[Android] [ShellHandler] Extend existing device tests to cover both Renderer and Handler code paths

src/Controls/src/Core/Platform/Android/BottomNavigationViewUtils.cs

@@ -68,12 +68,13 @@ internal static Task SetupMenuItem(
 			int currentIndex,
 			BottomNavigationView bottomView,
 			IMauiContext mauiContext,
-			out IMenuItem menuItem)
+			out IMenuItem menuItem,
+			Action<IMenuItem> onIconLoaded = null)
 		{
 			Task returnValue;
 			using var title = new Java.Lang.String(item.title);
 			menuItem = menu.Add(0, index, 0, title);
-			returnValue = SetMenuItemIcon(menuItem, item.icon, mauiContext);
+			returnValue = SetMenuItemIcon(menuItem, item.icon, mauiContext, onIconLoaded);
 			UpdateEnabled(item.tabEnabled, menuItem);
 			if (index == currentIndex)
 			{
@@ -90,7 +91,8 @@ internal static async void SetupMenu(
 			List<(string title, ImageSource icon, bool tabEnabled)> items,
 			int currentIndex,
 			BottomNavigationView bottomView,
-			IMauiContext mauiContext)
+			IMauiContext mauiContext,
+			Action<IMenuItem> onIconLoaded = null)
 		{
 			maxBottomItems = Math.Min(maxBottomItems, MaxBottomNavigationItems);
 			Context context = mauiContext.Context;
@@ -112,43 +114,75 @@ internal static async void SetupMenu(
 
 				IMenuItem menuItem;
 				if (i >= menu.Size())
-					loadTasks.Add(SetupMenuItem(item, menu, i, currentIndex, bottomView, mauiContext, out menuItem));
+					loadTasks.Add(SetupMenuItem(item, menu, i, currentIndex, bottomView, mauiContext, out menuItem, onIconLoaded));
 				else
 				{
 					menuItem = menu.GetItem(i);
 					if (menuItem.ItemId != i)
 					{
 						menu.RemoveItem(menuItem.ItemId);
-						loadTasks.Add(SetupMenuItem(item, menu, i, currentIndex, bottomView, mauiContext, out menuItem));
+						loadTasks.Add(SetupMenuItem(item, menu, i, currentIndex, bottomView, mauiContext, out menuItem, onIconLoaded));
 					}
 					else
 					{
 						SetMenuItemTitle(menuItem, item.title);
-						loadTasks.Add(SetMenuItemIcon(menuItem, item.icon, mauiContext));
+						loadTasks.Add(SetMenuItemIcon(menuItem, item.icon, mauiContext, onIconLoaded));
+						// Reapply enabled/selected state since this IMenuItem is being reused, not recreated.
+						UpdateEnabled(item.tabEnabled, menuItem);
+						if (i == currentIndex)
+						{
+							menuItem.SetChecked(true);
+							bottomView.SelectedItemId = i;
+						}
 					}
 				}
 
 				menuItems.Add(menuItem);
 			}
 
 			var menuSize = menu.Size();
+			IMenuItem moreMenuItem = null;
 			if (showMore && menu.GetItem(menuSize - 1).ItemId != MoreTabId)
 			{
 				var moreString = context.Resources.GetText(Resource.String.overflow_tab_title);
 				if (menuSize == maxBottomItems)
 					menu.RemoveItem(menu.GetItem(menuSize - 1).ItemId);
-				var menuItem = menu.Add(0, MoreTabId, 0, moreString);
-				menuItems.Add(menuItem);
+				moreMenuItem = menu.Add(0, MoreTabId, 0, moreString);
+				menuItems.Add(moreMenuItem);
 
