Added failing test for removing selected item with BeginInit.

tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs

@@ -531,6 +531,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             };
 
             target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
             target.SelectedIndex = 1;
 
             Assert.Equal(items[1], target.SelectedItem);
@@ -549,6 +550,45 @@ namespace Avalonia.Controls.UnitTests.Primitives
             Assert.NotNull(receivedArgs);
             Assert.Empty(receivedArgs.AddedItems);
             Assert.Equal(new[] { removed }, receivedArgs.RemovedItems);
+            Assert.False(items.Single().IsSelected);
+        }
+
+        [Fact]
+        public void Removing_Selected_Item_Should_Clear_Selection_With_BeginInit()
+        {
+            var items = new AvaloniaList<Item>
+            {
+                new Item(),
+                new Item(),
+            };
+
+            var target = new SelectingItemsControl();
+            target.BeginInit();
+            target.Items = items;
+            target.Template = Template();
+            target.EndInit();
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+            target.SelectedIndex = 0;
+
+            Assert.Equal(items[0], target.SelectedItem);
+            Assert.Equal(0, target.SelectedIndex);
+
+            SelectionChangedEventArgs receivedArgs = null;
+
+            target.SelectionChanged += (_, args) => receivedArgs = args;
+
+            var removed = items[0];
+
+            items.RemoveAt(0);
+
+            Assert.Null(target.SelectedItem);
+            Assert.Equal(-1, target.SelectedIndex);
+            Assert.NotNull(receivedArgs);
+            Assert.Empty(receivedArgs.AddedItems);
+            Assert.Equal(new[] { removed }, receivedArgs.RemovedItems);
+            Assert.False(items.Single().IsSelected);
         }
 
         [Fact]