From 42f5055b47deea1d85d9d547a92db427165b07be Mon Sep 17 00:00:00 2001
From: Daniel Grunwald <daniel@danielgrunwald.de>
Date: Fri, 14 Sep 2012 23:35:58 +0200
Subject: [PATCH] Fix potential NullReferenceException in
 GetAccessibleMembers() if GetDefinition() returns null

---
 ICSharpCode.NRefactory.CSharp/Resolver/MemberLookup.cs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/ICSharpCode.NRefactory.CSharp/Resolver/MemberLookup.cs b/ICSharpCode.NRefactory.CSharp/Resolver/MemberLookup.cs
index c490f9b72b..ead362d155 100644
--- a/ICSharpCode.NRefactory.CSharp/Resolver/MemberLookup.cs
+++ b/ICSharpCode.NRefactory.CSharp/Resolver/MemberLookup.cs
@@ -167,8 +167,11 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				
 				List<IEntity> entities = new List<IEntity>();
 				entities.AddRange(type.GetMembers(options: GetMemberOptions.IgnoreInheritedMembers));
-				if (!targetIsTypeParameter)
-					entities.AddRange(type.GetNestedTypes(options: GetMemberOptions.IgnoreInheritedMembers | GetMemberOptions.ReturnMemberDefinitions).Select(t => t.GetDefinition()));
+				if (!targetIsTypeParameter) {
+					var nestedTypes = type.GetNestedTypes(options: GetMemberOptions.IgnoreInheritedMembers | GetMemberOptions.ReturnMemberDefinitions);
+					// GetDefinition() might return null if some IType has a strange implementation of GetNestedTypes.
+					entities.AddRange(nestedTypes.Select(t => t.GetDefinition()).Where(td => td != null));
+				}
 				
 				foreach (var entityGroup in entities.GroupBy(e => e.Name)) {