-				menuItem.SetIcon(Resource.Drawable.abc_ic_menu_overflow_material);
-				if (currentIndex >= maxBottomItems - 1)
-					menuItem.SetChecked(true);
+				moreMenuItem.SetIcon(Resource.Drawable.abc_ic_menu_overflow_material);
+			}
+			else if (showMore)
+			{
+				// The More item already exists (reused, not recreated) — still need to
+				// reapply its selected state below in case currentIndex has changed.
+				moreMenuItem = menu.GetItem(menuSize - 1);
+			}
+
+			if (moreMenuItem is not null && currentIndex >= maxBottomItems - 1)
+			{
+				// Use SetChecked only — setting SelectedItemId would trigger ShowMoreBottomSheet().
+				moreMenuItem.SetChecked(true);
 			}
 
 			bottomView.SetShiftMode(false, false);
 
 			if (loadTasks.Count > 0)
-				await Task.WhenAll(loadTasks);
+			{
+				try
+				{
+					await Task.WhenAll(loadTasks);
+				}
+				catch (Exception ex)
+				{
+					// SetupMenu is async void — an unhandled exception here would crash
+					// the app. SetMenuItemIcon itself no longer swallows exceptions so
+					// its other caller (ShellItemRenderer.UpdateShellSectionIcon, via
+					// FireAndForget) can still observe/log a faulted Task; this catch
+					// only protects SetupMenu's own async-void boundary.
+					System.Diagnostics.Debug.WriteLine($"SetupMenu: one or more icon loads failed: {ex}");
+				}
+			}
 		}
 
 		internal static void SetMenuItemTitle(IMenuItem menuItem, string title)
@@ -157,14 +191,31 @@ internal static void SetMenuItemTitle(IMenuItem menuItem, string title)
 			menuItem.SetTitle(jTitle);
 		}
 
-		internal static async Task SetMenuItemIcon(IMenuItem menuItem, ImageSource source, IMauiContext context)
+		// Records which ImageSource each reused IMenuItem is currently supposed to show, so a
+		// slower, stale load (from before the item was repurposed for a different tab) can
+		// detect it's been superseded and skip applying its now-outdated result.
+		static readonly ConditionalWeakTable<IMenuItem, ImageSource> s_pendingIconSource = new();
+
+		internal static async Task SetMenuItemIcon(IMenuItem menuItem, ImageSource source, IMauiContext context, Action<IMenuItem> onIconLoaded = null)
 		{
 			if (!menuItem.IsAlive())
 				return;
 
+			s_pendingIconSource.AddOrUpdate(menuItem, source);
+
 			if (source is null)
+			{
+				// Clear any stale icon left on this (possibly reused) menu item.
+				menuItem.SetIcon(null);
+				onIconLoaded?.Invoke(menuItem);
 				return;
+			}
 
+			// Exceptions are intentionally allowed to propagate here (not swallowed) so
+			// callers can observe/log failures via the returned Task — e.g. the legacy
+			// ShellItemRenderer.UpdateShellSectionIcon relies on FireAndForget's error
+			// handler seeing a faulted Task. SetupMenu (the other caller) guards its own
+			// async-void boundary separately when awaiting these tasks.
 			var services = context.Services;
 			var provider = services.GetRequiredService<IImageSourceServiceProvider>();
 			var imageSourceService = provider.GetRequiredImageSourceService(source);
@@ -173,9 +224,14 @@ internal static async Task SetMenuItemIcon(IMenuItem menuItem, ImageSource sourc
 				source,
 				context.Context);
 
-			if (menuItem.IsAlive())
+			// Skip applying if this menu item has since been repurposed for a different
+			// source (i.e. a newer SetMenuItemIcon call updated the pending source above).
+			if (menuItem.IsAlive() && s_pendingIconSource.TryGetValue(menuItem, out var pending) && ReferenceEquals(pending, source))
 			{
 				menuItem.SetIcon(result?.Value);
+				// Let the caller reapply per-item icon tint (e.g. to preserve a
+				// FontImageSource's own Color) now that the drawable is installed.
+				onIconLoaded?.Invoke(menuItem);
 			}
 		}
 

src/Controls/src/Core/Platform/Android/TabbedViewManager.cs

@@ -744,7 +744,9 @@ internal void UpdateSwipePaging()
             var tab = Element.Tabs[i];
             // ITab.Icon is IImageSource; convert to ImageSource if possible for BottomNavigationViewUtils
             var icon = tab.Icon as ImageSource;
-            items.Add((tab.Title, icon, tab.IsEnabled));
+            // Fallback for null/whitespace Title to avoid a blank bottom tab label.
+            var title = !string.IsNullOrWhiteSpace(tab.Title) ? tab.Title : $"Tab {i + 1}";
+            items.Add((title, icon, tab.IsEnabled));
         }
 
