From fb4601f65b0b51e58bd112d4c80e89965d44788e Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Tue, 21 Jul 2020 17:24:54 -0300
Subject: [PATCH] clean up when detaching caption buttons and templates change.

---
 src/Avalonia.Controls/Chrome/CaptionButtons.cs | 6 ++----
 src/Avalonia.Controls/Chrome/TitleBar.cs       | 5 +++++
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/Avalonia.Controls/Chrome/CaptionButtons.cs b/src/Avalonia.Controls/Chrome/CaptionButtons.cs
index 75d6c366b8..a86cbc271b 100644
--- a/src/Avalonia.Controls/Chrome/CaptionButtons.cs
+++ b/src/Avalonia.Controls/Chrome/CaptionButtons.cs
@@ -38,12 +38,10 @@ namespace Avalonia.Controls.Chrome
         {
             if (_disposables != null)
             {
-                var layer = ChromeOverlayLayer.GetOverlayLayer(_hostWindow);
-
-                layer?.Children.Remove(this);
-
                 _disposables.Dispose();
                 _disposables = null;
+
+                _hostWindow = null;
             }
         }
 
diff --git a/src/Avalonia.Controls/Chrome/TitleBar.cs b/src/Avalonia.Controls/Chrome/TitleBar.cs
index 3061e0a06b..c0c8076dd8 100644
--- a/src/Avalonia.Controls/Chrome/TitleBar.cs
+++ b/src/Avalonia.Controls/Chrome/TitleBar.cs
@@ -42,6 +42,8 @@ namespace Avalonia.Controls.Chrome
         {
             base.OnApplyTemplate(e);
 
+            _captionButtons?.Detach();
+            
             _captionButtons = e.NameScope.Get<CaptionButtons>("PART_CaptionButtons");
 
             if (VisualRoot is Window window)
@@ -87,6 +89,9 @@ namespace Avalonia.Controls.Chrome
             base.OnDetachedFromVisualTree(e);
 
             _disposables?.Dispose();
+            
+            _captionButtons?.Detach();
+            _captionButtons = null;
         }
     }
 }