From 70d75c0eb5db776fa59fffaaf69c1b9c8ba6d9f1 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Mon, 12 Feb 2018 23:55:36 +0100
Subject: [PATCH 1/2] Fix Window auto-sizing.

`Window` was acting like `SizeToContent="WidthAndHeight"` was set even when it wasn't. This fixes that.
---
 src/Avalonia.Controls/Window.cs | 38 ++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/src/Avalonia.Controls/Window.cs b/src/Avalonia.Controls/Window.cs
index 7fed712e07..f3ad4dbbd9 100644
--- a/src/Avalonia.Controls/Window.cs
+++ b/src/Avalonia.Controls/Window.cs
@@ -374,27 +374,31 @@ namespace Avalonia.Controls
         {
             var sizeToContent = SizeToContent;
             var clientSize = ClientSize;
-            Size constraint;
+            Size constraint = clientSize;
 
-            switch (sizeToContent)
+            if ((sizeToContent & SizeToContent.Width) != 0)
             {
-                case SizeToContent.Width:
-                    constraint = new Size(double.PositiveInfinity, ClientSize.Height);
-                    break;
-                case SizeToContent.Height:
-                    constraint = new Size(ClientSize.Width, double.PositiveInfinity);
-                    break;
-                case SizeToContent.WidthAndHeight:
-                    constraint = Size.Infinity;
-                    break;
-                case SizeToContent.Manual:
-                    constraint = ClientSize;
-                    break;
-                default:
-                    throw new InvalidOperationException("Invalid value for SizeToContent.");
+                constraint = constraint.WithWidth(double.PositiveInfinity);
             }
 
-            return base.MeasureOverride(constraint);
+            if ((sizeToContent & SizeToContent.Height) != 0)
+            {
+                constraint = constraint.WithHeight(double.PositiveInfinity);
+            }
+
+            var result = base.MeasureOverride(constraint);
+
+            if ((sizeToContent & SizeToContent.Width) == 0)
+            {
+                result = result.WithWidth(clientSize.Width);
+            }
+
+            if ((sizeToContent & SizeToContent.Height) == 0)
+            {
+                result = result.WithHeight(clientSize.Height);
+            }
+
+            return result;
         }
 
         protected override void HandleClosed()

From 2af1f20108a1d3ce1c854e30899f7a67327cbe89 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Tue, 13 Feb 2018 00:12:12 +0100
Subject: [PATCH 2/2] Mark SizeToContent with [Flags].

And explicitly assign values.
---
 src/Avalonia.Controls/Window.cs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/Avalonia.Controls/Window.cs b/src/Avalonia.Controls/Window.cs
index f3ad4dbbd9..893859b915 100644
--- a/src/Avalonia.Controls/Window.cs
+++ b/src/Avalonia.Controls/Window.cs
@@ -19,27 +19,28 @@ namespace Avalonia.Controls
     /// <summary>
     /// Determines how a <see cref="Window"/> will size itself to fit its content.
     /// </summary>
+    [Flags]
     public enum SizeToContent
     {
         /// <summary>
         /// The window will not automatically size itself to fit its content.
         /// </summary>
-        Manual,
+        Manual = 0,
 
         /// <summary>
         /// The window will size itself horizontally to fit its content.
         /// </summary>
-        Width,
+        Width = 1,
 
         /// <summary>
         /// The window will size itself vertically to fit its content.
         /// </summary>
-        Height,
+        Height = 2,
 
         /// <summary>
         /// The window will size itself horizontally and vertically to fit its content.
         /// </summary>
-        WidthAndHeight,
+        WidthAndHeight = 3,
     }
 
     /// <summary>