[Android] Crash removing item from CarouselView - fix

src/Controls/samples/Controls.Sample.UITests/Issues/Issue19786.xaml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue19786">
+    <StackLayout>
+        <CarouselView Position="{Binding Position}" HeightRequest="200" ItemsSource="{Binding Items}">
+            <CarouselView.ItemTemplate>
+                <DataTemplate>
+                    <Frame Margin="10" WidthRequest="200" BackgroundColor="Red">
+                        <Label Text="{Binding .}"/>
+                    </Frame>
+                </DataTemplate>
+            </CarouselView.ItemTemplate>
+        </CarouselView>
+
+        <Grid ColumnDefinitions="*,*,*">
+            <Button AutomationId="addItemButton" Grid.Column="0" Text="Add item" Command="{Binding AddItemCommand}"/>
+            <Button AutomationId="goToNextItemButton" Grid.Column="1" Text="Go to next item" Command="{Binding GoToNextItemCommand}"/>
+            <Button AutomationId="removeLastItemButton" Grid.Column="2" Text="Remove last item" Command="{Binding RemoveItemCommand}"/>
+        </Grid>
+    </StackLayout>
+</ContentPage>

src/Controls/samples/Controls.Sample.UITests/Issues/Issue19786.xaml.cs

@@ -0,0 +1,61 @@
+using System.Collections.ObjectModel;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 19786, "[Android] Crash removing item from CarouselView", PlatformAffected.All)]
+	public partial class Issue19786 : ContentPage
+	{
+		public Command AddItemCommand { get; set; }
+		public Command RemoveItemCommand { get; set; }
+		public Command GoToNextItemCommand { get; set; }
+
+		private int _position;
+		public int Position
+		{
+			get => _position;
+			set
+			{
+				_position = value;
+				OnPropertyChanged();
+			}
+		}
+
+		private ObservableCollection<string> _items = new();
+		public ObservableCollection<string> Items
+		{
+			get => _items;
+			set
+			{
+				_items = value;
+				OnPropertyChanged();
+			}
+		}
+
+		public Issue19786()
+		{
+			InitializeComponent();
+
+			AddItemCommand = new Command(() =>
+			{
+				Items.Add(Items.Count.ToString());
+			});
+
+			RemoveItemCommand = new Command(() =>
+			{
+				if (Items.Count > 0)
+					Items.RemoveAt(Items.Count - 1);
+			});
+
+			GoToNextItemCommand = new Command(() =>
+			{
+				if (Position < Items.Count - 1)
+					Position++;
+			});
+
+			BindingContext = this;
+		}
+	}
+}

src/Controls/src/Core/Handlers/Items/Android/MauiCarouselRecyclerView.cs

@@ -128,9 +128,9 @@ public override void UpdateAdapter()
 
 			var oldItemViewAdapter = ItemsViewAdapter;
 
+			UnsubscribeCollectionItemsSourceChanged(ItemsViewAdapter);
 			if (oldItemViewAdapter != null && _initialized)
 			{
-				UnsubscribeCollectionItemsSourceChanged(oldItemViewAdapter);
 				ItemsView.SetValueFromRenderer(CarouselView.PositionProperty, 0);
 				ItemsView.SetValueFromRenderer(CarouselView.CurrentItemProperty, null);
 			}

src/Controls/tests/UITests/Tests/Issues/Issue19786.cs

@@ -0,0 +1,31 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.AppiumTests.Issues
+{
+	public class Issue19786 : _IssuesUITest
+	{
+		public Issue19786(TestDevice device) : base(device)
+		{
+		}
+
+		public override string Issue => "[Android] Crash removing item from CarouselView";
+
+		[Test]
+		[Category(UITestCategories.CarouselView)]
+		public void RemovingItemsShouldNotCauseCrash()
+		{
+			_ = App.WaitForElement("addItemButton");
+			App.Click("addItemButton");
+			App.Click("addItemButton");
+			App.Click("addItemButton");
+			App.Click("goToNextItemButton");
+			App.Click("goToNextItemButton");
+			App.Click("removeLastItemButton");
+			App.Click("removeLastItemButton");
+			App.Click("removeLastItemButton");
+		}
+
+	}
+}