properly handle unicode characters in home dirs

[vit-tucek]

Jupyter fails to start when the user has Unicode characters in his homedir. This fixes that. See sagemath/sage-windows#10 (comment) and jupyter/jupyter_core#131

[minrk]

I believe we have a py3compat.str_to_unicode(s, encoding=sys.getfilesystemencoding())

Related question, though: does os.path.expanduser(u'~') do the right thing here, deferring to Python's on path-encoding logic?

[vit-tucek]

Python's path-encoding logic is broken. At least within Sage-on-Windows cygwin environment.

  File "/opt/sagemath-8.2/local/lib/python2.7/site-packages/notebook/notebookapp.py", line 214, in init_settings
    home = os.path.expanduser(u'~')
  File "/opt/sagemath-8.2/local/lib/python2.7/posixpath.py", line 293, in expanduser
    return (userhome + path[i:]) or '/'
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 7: ordinal not in range(128)

Changing the line

home = os.path.expanduser('~')

to

home = py3compat.str_to_unicode(os.path.expanduser('~'), encoding=sys.getfilesystemencoding())

works. Do you want me to this change?

[minrk]

Do you want me to this change?

Yes, that sounds great!

[vit-tucek]

Done.