From 08c451c6760d3d6e5808144f0497da292c38b608 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 27 Aug 2020 11:31:12 +0100
Subject: [PATCH 1/3] add a failing unit test.

---
 .../ContextMenuTests.cs                       | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
index 7a2109e5a7..c179aef9ac 100644
--- a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
@@ -1,5 +1,6 @@
 using System;
 using Avalonia.Input;
+using Avalonia.LogicalTree;
 using Avalonia.Markup.Xaml;
 using Avalonia.Markup.Xaml.MarkupExtensions;
 using Avalonia.Platform;
@@ -132,6 +133,44 @@ namespace Avalonia.Controls.UnitTests
                 popupImpl.Verify(x => x.Show(), Times.Exactly(2));
             }
         }
+        
+        [Fact]
+        public void Context_Menu_Can_Be_Shared_Between_Controls_Even_After_A_Control_Is_Removed_From_Visual_Tree()
+        {
+            using (Application())
+            {
+                var sut = new ContextMenu();
+                var target1 = new Panel
+                {
+                    ContextMenu = sut
+                };
+
+                var target2 = new Panel
+                {
+                    ContextMenu = sut
+                };
+
+                var sp = new StackPanel { Children = { target1, target2 } };
+                var window = new Window { Content = sp };
+                
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                _mouse.Click(target1, MouseButton.Right);
+
+                Assert.True(sut.IsOpen);
+
+                _mouse.Click(target2, MouseButton.Left);
+                
+                Assert.False(sut.IsOpen);
+                
+                sp.Children.Remove(target1);
+                
+                _mouse.Click(target2, MouseButton.Right);
+                
+                Assert.True(sut.IsOpen);
+            }
+        }
 
         [Fact]
         public void Cancelling_Opening_Does_Not_Show_ContextMenu()

From 505b54dd88d1a0d26bddc8ba0031002c00ac80b2 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 27 Aug 2020 11:34:07 +0100
Subject: [PATCH 2/3] update _popup.Placement target everytime the context menu
 is opened.

---
 src/Avalonia.Controls/ContextMenu.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/Avalonia.Controls/ContextMenu.cs b/src/Avalonia.Controls/ContextMenu.cs
index 9bb4cc4816..c4df5c1815 100644
--- a/src/Avalonia.Controls/ContextMenu.cs
+++ b/src/Avalonia.Controls/ContextMenu.cs
@@ -279,6 +279,11 @@ namespace Avalonia.Controls
                 ((ISetLogicalParent)_popup).SetParent(control);
             }
 
+            if (PlacementTarget is null && _popup.PlacementTarget != control)
+            {
+                _popup.PlacementTarget = control;
+            }
+
             _popup.Child = this;
             IsOpen = true;
             _popup.IsOpen = true;

From c98822c77324212d7de3b7d92d58c01efd45f485 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 27 Aug 2020 11:45:47 +0100
Subject: [PATCH 3/3] use uithread render timer on windows. to prevent opengl
 crashing.

---
 src/Windows/Avalonia.Win32/Win32Platform.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Windows/Avalonia.Win32/Win32Platform.cs b/src/Windows/Avalonia.Win32/Win32Platform.cs
index af6058d197..8840dcacef 100644
--- a/src/Windows/Avalonia.Win32/Win32Platform.cs
+++ b/src/Windows/Avalonia.Win32/Win32Platform.cs
@@ -88,7 +88,7 @@ namespace Avalonia.Win32
                 .Bind<IPlatformSettings>().ToConstant(s_instance)
                 .Bind<IPlatformThreadingInterface>().ToConstant(s_instance)
                 .Bind<IRenderLoop>().ToConstant(new RenderLoop())
-                .Bind<IRenderTimer>().ToConstant(new DefaultRenderTimer(60))
+                .Bind<IRenderTimer>().ToConstant(new UiThreadRenderTimer(60))
                 .Bind<ISystemDialogImpl>().ToSingleton<SystemDialogImpl>()
                 .Bind<IWindowingPlatform>().ToConstant(s_instance)
                 .Bind<PlatformHotkeyConfiguration>().ToSingleton<PlatformHotkeyConfiguration>()