Fixed interface return type test.

ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngine.cs

@@ -1302,6 +1302,13 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 					if (resolved != null)
 						hintType = resolved.Item1.Type;
 				}
+
+				if (newParentNode is ReturnStatement) {
+					var varDecl = (ReturnStatement)newParentNode;
+					if (ctx.CurrentMember != null)
+						hintType = ctx.CurrentMember.ReturnType;
+				}
+
 				return CreateTypeCompletionData (hintType, hintTypeAst);
 //					IType callingType = NRefactoryResolver.GetTypeAtCursor (Document.CompilationUnit, Document.FileName, new TextLocation (document.Caret.Line, document.Caret.Column));
 //					ExpressionContext newExactContext = new NewCSharpExpressionFinder (dom).FindExactContextForNewCompletion (document, Document.CompilationUnit, Document.FileName, callingType);
@@ -1409,15 +1416,18 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 						// check if type is in inheritance tree.
 						if (hintType.GetDefinition () != null && !t.GetDefinition ().IsDerivedFrom (hintType.GetDefinition ()))
 							return false;
-						
+						if (t.Kind == TypeKind.Interface && hintType.Kind != TypeKind.Array)
+							return false;
 						// check for valid constructors
 						if (t.GetConstructors ().Count () == 0)
 							return true;
 						bool isProtectedAllowed = currentType != null ? currentType.Resolve (ctx).GetDefinition ().IsDerivedFrom (t.GetDefinition ()) : false;
 						return t.GetConstructors ().Any (m => lookup.IsAccessible (m, isProtectedAllowed));
 					};
+					if (!(hintType.Kind == TypeKind.Interface && hintType.Kind != TypeKind.Array)) {
 						DefaultCompletionString = GetShortType (hintType, GetState ());
 						wrapper.AddType (hintType, DefaultCompletionString);
+					}
 				} else {
 					DefaultCompletionString = hintTypeAst.ToString ();
 					wrapper.AddType (hintType, DefaultCompletionString);