http://java.net/jira/browse/MACOSX_PORT-257 submitted 2011/08/10 by Yuri Nesterenko
Run an attached small example. It starts an application and adds a Menu with two MenuItems. Initially they have no shortcuts. Press the Button. Action will successfully setShortcut() to both items. Press the button again: now it should remove shortcuts using different ways for both items, calling setShortcut(null) and calling deleteShortcut(). Neither has any effect in macosx port.
We should accept empty KeyEquivalent in case of shortcut removing.