From 44818c1b09cf323df7a5707a5313da4ddc011220 Mon Sep 17 00:00:00 2001
From: Steve Wagner <lanwin@lanwin.de>
Date: Wed, 12 May 2010 15:55:49 +0200
Subject: [PATCH] Use better way of detecting the Nullable underlying type.

---
 source/MongoDB/Configuration/Mapping/Model/MemberMapBase.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/MongoDB/Configuration/Mapping/Model/MemberMapBase.cs b/source/MongoDB/Configuration/Mapping/Model/MemberMapBase.cs
index 36a5aa23..b843f014 100644
--- a/source/MongoDB/Configuration/Mapping/Model/MemberMapBase.cs
+++ b/source/MongoDB/Configuration/Mapping/Model/MemberMapBase.cs
@@ -78,7 +78,7 @@ public virtual void SetValue(object instance, object value)
                         _memberReturnType.GetGenericTypeDefinition() == typeof(Nullable<>))
                     {
                         if(value!=null)
-                            value = Convert.ChangeType(value, _memberReturnType.GetGenericArguments().First());
+                            value = Convert.ChangeType(value, Nullable.GetUnderlyingType(valueType));
                     }
                     else if(code != TypeCode.Object)
                         value = Convert.ChangeType(value, _memberReturnType);