Fixed ambience NullReferenceException (bug introduced in revision 4954)

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/3.0@4993 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/CSharp/CSharpAmbience.cs

@@ -534,6 +534,8 @@ namespace ICSharpCode.SharpDevelop.Dom.CSharp
 		
 		static IReturnType GetElementType(IReturnType potentialArrayType)
 		{
+			if (potentialArrayType == null)
+				return null;
 			ArrayReturnType result;
 			while ((result = potentialArrayType.CastToArrayReturnType()) != null) {
 				potentialArrayType = result.ArrayElementType;

src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/VBNet/VBNetAmbience.cs

@@ -552,6 +552,8 @@ namespace ICSharpCode.SharpDevelop.Dom.VBNet
 		
 		static IReturnType GetElementType(IReturnType potentialArrayType)
 		{
+			if (potentialArrayType == null)
+				return null;
 			ArrayReturnType result;
 			while ((result = potentialArrayType.CastToArrayReturnType()) != null) {
 				potentialArrayType = result.ArrayElementType;