From c1a14a4507e3efbeba73a8b7e02082c05ac13f00 Mon Sep 17 00:00:00 2001
From: hpsa <ilm@hp.com>
Date: Tue, 24 Jan 2012 13:58:59 +0200
Subject: [PATCH] Fix exception when changing AvalonDock panes size during
 auto-layout change

---
 src/Libraries/AvalonDock/AvalonDock/ResizingPanel.cs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/Libraries/AvalonDock/AvalonDock/ResizingPanel.cs b/src/Libraries/AvalonDock/AvalonDock/ResizingPanel.cs
index 221258c9ce..dbaeef9ce1 100644
--- a/src/Libraries/AvalonDock/AvalonDock/ResizingPanel.cs
+++ b/src/Libraries/AvalonDock/AvalonDock/ResizingPanel.cs
@@ -882,6 +882,10 @@ namespace AvalonDock
             //Point draggedPoint = this.PointToScreenDPI(
             //    new Point(e.HorizontalChange, e.VerticalChange));
             Window wnd = Window.GetWindow(this);
+            if (wnd == null)
+            {
+                return;
+            }
             var trToWnd = TransformToAncestor(wnd);
             Vector transformedDelta = trToWnd.Transform(new Point(e.HorizontalChange, e.VerticalChange)) -
                 trToWnd.Transform(new Point());
@@ -1172,6 +1176,11 @@ namespace AvalonDock
 
             Size[] currentSizes = new Size[visibleChildren.Count];
             Window wnd = Window.GetWindow(this);
+            if (wnd == null)
+            {
+                InvalidateMeasure();
+                return;
+            }
             var trToWnd = TransformToAncestor(wnd).Inverse;
             Vector transformedDelta = trToWnd.Transform(new Point(e.HorizontalChange, e.VerticalChange)) -
                 trToWnd.Transform(new Point());