From c607b1a4dce62c2fdcb4b26c7656aab444c76d27 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Mon, 24 Aug 2020 12:00:53 +0100
Subject: [PATCH 1/4] prevent popup crashing when mainwindow has closed and
 popup still open.

---
 src/Avalonia.Native/WindowImplBase.cs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/Avalonia.Native/WindowImplBase.cs b/src/Avalonia.Native/WindowImplBase.cs
index 08c5d51ea0..da008c1e7a 100644
--- a/src/Avalonia.Native/WindowImplBase.cs
+++ b/src/Avalonia.Native/WindowImplBase.cs
@@ -94,8 +94,13 @@ namespace Avalonia.Native
         {
             get
             {
-                var s = _native.GetClientSize();
-                return new Size(s.Width, s.Height);
+                if (_native != null)
+                {
+                    var s = _native.GetClientSize();
+                    return new Size(s.Width, s.Height);
+                }
+
+                return default;
             }
         }
 

From 838daf76835c570565d3079a39284f34539f5265 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Mon, 24 Aug 2020 17:18:37 +0100
Subject: [PATCH 2/4] dont make native handle null so closing events can
 complete.

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

diff --git a/src/Avalonia.Native/WindowImplBase.cs b/src/Avalonia.Native/WindowImplBase.cs
index da008c1e7a..56cf544d9d 100644
--- a/src/Avalonia.Native/WindowImplBase.cs
+++ b/src/Avalonia.Native/WindowImplBase.cs
@@ -149,7 +149,6 @@ namespace Avalonia.Native
             void IAvnWindowBaseEvents.Closed()
             {
                 var n = _parent._native;
-                _parent._native = null;
                 try
                 {
                     _parent?.Closed?.Invoke();
@@ -158,6 +157,7 @@ namespace Avalonia.Native
                 {
                     n?.Dispose();
                 }
+                
                 _parent._mouse.Dispose();
             }
 

From 84f8f75cc5f7647332001f7b9f324496fc04baa7 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Tue, 25 Aug 2020 11:59:36 +0100
Subject: [PATCH 3/4] prevent screens api crashing if it has been disposed.

---
 src/Avalonia.Native/ScreenImpl.cs | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/src/Avalonia.Native/ScreenImpl.cs b/src/Avalonia.Native/ScreenImpl.cs
index 0d593bc2f6..c6d751c7ad 100644
--- a/src/Avalonia.Native/ScreenImpl.cs
+++ b/src/Avalonia.Native/ScreenImpl.cs
@@ -20,21 +20,26 @@ namespace Avalonia.Native
         {
             get
             {
-                var count = ScreenCount;
-                var result = new Screen[count];
-
-                for(int i = 0; i < count; i++)
+                if (_native != null)
                 {
-                    var screen = _native.GetScreen(i);
+                    var count = ScreenCount;
+                    var result = new Screen[count];
+
+                    for (int i = 0; i < count; i++)
+                    {
+                        var screen = _native.GetScreen(i);
+
+                        result[i] = new Screen(
+                            screen.PixelDensity,
+                            screen.Bounds.ToAvaloniaPixelRect(),
+                            screen.WorkingArea.ToAvaloniaPixelRect(),
+                            screen.Primary);
+                    }
 
-                    result[i] = new Screen(
-                        screen.PixelDensity,
-                        screen.Bounds.ToAvaloniaPixelRect(),
-                        screen.WorkingArea.ToAvaloniaPixelRect(),
-                        screen.Primary);
+                    return result;
                 }
 
-                return result;
+                return new List<Screen>();
             }
         }
 

From 0f87897aaee9b156839ae414f3bce269d6f0092e Mon Sep 17 00:00:00 2001
From: danwalmsley <dan@walms.co.uk>
Date: Tue, 25 Aug 2020 14:44:16 +0100
Subject: [PATCH 4/4] Use Array.Empty instead of list.

Co-authored-by: jp2masa <jp2masa@users.noreply.github.com>
---
 src/Avalonia.Native/ScreenImpl.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Native/ScreenImpl.cs b/src/Avalonia.Native/ScreenImpl.cs
index c6d751c7ad..f28be52dd5 100644
--- a/src/Avalonia.Native/ScreenImpl.cs
+++ b/src/Avalonia.Native/ScreenImpl.cs
@@ -39,7 +39,7 @@ namespace Avalonia.Native
                     return result;
                 }
 
-                return new List<Screen>();
+                return Array.Empty<Screen>();
             }
         }