From 00fbc5cea70b6925b1fa121f3868cc1d300f6b2d Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Tue, 6 Jun 2017 01:30:21 +0300
Subject: [PATCH] Use (0, 0) as default for non-existing PreviousMeasure

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

diff --git a/src/Avalonia.Layout/LayoutManager.cs b/src/Avalonia.Layout/LayoutManager.cs
index ebf6411beb..ed2b930114 100644
--- a/src/Avalonia.Layout/LayoutManager.cs
+++ b/src/Avalonia.Layout/LayoutManager.cs
@@ -133,7 +133,7 @@ namespace Avalonia.Layout
 
             if (!control.IsMeasureValid)
             {
-                control.Measure(control.PreviousMeasure.Value);
+                control.Measure(control.PreviousMeasure ?? default(Size));
             }
 
             _toMeasure.Remove(control);