Extract of send_head():

        path = self.translate_path(self.path)
        f = None
        if os.path.isdir(path):
            parts = urllib.parse.urlsplit(self.path)
            ...

urllib.parse.urlsplit('//www.python.org/%2f..') returns:

SplitResult(scheme='', netloc='www.python.org', path='/%2f..', query='', fragment='')

Is urlsplit() the correct function to call here? www.python.org is part of the path, not of the netloc.