Fix issues with shell and pushing modals early

src/Controls/src/Core/HandlerImpl/Window/Window.Impl.cs

@@ -419,6 +419,8 @@ void SendWindowAppearing()
 		{
 			if (Navigation.ModalStack.Count == 0)
 				Page?.SendAppearing();
+			else if (Page is Shell shell)
+				shell.SendAppearing();
 		}
 
 		void SendWindowDisppearing()

src/Controls/src/Core/Platform/ModalNavigationManager/ModalNavigationManager.cs

@@ -245,13 +245,17 @@ public async Task PushModalAsync(Page modal, bool animated)
 			{
 				if (ModalStack.Count == 0)
 				{
-					modal.NavigationProxy.Inner = _window.Navigation;
+					if (modal.NavigationProxy.Inner is null)
+						modal.NavigationProxy.Inner = _window.Navigation;
+
 					await PushModalPlatformAsync(modal, animated);
 				}
 				else
 				{
 					await PushModalPlatformAsync(modal, animated);
-					modal.NavigationProxy.Inner = _window.Navigation;
+
+					if (modal.NavigationProxy.Inner is null)
+						modal.NavigationProxy.Inner = _window.Navigation;
 				}
 			}
 

src/Controls/src/Core/Shell/NavigableElement.cs

@@ -88,7 +88,21 @@ protected override void OnParentSet()
 
 			if (navProxy != null)
 			{
-				NavigationProxy.Inner = navProxy.NavigationProxy;
+				// Modal navigation needs to all proxy through Shell
+				// So, when the modal page is parented to the window
+				// we make sure to set the NavProxy on the modal page to the
+				// Shell wrapper
+				if (Parent is Window w &&
+					w.Page is Shell shell &&
+					this is not Shell)
+				{
+					if (NavigationProxy.Inner is not Shell.ShellNavigationImplWrapper)
+						NavigationProxy.Inner = new Shell.ShellNavigationImplWrapper(navProxy.NavigationProxy, shell.Navigation);
+				}
+				else
+				{
+					NavigationProxy.Inner = navProxy.NavigationProxy;
+				}
 			}
 			else
 			{

src/Controls/src/Core/Shell/Shell.cs

@@ -1710,24 +1710,28 @@ protected override async Task OnPushModal(Page modal, bool animated)
 
 				await base.OnPushModal(modal, animated);
 
-				modal.NavigationProxy.Inner = new NavigationImplWrapper(modal.NavigationProxy.Inner, this);
+				if (modal.NavigationProxy.Inner is not ShellNavigationImplWrapper &&
+					modal.NavigationProxy.Inner is not null)
+				{
+					modal.NavigationProxy.Inner = new ShellNavigationImplWrapper(modal.NavigationProxy.Inner, this);
+				}
 			}
+		}
 
-			class NavigationImplWrapper : NavigationProxy
-			{
-				readonly INavigation _shellProxy;
+		internal class ShellNavigationImplWrapper : NavigationProxy
+		{
+			readonly INavigation _shellProxy;
 
-				public NavigationImplWrapper(INavigation proxy, INavigation shellProxy)
-				{
-					Inner = proxy;
-					_shellProxy = shellProxy;
+			public ShellNavigationImplWrapper(INavigation proxy, INavigation shellProxy)
+			{
+				Inner = proxy;
+				_shellProxy = shellProxy;
 
-				}
+			}
 
-				protected override Task<Page> OnPopModal(bool animated) => _shellProxy.PopModalAsync(animated);
+			protected override Task<Page> OnPopModal(bool animated) => _shellProxy.PopModalAsync(animated);
 
