From df164ee618b80e0a70bf23718a3731f185d2e844 Mon Sep 17 00:00:00 2001
From: Morten Christensen <unknown@kiln.example.com>
Date: Wed, 6 Mar 2013 08:02:09 -0100
Subject: [PATCH] Fixes U4-1835 by checking if the value is null before running
 the regex validation against the value.

---
 src/Umbraco.Core/Models/PropertyType.cs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Umbraco.Core/Models/PropertyType.cs b/src/Umbraco.Core/Models/PropertyType.cs
index c67a2bd2ed..f9155f1894 100644
--- a/src/Umbraco.Core/Models/PropertyType.cs
+++ b/src/Umbraco.Core/Models/PropertyType.cs
@@ -338,6 +338,9 @@ namespace Umbraco.Core.Models
             //Check against Regular Expression for Legacy DataTypes
             if(!string.IsNullOrEmpty(ValidationRegExp))
             {
+                if (value == null)
+                    return false;
+
                 var regexPattern = new Regex(ValidationRegExp);
                 return regexPattern.IsMatch(value.ToString());
             }