NullUnrestrictedUser __str__ broken

[Bug Importer]

AccessControl/User.py, NullUnrestrictedUser - the getUserName method returns a tuple of (None,None). Unfortunately, it derives from BasicUser, which defines __str__ to be getUserName. Thus, when trying to coerce the emergency user when an emergency user doesn't exist, as happens in BasicUserFolder's validate method ("if emergency and user is emergency"), a TypeError is raised, because __str__ doesn't return a string, it returns a tuple.

Either __str__ should be fixed, probably to return str() of getUserName, and/or NullUnrestrictedUser should be set to be false - add a def __len__(self): return 0

[Tres Seaver (tseaver)]

Fix committed to the 2.12 branch:

 http://svn.zope.org/Zope/branches/2.12/?rev=112356&view=rev

and the trunk:

 http://svn.zope.org/Zope/trunk/?rev=112357&view=rev