Added failing tests for MenuItem.TemplatedParent.

Seems #8412 caused `Menu.TemplatedParent` to get set to the parent `MenuItem` when re-opening a popup.

tests/Avalonia.Controls.UnitTests/MenuItemTests.cs

@@ -8,6 +8,7 @@ using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Platform;
 using Avalonia.UnitTests;
+using Avalonia.VisualTree;
 using Moq;
 using Xunit;
 
@@ -301,6 +302,49 @@ namespace Avalonia.Controls.UnitTests
                 Assert.Equal(3, canExecuteCallCount);
             }
         }
+
+
+        [Fact]
+        public void TemplatedParent_Should_Not_Be_Applied_To_Submenus()
+        {
+            using (Application())
+            {
+                MenuItem topLevelMenu;
+                MenuItem childMenu1;
+                MenuItem childMenu2;
+                var menu = new Menu
+                {
+                    Items = new[]
+                    {
+                        (topLevelMenu = new MenuItem
+                        {
+                            Header = "Foo",
+                            Items = new[]
+                            {
+                                (childMenu1 = new MenuItem { Header = "Bar" }),
+                                (childMenu2 = new MenuItem { Header = "Baz" }),
+                            }
+                        }),
+                    }
+                };
+
+                var window = new Window { Content = menu };
+                window.LayoutManager.ExecuteInitialLayoutPass();
+
+                topLevelMenu.IsSubMenuOpen = true;
+
+                Assert.True(((IVisual)childMenu1).IsAttachedToVisualTree);
+                Assert.Null(childMenu1.TemplatedParent);
+                Assert.Null(childMenu2.TemplatedParent);
+
+                topLevelMenu.IsSubMenuOpen = false;
+                topLevelMenu.IsSubMenuOpen = true;
+
+                Assert.Null(childMenu1.TemplatedParent);
+                Assert.Null(childMenu2.TemplatedParent);
+            }
+        }
+
         private IDisposable Application()
         {
             var screen = new PixelRect(new PixelPoint(), new PixelSize(100, 100));

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

@@ -295,7 +295,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         }
 
         [Fact]
-        public void Templated_Control_With_Popup_In_Template_Should_Set_TemplatedParent()
+        public void ContentControl_With_Popup_In_Template_Should_Set_TemplatedParent()
         {
             // Test uses OverlayPopupHost default template
             using (CreateServices())
@@ -384,6 +384,134 @@ namespace Avalonia.Controls.UnitTests.Primitives
             }
         }
 
+        [Fact]
+        public void ItemsControl_With_Popup_In_Template_Should_Set_TemplatedParent()
+        {
+            // Test uses OverlayPopupHost default template
+            using (CreateServices())
+            {
+                PopupItemsControl target;
+                var item = new Border();
+                var root = PreparedWindow(target = new PopupItemsControl
+                {
+                    Items = new[] { item },
+                    Template = new FuncControlTemplate<PopupItemsControl>(PopupItemsControlTemplate),
+                }); ;
+                root.Show();
+
+                target.ApplyTemplate();
+
+                var popup = (Popup)target.GetTemplateChildren().First(x => x.Name == "popup");
+                popup.Open();
+
+                var popupRoot = (Control)popup.Host;
+                popupRoot.Measure(Size.Infinity);
+                popupRoot.Arrange(new Rect(popupRoot.DesiredSize));
+
+                var children = popupRoot.GetVisualDescendants().ToList();
+                var types = children.Select(x => x.GetType().Name).ToList();
+
+                if (UsePopupHost)
+                {
+                    Assert.Equal(
+                        new[]
+                        {
+                            "LayoutTransformControl",
+                            "VisualLayerManager",
+                            "ContentPresenter",
+                            "ItemsPresenter",
+                            "StackPanel",
+                            "Border",
+                        },
+                        types);
+                }
+                else
+                {
+                    Assert.Equal(
+                        new[]
+                        {
+                            "LayoutTransformControl",
+                            "Panel",
+                            "Border",
+                            "VisualLayerManager",
+                            "ContentPresenter",
+                            "ItemsPresenter",
+                            "StackPanel",
+                            "Border",
+                        },
+                        types);
+                }
+
+                var templatedParents = children
+                    .OfType<IControl>()
+                    .Select(x => x.TemplatedParent).ToList();
+
+                if (UsePopupHost)
+                {
+                    Assert.Equal(
+                        new object[]
+                        {
+                            popupRoot,
+                            popupRoot,
+                            popupRoot,
+                            target,
+                            target,
+                            null,
+                        },
+                        templatedParents);
+                }
+                else
+                {
+                    Assert.Equal(
+                        new object[]
+                        {
+                            popupRoot,
+                            popupRoot,
+                            popupRoot,
+                            popupRoot,
+                            popupRoot,
+                            target,
+                            target,
+                            null,
+                        },
+                        templatedParents);
+                }
+            }
+        }
+
+        [Fact]
+        public void Should_Not_Overwrite_TemplatedParent_Of_Item_In_ItemsControl_With_Popup_On_Second_Open()
+        {
+            // Test uses OverlayPopupHost default template
+            using (CreateServices())
+            {
+                PopupItemsControl target;
+                var item = new Border();
+                var root = PreparedWindow(target = new PopupItemsControl
+                {
+                    Items = new[] { item },
+                    Template = new FuncControlTemplate<PopupItemsControl>(PopupItemsControlTemplate),
+                });
+                root.Show();
+
+                target.ApplyTemplate();
+
+                var popup = (Popup)target.GetTemplateChildren().First(x => x.Name == "popup");
+                popup.Open();
+
+                var popupRoot = (Control)popup.Host;
+                popupRoot.Measure(Size.Infinity);
+                popupRoot.Arrange(new Rect(popupRoot.DesiredSize));
+
+                Assert.Null(item.TemplatedParent);
+
+                popup.Close();
+                popup.Open();
+
+                Assert.Null(item.TemplatedParent);
+            }
+        }
+
         [Fact]
         public void DataContextBeginUpdate_Should_Not_Be_Called_For_Controls_That_Dont_Inherit()
         {
@@ -979,10 +1107,27 @@ namespace Avalonia.Controls.UnitTests.Primitives
             }.RegisterInNameScope(scope);
         }
 
+        private static IControl PopupItemsControlTemplate(PopupItemsControl control, INameScope scope)
+        {
+            return new Popup
+            {
+                Name = "popup",
+                PlacementTarget = control,
+                Child = new ItemsPresenter
+                {
+                    [~ItemsPresenter.ItemsProperty] = control[~ItemsControl.ItemsProperty],
+                }
+            }.RegisterInNameScope(scope);
+        }
+
         private class PopupContentControl : ContentControl
         {
         }
 
+        private class PopupItemsControl : ItemsControl
+        {
+        }
+
         private class TestControl : Decorator
         {
             public event EventHandler DataContextBeginUpdate;