dotnet/corefx — pull request #68 by jltrem (2014-11-13 15:26:24+00:00)
Title: check for null parameter as base class does, but throw ArgumentException

The XmlAttributeCollection.SetNamedItem(XmlNode) override does parameter validation but does not check for null. Parent class does a null check to avoid a null ref exception. Added a null check to the override but throw an ArgumentException as is done for its other parameter checking. Also added this condition check to the existing NamedItemDoesNotExist test.