David,

Can you weigh in on this?

I am -1 on improving Internaldate2tuple(). I think the module should provide a function that would return an aware datetime object instead of a timetuple.

The proposed patch will make error reporting from Internaldate2tuple() inconsistent: invalid bytes result in None return while non-ASCII characters in strings would raise an encoding error.  While I don't like the "if not mo: return None" logic, if compatibility with 2.x is the goal, encoding errors should be caught and converted to return None.