From a01fb157e400befa2e477549867d22a0cabec3e3 Mon Sep 17 00:00:00 2001
From: Andrey Kunchev <donandren@gmail.com>
Date: Mon, 21 Dec 2020 12:53:31 +0200
Subject: [PATCH 1/2] add some tests for contextmenu open without params

---
 .../ContextMenuTests.cs                       | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
index 39a3250686..f3a1316c7d 100644
--- a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
@@ -44,6 +44,55 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
+        [Fact]
+        public void Open_Should_Use_Default_Control()
+        {
+            using (Application())
+            {
+                var sut = new ContextMenu();
+                var target = new Panel
+                {
+                    ContextMenu = sut
+                };
+
+                var window = new Window { Content = target };
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                bool opened = false;
+
+                sut.MenuOpened += (sender, args) =>
+                {
+                    opened = true;
+                };
+
+                sut.Open();
+
+                Assert.True(opened);
+            }
+        }
+
+        [Fact]
+        public void Open_Should_Raise_Exception_If_AlreadyDetached()
+        {
+            using (Application())
+            {
+                var sut = new ContextMenu();
+                var target = new Panel
+                {
+                    ContextMenu = sut
+                };
+
+                var window = new Window { Content = target };
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                target.ContextMenu = null;
+
+               Assert.ThrowsAny<Exception>(()=> sut.Open());
+            }
+        }
+
         [Fact]
         public void Closing_Raises_Single_Closed_Event()
         {

From a045e963ac2a6def331ace62b977b52bc89636b6 Mon Sep 17 00:00:00 2001
From: Andrey Kunchev <donandren@gmail.com>
Date: Mon, 21 Dec 2020 12:54:23 +0200
Subject: [PATCH 2/2] ContextMenu.Open should call Open(null) so it doesn't
 break working scenarios

---
 src/Avalonia.Controls/ContextMenu.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/ContextMenu.cs b/src/Avalonia.Controls/ContextMenu.cs
index 5e17182f3e..fb8080f0d4 100644
--- a/src/Avalonia.Controls/ContextMenu.cs
+++ b/src/Avalonia.Controls/ContextMenu.cs
@@ -246,7 +246,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Opens the menu.
         /// </summary>
-        public override void Open() => throw new NotSupportedException();
+        public override void Open() => Open(null);
 
         /// <summary>
         /// Opens a context menu on the specified control.