-				protected override Task OnPushModal(Page modal, bool animated) => _shellProxy.PushModalAsync(modal, animated);
-			}
+			protected override Task OnPushModal(Page modal, bool animated) => _shellProxy.PushModalAsync(modal, animated);
 		}
 	}
 }

src/Controls/src/Core/Shell/ShellSection.cs

@@ -53,10 +53,12 @@ Page IShellSectionController.PresentedPage
 			{
 				if (Navigation.ModalStack.Count > 0)
 				{
-					if (Navigation.ModalStack[Navigation.ModalStack.Count - 1] is NavigationPage np)
+					var currentModalPage = Navigation.ModalStack[Navigation.ModalStack.Count - 1];
+
+					if (currentModalPage is NavigationPage np)
 						return np.Navigation.NavigationStack[np.Navigation.NavigationStack.Count - 1];
 
-					return Navigation.ModalStack[0];
+					return currentModalPage;
 				}
 
 				if (_navStack.Count > 1)

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

@@ -12,6 +12,55 @@ namespace Microsoft.Maui.Controls.Core.UnitTests
 
 	public class ShellModalTests : ShellTestBase
 	{
+		[Fact]
+		public async Task AppearingAndDisappearingFireWhenShellCreatedBeforeWindow()
+		{
+			var windowPage = new ContentPage();
+			var modalPage1 = new ContentPage();
+			var modalPage2 = new ContentPage();
+
+			int modal1Appearing = 0;
+			int modal1Disappearing = 0;
+			int modal2Appearing = 0;
+			int modal2Disappearing = 0;
+			int windowAppearing = 0;
+			int windowDisappearing = 0;
+			int shellAppearing = 0;
+
+			modalPage1.Appearing += (_, _) => modal1Appearing++;
+			modalPage1.Disappearing += (_, _) => modal1Disappearing++;
+
+			modalPage2.Appearing += (_, _) => modal2Appearing++;
+			modalPage2.Disappearing += (_, _) => modal2Disappearing++;
+
+			windowPage.Appearing += (_, _) => windowAppearing++;
+			windowPage.Disappearing += (_, _) => windowDisappearing++;
+
+			var shell = new Shell();
+			shell.Appearing += (_, _) => shellAppearing++;
+
+			shell.Items.Add(new ShellContent { Content = windowPage });
+
+			await windowPage.Navigation.PushModalAsync(modalPage1);
+			await windowPage.Navigation.PushModalAsync(modalPage2);
+
+			var window = new TestWindow(shell);
+
+			await windowPage.Navigation.PopModalAsync();
+			await windowPage.Navigation.PopModalAsync();
+
+			Assert.Equal(1, shellAppearing);
+
+			Assert.Equal(1, modal1Appearing);
+			Assert.Equal(1, modal1Disappearing);
+
+			Assert.Equal(1, modal2Appearing);
+			Assert.Equal(1, modal2Disappearing);
+
+			Assert.Equal(1, windowAppearing);
+			Assert.Equal(0, windowDisappearing);
+		}
+
 		[Fact]
 		public async Task AppearingAndDisappearingFireOnMultipleModals()
 		{

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

@@ -1237,6 +1237,34 @@ public void GetCurrentPageOnInit()
 			Assert.NotNull(page);
 		}
 
+		[Fact]
+		public async Task CurrentPageReturnsCorrectModalPage()
+		{
+			var windowPage = new ContentPage();
+			var modalPage1 = new ContentPage();
+			var modalPage2 = new ContentPage();
+
+			var shell = new TestShell(new ShellContent { Content = windowPage });
+
+			await windowPage.Navigation.PushModalAsync(modalPage1);
+			await windowPage.Navigation.PushModalAsync(modalPage2);
+
+			Assert.Equal(shell.Window.Navigation.ModalStack[0], modalPage1);
+			Assert.Equal(shell.Window.Navigation.ModalStack[1], modalPage2);
+			Assert.Equal(2, shell.Window.Navigation.ModalStack.Count);
+			Assert.Equal(modalPage2, shell.CurrentPage);
+
+			await windowPage.Navigation.PopModalAsync();
+
+			Assert.Equal(shell.Window.Navigation.ModalStack[0], modalPage1);
+			Assert.Equal(1, shell.Window.Navigation.ModalStack.Count);
+			Assert.Equal(modalPage1, shell.CurrentPage);
+
+			await windowPage.Navigation.PopModalAsync();
+
+			Assert.Equal(windowPage, shell.CurrentPage);
+		}
+
 		[Fact]
 		public async Task HotReloadStaysOnActiveItem()
 		{