         return items;
@@ -758,11 +760,13 @@ internal virtual void SetupBottomNavigationView()
         }
 
         var menu = _bottomNavigationView.Menu;
-        menu.Clear();
 
         var tabs = Element.Tabs;
         if (tabs is null || tabs.Count == 0)
         {
+            menu.Clear();
+            _bottomNavigationView.SetOnItemSelectedListener(null);
+            _bottomNavigationView.SetOnItemReselectedListener(null);
             return;
         }
 
@@ -776,43 +780,21 @@ internal virtual void SetupBottomNavigationView()
 
         _bottomNavigationView.Visibility = ViewStates.Visible;
 
-        int maxItems = Math.Min(_bottomNavigationView.MaxItemCount, BottomNavigationViewUtils.MaxBottomNavigationItems);
-        bool showMore = tabs.Count > maxItems;
-        int end = showMore ? maxItems - 1 : tabs.Count;
-
-        for (int i = 0; i < end; i++)
-        {
-            var tab = tabs[i];
-            var title = !string.IsNullOrWhiteSpace(tab.Title) ? tab.Title : $"Tab {i + 1}";
-            var menuItem = menu.Add(0, i, i, title);
-
-            if (menuItem is null)
-            {
-                continue;
-            }
-
-            if (!tab.IsEnabled)
-            {
-                menuItem.SetEnabled(false);
-            }
-
-            LoadBottomNavIconAsync(menuItem, tab);
-        }
-
-        // Add "More" overflow item if needed
-        if (showMore)
-        {
-            var moreItem = menu.Add(0, BottomNavigationViewUtils.MoreTabId, maxItems - 1, "More");
-            moreItem?.SetIcon(Resource.Drawable.abc_ic_menu_overflow_material);
-        }
+        // Use BottomNavigationViewUtils.SetupMenu which does incremental in-place updates
+        // (reuses existing IMenuItem objects at unchanged positions, preserving identity).
+        // This matches the renderer's ShellItemRenderer.SetupMenu behavior and avoids
+        // menu.Clear() which destroys all IMenuItem references on every tab add/remove.
+        var items = CreateTabList();
 
-        // Set initial selection using pre-computed index (avoids wrapper comparison issues)
         var currentIndex = Element.CurrentTabIndex;
-        if (currentIndex >= 0 && currentIndex < tabs.Count)
-        {
-            int targetId = currentIndex >= end ? BottomNavigationViewUtils.MoreTabId : currentIndex;
-            _bottomNavigationView.SelectedItemId = targetId;
-        }
+        BottomNavigationViewUtils.SetupMenu(
+            menu,
+            _bottomNavigationView.MaxItemCount,
+            items,
+            currentIndex,
+            _bottomNavigationView,
+            _context,
+            onIconLoaded: menuItem => SetupBottomNavigationViewIconColor(menuItem.ItemId, menuItem));
 
         _bottomNavigationView.SetShiftMode(false, false);
 
@@ -832,23 +814,20 @@ async void LoadBottomNavIconAsync(IMenuItem menuItem, ITab tab)
     {
         try
         {
-            if (tab.Icon is not ImageSource icon)
-            {
-                return;
-            }
-
-            var result = await icon.GetPlatformImageAsync(_context);
-            if (result?.Value is not null && menuItem.IsAlive())
-            {
-                menuItem.SetIcon(result.Value);
-
+            // Route through BottomNavigationViewUtils.SetMenuItemIcon instead of loading
+            // the icon directly here. SetMenuItemIcon guards against a reused IMenuItem
+            // being repurposed (by SetupMenu) for a different tab while this load is still
+            // in flight -- without that guard, this call could win a race against a newer
+            // SetupMenu-driven icon load and overwrite the wrong tab's icon.
+            await BottomNavigationViewUtils.SetMenuItemIcon(
+                menuItem,
+                tab.Icon as ImageSource,
+                _context,
                 // Apply per-item icon tint after loading so that:
                 // 1. FontImageSource with explicit Color shows its own color (tint cleared)
                 // 2. FontImageSource without Color gets SelectedTabColor/UnselectedTabColor tint
                 // Without this, the global ItemIconTintList overrides baked-in colors.
-                var tabIndex = menuItem.ItemId;
-                SetupBottomNavigationViewIconColor(tabIndex, menuItem);
-            }
+                onIconLoaded: loadedMenuItem => SetupBottomNavigationViewIconColor(loadedMenuItem.ItemId, loadedMenuItem));
         }
         catch (Exception ex)
         {

