[Android] Fix page not disposed on Shell replace navigation

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

@@ -222,6 +222,21 @@ void Destroy()
 			_shellPageContainer = null;
 		}
 
+		internal void DisposePage()
+		{
+			if (_destroyed)
+			{
+				return;
+			}
+			Destroy();
+
+			if (_page is not null)
+			{
+				_page.DisconnectHandlers();
+				_page = null;
+			}
+		}
+
 		protected override void Dispose(bool disposing)
 		{
 			if (_disposed)

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

@@ -167,6 +167,11 @@ protected virtual Task<bool> HandleFragmentUpdate(ShellNavigationSource navSourc
 						if (ChildFragmentManager.Contains(removeFragment.Fragment) && !isForCurrentTab && removeFragment != _currentFragment)
 							RemoveFragment(removeFragment.Fragment);
 						_fragmentMap.Remove(page);
+
+						if (removeFragment is ShellContentFragment shellFragment)
+						{
+							shellFragment.DisposePage();
+						}
 					}
 
 					if (!isForCurrentTab && removeFragment != _currentFragment)

src/Controls/tests/TestCases.HostApp/Issues/Issue25134.cs

@@ -0,0 +1,114 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 25134, "Shell retains page references when replacing a page", PlatformAffected.Android)]
+public class Issue25134 : Shell
+{
+    public Issue25134()
+    {
+        var mainContent = new ShellContent
+        {
+            ContentTemplate = new DataTemplate(() => new Issue25134InitialPage()),
+            Title = "Initial",
+            Route = "initial"
+        };
+
+        Items.Add(mainContent);
+        Routing.RegisterRoute("Issue25134_child", typeof(Issue25134ChildPage));
+        Routing.RegisterRoute("Issue25134_replace", typeof(Issue25134ReplacePage));
+    }
+}
+
+public class Issue25134InitialPage : ContentPage
+{
+    public WeakReference<Page> ChildPageReference { get; set; }
+
+    public Issue25134InitialPage()
+    {
+        Title = "Initial Page";
+
+        var goToChildButton = new Button
+        {
+            Text = "Go to child page",
+            AutomationId = "goToChildPage",
+            VerticalOptions = LayoutOptions.Start,
+            Command = new Command(() => Shell.Current.GoToAsync("Issue25134_child"))
+        };
+
+        Content = new VerticalStackLayout
+        {
+            goToChildButton
+        };
+    }
+}
+
+public class Issue25134ChildPage : ContentPage
+{
+    public Issue25134ChildPage()
+    {
+        Title = "Child Page";
+
+        var button = new Button
+        {
+            Text = "Replace",
+            AutomationId = "replace",
+            VerticalOptions = LayoutOptions.Start,
+            Command = new Command(() => Shell.Current.GoToAsync("../Issue25134_replace"))
+        };
+
+        Content = new VerticalStackLayout
+        {
+            button
+        };
+    }
+
+    protected override void OnParentSet()
+    {
+        base.OnParentSet();
+
+        if (Parent is ShellSection section)
+        {
+            var initialPage = (section.CurrentItem as IShellContentController).Page as Issue25134InitialPage;
+            initialPage!.ChildPageReference = new WeakReference<Page>(this);
+        }
+    }
+}
+
+public class Issue25134ReplacePage : ContentPage
+{
+    public Issue25134ReplacePage()
+    {
+        Title = "Replace Page";
+
+        Button checkRefButton = null;
+        checkRefButton = new Button
+        {
+            Text = "Check reference",
+            AutomationId = "checkReference",
+            VerticalOptions = LayoutOptions.Start,
+            Command = new Command(async () =>
+            {
+                GC.Collect();
+                GC.WaitForPendingFinalizers();
+                await Task.Yield();
+
+                var section = (ShellSection)Parent;
+                var initialPage = (Issue25134InitialPage)(section.CurrentItem as IShellContentController).Page;
+                checkRefButton.Text = initialPage.ChildPageReference.TryGetTarget(out var page) ? "alive" : "gone";
+            })
+        };
+
+        var backButton = new Button
+        {
+            Text = "Go back",
+            AutomationId = "goBack",
+            VerticalOptions = LayoutOptions.Start,
+            Command = new Command(() => Shell.Current.GoToAsync(".."))
+        };
+
+        Content = new VerticalStackLayout
+        {
+            checkRefButton,
+            backButton
+        };
+    }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue25134.cs

@@ -0,0 +1,27 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue25134 : _IssuesUITest
+{
+    public Issue25134(TestDevice testDevice) : base(testDevice)
+    {
+    }
+
+    public override string Issue => "Shell retains page references when replacing a page";
+
+    [Test]
+    [Category(UITestCategories.Shell)]
+    public void ShellReplaceDisposesPage()
+    {
+        App.WaitForElement("goToChildPage");
+        App.Tap("goToChildPage");
+        App.WaitForElement("replace");
+        App.Tap("replace");
+        var button = App.WaitForElement("checkReference");
+        App.Tap("checkReference");
+        Assert.That(button.GetText(), Is.EqualTo("gone"));
+    }
+}