The fix for issue4050 broke some of my doctests. Minimal test:

import doctest, inspect
def test():
    '''
    >>> def x(): pass
    >>> inspect.getsource(x)
    'def x(): pass\\n'
    '''
doctest.run_docstring_examples(test, globals())

This works in 2.6, but not in 2.7. Reason is that inspect.getsourcefile() finds the fake filename '<docTest NoName[0]>', which it doesn't understand. In 2.6, inspect.getmodule() is also tried, which first looks at obj.__module__, and the filename can be derived from that. I suggest that inspect.getsourcefile() grows some code to use this trick if the filename seems fake (f[0] + f[-1] == '<>').