hgweb.cgi

pycompat: use os.fsencode() to re-encode sys.argv

Historically, the previous code made sense, as Py_EncodeLocale() and
fs.fsencode() could possibly use different encodings. However, this is not the
case anymore for Python 3.2, which uses the locale encoding as the filesystem
encoding (this is not true for later Python versions, but see below). See
https://vstinner.github.io/painful-history-python-filesystem-encoding.html for
a source and more background information.

Using os.fsencode() is safer, as the documentation for sys.argv says that it can
be used to get the original bytes. When doing further changes, the Python
developers will take care that this continues to work.

One concrete case where os.fsencode() is more correct is when enabling Python's
UTF-8 mode. Py_DecodeLocale() will use UTF-8 in this case. Our previous code
would have encoded it using the locale encoding (which might be different),
whereas os.fsencode() will encode it with UTF-8.

Since we don’t claim to support the UTF-8 mode, this is not really a bug and the
patch can go to the default branch. It might be a good idea to not commit this
to the stable branch, as it could in theory introduce regressions.

#!/usr/bin/env python
#
# An example hgweb CGI script, edit as necessary
# See also https://mercurial-scm.org/wiki/PublishingRepositories

# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = "/path/to/repo/or/config"

# Uncomment and adjust if Mercurial is not installed system-wide
# (consult "installed modules" path from 'hg debuginstall'):
# import sys; sys.path.insert(0, "/path/to/python/lib")

# Uncomment to send python tracebacks to the browser if an error occurs:
# import cgitb; cgitb.enable()

from mercurial import demandimport

demandimport.enable()
from mercurial.hgweb import hgweb, wsgicgi

application = hgweb(config)
wsgicgi.launch(application)