Either way -- this needs to be reverted or fixed. It's a nasty gotcha for folks writing Python web services at the moment. I'm still for reverting, per my reasons above.

Dave Chambers, I'm not for "faster but broken" but for "faster and fixed" -- from what I've shown above, it's the Windows registry that's broken, so removing read_windows_registry() entirely would fix this (and as a bonus, be faster and simplify the code :-).

Per your suggestion http://bugs.python.org/issue15207#msg177092 -- I don't understand how mimetypes.py would know the types "that aren't hardcoded".

R. David Murray, I don't understand the advantage of trying to maintain a list of "Windows fixes". What if this list was wrong, or there was a Windows update which broke more mime types? Why can't we just avoid the complication and go back to the hardcoded types for Windows?