src/Controls/tests/DeviceTests/Elements/Modal/ModalTests.cs

@@ -35,28 +35,70 @@ void SetupBuilder()
 			{
 				builder.ConfigureMauiHandlers(handlers =>
 				{
-					handlers.AddHandler(typeof(Toolbar), typeof(ToolbarHandler));
 					handlers.AddHandler(typeof(NavigationPage), typeof(NavigationViewHandler));
 					handlers.AddHandler(typeof(FlyoutPage), typeof(FlyoutViewHandler));
 					handlers.AddHandler(typeof(TabbedPage), typeof(TabbedViewHandler));
 					handlers.AddHandler<Page, PageHandler>();
 					handlers.AddHandler<Window, WindowHandlerStub>();
 
+					SetupShellHandlers(handlers);
 					handlers.AddHandler(typeof(Controls.Shell), typeof(ShellHandler));
-					handlers.AddHandler<Layout, LayoutHandler>();
-					handlers.AddHandler<Entry, EntryHandler>();
-					handlers.AddHandler<Image, ImageHandler>();
-					handlers.AddHandler<Label, LabelHandler>();
-					handlers.AddHandler<Toolbar, ToolbarHandler>();
-#if WINDOWS
-					handlers.AddHandler<ShellItem, ShellItemHandler>();
-					handlers.AddHandler<ShellSection, ShellSectionHandler>();
-					handlers.AddHandler<ShellContent, ShellContentHandler>();
-#endif
 				});
 			});
 		}
 
+		[Fact]
+		public async Task AppearingAndDisappearingFireWhenShellCreatedBeforeWindow()
+		{
+			SetupBuilder();
+			var windowPage = new ContentPage();
+			var modalPage1 = new ContentPage();
+			var modalPage2 = new ContentPage();
+			var shell = new Shell();
+
+			int modal1Appearing = 0;
+			int modal1Disappearing = 0;
+			int modal2Appearing = 0;
+			int modal2Disappearing = 0;
+			int windowAppearing = 0;
+			int windowDisappearing = 0;
+			int shellAppearing = 0;
+
+			shell.Appearing += (_, _) => shellAppearing++;
+			modalPage1.Appearing += (_, _) => modal1Appearing++;
+			modalPage1.Disappearing += (_, _) => modal1Disappearing++;
+
+			modalPage2.Appearing += (_, _) => modal2Appearing++;
+			modalPage2.Disappearing += (_, _) => modal2Disappearing++;
+
+			windowPage.Appearing += (_, _) => windowAppearing++;
+			windowPage.Disappearing += (_, _) => windowDisappearing++;
+
+			shell.Items.Add(new ShellContent { Content = windowPage });
+
+			await windowPage.Navigation.PushModalAsync(modalPage1);
+			await windowPage.Navigation.PushModalAsync(modalPage2);
+
+			await CreateHandlerAndAddToWindow<IWindowHandler>(new Window(shell),
+				async (_) =>
+				{
+					await windowPage.Navigation.PopModalAsync();
+					await windowPage.Navigation.PopModalAsync();
+				});
+
+			// These values should match up with AppearingAndDisappearingFireWhenShellCreatedBeforeWindow
+			// in the ShellModalTests on the unit tests
+			Assert.Equal(1, modal1Appearing);
+			Assert.Equal(1, modal1Disappearing);
+
+			Assert.Equal(1, modal2Appearing);
+			Assert.Equal(1, modal2Disappearing);
+
+			Assert.Equal(1, windowAppearing);
+			Assert.Equal(0, windowDisappearing);
+		}
+
+
 		[Theory]
 		[InlineData(true)]
 		[InlineData(false)]