Hmm, I suppose that while the filename is latin1-encoded,
Py_FileSystemDefaultEncoding is "utf-8" and therefore os.listdir fails
decoding the filename and falls back on returning a byte string.
It was acceptable in Python 2.x but is a very annoying problem in py3k
now that unicode and bytes objects can't be mixed together anymore. I'm
bumping this to critical, although there is probably no clean solution.