From d43108d442e09b61c53b173d2537428f503da8ee Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Wed, 20 May 2020 16:55:32 -0300
Subject: [PATCH] only report extended if we were able to.

---
 src/Windows/Avalonia.Win32/WindowImpl.cs | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/Windows/Avalonia.Win32/WindowImpl.cs b/src/Windows/Avalonia.Win32/WindowImpl.cs
index 6cacd0b6cc..af1e8e06ce 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.cs
@@ -692,14 +692,12 @@ namespace Avalonia.Win32
 
                 var hr = DwmExtendFrameIntoClientArea(_hwnd, ref margins);
 
-                //if (hr < 0)
+                if (hr == 0)
                 {
-                    // Handle the error.
+                    _isClientAreaExtended = true;
+                    _extendedMargins = new Thickness(margins.cxLeftWidth / Scaling, margins.cyTopHeight / Scaling, margins.cxRightWidth / Scaling, margins.cyBottomHeight / Scaling);
+                    ExtendClientAreaToDecorationsChanged?.Invoke(true);
                 }
-
-                _isClientAreaExtended = true;
-                _extendedMargins = new Thickness(margins.cxLeftWidth / Scaling, margins.cyTopHeight / Scaling, margins.cxRightWidth / Scaling, margins.cyBottomHeight / Scaling);
-                ExtendClientAreaToDecorationsChanged?.Invoke(true);
             }
         }