ -14,9 +14,15 @@ protected override void Init()
 		goButton.Clicked += (sender, args) => Application.Current.MainPage = new _44166MDP();
 
 		var gcButton = new Button { Text = "GC", AutomationId = "GC" };
-		gcButton.Clicked += (sender, args) =>
+		gcButton.Clicked += async (sender, args) =>
 		{
-			GarbageCollectionHelper.Collect();
+			// Try multiple GC cycles to ensure finalizers run
+			// Android GC can be less aggressive, so we need to retry
+			for (int i = 0; i < 10; i++)
+			{
+				GarbageCollectionHelper.Collect();
+				await Task.Delay(100);
+			}
 
 			if (_44166MDP.Counter > 0)
 			{

src/Controls/tests/TestCases.HostApp/Issues/Issue5555.cs

@@ -1,6 +1,6 @@
 namespace Maui.Controls.Sample.Issues
 {
-	[Issue(IssueTracker.None, 5555, "Memory leak when SwitchCell or EntryCell", PlatformAffected.iOS)]
+	[Issue(IssueTracker.None, 5555, "Memory leak when SwitchCell or EntryCell", PlatformAffected.All)]
 	public class Issue5555 : NavigationPage
 	{
 		public Issue5555() : base(new TestPage())

src/Controls/tests/TestCases.HostApp/Utils/GarbageCollectionHelper.cs

@@ -7,7 +7,7 @@ public static void Collect()
 			GC.Collect();
 			GC.WaitForPendingFinalizers();
 
-			GC.Collect();
+			GC.Collect(2);
 			GC.WaitForPendingFinalizers();
 		}
 

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Bugzilla/Bugzilla40955.cs

@@ -23,9 +23,6 @@ public Bugzilla40955(TestDevice testDevice) : base(testDevice)
 	public override string Issue => "Memory leak with FormsAppCompatActivity and NavigationPage";
 
 	[Test]
-#if ANDROID
-	[Ignore("Failing on net10 https://github.com/dotnet/maui/issues/27411")]
-#endif
 	[Category(UITestCategories.Performance)]
 	public void MemoryLeakInFormsAppCompatActivity()
 	{

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Bugzilla/Bugzilla42329.cs

@@ -19,9 +19,6 @@ public Bugzilla42329(TestDevice testDevice) : base(testDevice)
 	public override string Issue => "ListView in Frame and FormsAppCompatActivity Memory Leak";
 
 	[Test]
-#if ANDROID
-	[Ignore("Failing on net10 https://github.com/dotnet/maui/issues/27411")]
-#endif
 	[Category(UITestCategories.ListView)]
 	public async Task MemoryLeakB42329()
 	{

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Bugzilla/Bugzilla44166.cs

@@ -14,9 +14,6 @@ public Bugzilla44166(TestDevice testDevice) : base(testDevice)
 	public override string Issue => "FlyoutPage instances do not get disposed upon GC";
 
 	[Test]
-#if ANDROID
-	[Ignore("Failing on net10 https://github.com/dotnet/maui/issues/27411")]
-#endif
 	[Category(UITestCategories.Performance)]
 	public void Bugzilla44166Test()
 	{