nodeName does not check whether elem exists

[anonymous]

See ​http://stackoverflow.com/questions/283316/ie6-and-ie7-sometimes-have-a-jquery-bug-with-nodename-is-null-or-not-an-object for further info.

[dmethvin]

Since the linked post is from 2008 and there still is no test case three years later, I'll just close this as invalid. If someone has a test case that shows a problem calling documented jQuery APIs with valid arguments, please create a separate ticket.