From f63d5dad9358418839a14b93a8f7799932ce9f5a Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Sun, 23 Jul 2017 21:29:43 +0300
Subject: [PATCH] Fixed bug with null values from markup extensions

---
 .../PortableXaml/AvaloniaXamlObjectWriter.cs                  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlObjectWriter.cs b/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlObjectWriter.cs
index f10de1a32f..860dbfec39 100644
--- a/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlObjectWriter.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlObjectWriter.cs
@@ -88,8 +88,8 @@ namespace Avalonia.Markup.Xaml.PortableXaml
             //Portable.Xaml.ComponentModel.ISupportInitialize
             //and we have Avalonia.ISupportInitialize so we need some hacks
             HandleBeginInit(value);
-
-            _delayedValuesHelper.BeginInit(value);
+            if (value != null)
+                _delayedValuesHelper.BeginInit(value);
 
             base.OnBeforeProperties(value);
         }