Fix NullReferenceException when inserting space after 'in' modifier

ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngine.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // CSharpCompletionEngine.cs
 //  
 // Author:
@@ -1806,6 +1806,8 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 					var inList = new CompletionDataWrapper(this);
 					
 					var expr = GetExpressionAtCursor();
+					if (expr == null)
+						return null;
 					var rr = ResolveExpression(expr);
 					
 					AddContextCompletion(

ICSharpCode.NRefactory.Tests/CSharp/CodeCompletion/CodeCompletionBugTests.cs

@@ -6009,7 +6009,17 @@ public class Testing
 			});
 		}
 
-
+		/// <summary>
+		/// NullReferenceException when inserting space after 'in' modifier
+		/// </summary>
+		[Test]
+		public void TestCrashContravariantTypeParameter ()
+		{
+			CompletionDataList provider = CreateProvider (
+				@"public delegate void ModelCollectionChangedEventHandler<in$ $T>();
+");
+			Assert.AreEqual(0, provider.Count);
+		}
 
 
 	}