(Note: I'm splitting this from #1342 because the fix is much simpler in
the non-Windows case)

py3k does not accept running from a path with non-ascii characters.

$ pwd
/home/antoine/py3k/héhé
$ ./python
Fatal Python error: Py_Initialize: can't initialize sys standard streams
Traceback (most recent call last):
  File "/home/antoine/py3k/pristine/Lib/encodings/__init__.py", line 32,
in <module>
TypeError: zipimporter() argument 1 must be string without null bytes,
not str
Abandon

The following patch solves the problem by fixing a bug in getargs.c
where the "no null bytes" check for non-ASCII strings was wrong.

There is still a failing test, test_xmlrpc, apparently because xmlrpc
wants to output its path in an HTTP header using the "ascii" encoding...
I'd say this is an xmlrpc issue and not an issue with the patch.