src/Controls/tests/DeviceTests/ControlsHandlerTestBase.Android.cs

@@ -211,7 +211,7 @@ public bool IsNavigationBarVisible(IMauiContext mauiContext)
 					.LayoutParameters?.Height > 0;
 		}
 
-		protected bool IsBackButtonVisible(IElementHandler handler)
+		protected virtual bool IsBackButtonVisible(IElementHandler handler)
 		{
 			if (GetPlatformToolbar(handler)?.NavigationIcon is DrawerArrowDrawable dad)
 				return dad.Progress == 1;

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

@@ -29,9 +29,10 @@ namespace Microsoft.Maui.DeviceTests
 #if ANDROID || IOS || MACCATALYST
 	[Collection(ControlsHandlerTestBase.RunInNewWindowCollection)]
 #endif
+	[Trait(RendererHandlerVariant.TraitName, RendererHandlerVariant.AndroidShellRenderer)] // See RendererHandlerVariant.cs
 	public partial class ModalTests : ControlsHandlerTestBase
 	{
-		void SetupBuilder()
+		protected virtual void SetupBuilder()
 		{
 			EnsureHandlerCreated(builder =>
 			{

src/Controls/tests/DeviceTests/Elements/Shell/RendererHandlerVariant.cs

@@ -0,0 +1,14 @@
+namespace Microsoft.Maui.DeviceTests
+{
+	/// <summary>
+	/// Trait key/values for Android Shell Renderer/Handler test variants so that, on Android only,
+	/// xUnitCustomizations.cs can prefix their DisplayName as "[Renderer]"/"[Handler]".
+	/// Also reused by Modal/Window tests, which share the same Android Renderer/Handler reuse logic as Shell.
+	/// </summary>
+	public static class RendererHandlerVariant
+	{
+		public const string TraitName = "Variant";
+		public const string AndroidShellRenderer = "Renderer";
+		public const string AndroidShellHandler = "Handler";
+	}
+}

src/Controls/tests/DeviceTests/Elements/Shell/ShellFlyoutTests.Android.cs

@@ -1,6 +1,7 @@
 using System.Threading.Tasks;
 using AndroidX.DrawerLayout.Widget;
 using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Platform.Compatibility;
 using Xunit;
 
 namespace Microsoft.Maui.DeviceTests
@@ -15,18 +16,21 @@ await RunShellTest(shell =>
 			{
 				shell.FlyoutContent = new VerticalStackLayout() { new Label() { Text = "Flyout Content" } };
 			},
-			async (shell, handler) =>
+			async shell =>
 			{
+#if ANDROID || IOS || MACCATALYST
+				var shellContext = (IShellContext)shell.Handler;
+#endif
 				// 1. Set FlyoutIsPresented=true to make the Shell Flyout visible.
 				shell.FlyoutIsPresented = true;
 
-				var dl = GetDrawerLayout(handler) as DrawerLayout;
+				var dl = GetDrawerLayout(shellContext) as DrawerLayout;
 				Assert.NotNull(dl);
 
 				await AssertionExtensions.AssertEventually(() =>
 				{
 					// 2. Check that the Flyout has size.
-					var flyoutFrame = GetFlyoutFrame(handler);
+					var flyoutFrame = GetFlyoutFrame(shellContext);
 					return flyoutFrame.Width > 0 && flyoutFrame.Height > 0 && dl.IsOpen;
 				});
 			});