contrib/casesmash.py

highlight: fix encoding issues to enable Py3 compatibility

This commit fixes various encoding issues with the `highlight` extension
to enable compatibility with Python 3. Python `.encode()` and `.decode()`
requires the target encoding to be passed as a `str`, so the value of
`mercurial.encoding.encoding` must be converted before passing to the
function. Pygments also assumes the `str` type for values it works with,
so we must perform conversions before and after receiving values from its
APIs.

After applying this patch, `test-highlight.t` passes under Python 3. We
add it to `python3-whitelist` as well.

Tested with Pygments 2.4.2.

Differential Revision: https://phab.mercurial-scm.org/D6832

from __future__ import absolute_import
import __builtin__
import os
from mercurial import (
    util,
)

def lowerwrap(scope, funcname):
    f = getattr(scope, funcname)
    def wrap(fname, *args, **kwargs):
        d, base = os.path.split(fname)
        try:
            files = os.listdir(d or '.')
        except OSError:
            files = []
        if base in files:
            return f(fname, *args, **kwargs)
        for fn in files:
            if fn.lower() == base.lower():
                return f(os.path.join(d, fn), *args, **kwargs)
        return f(fname, *args, **kwargs)
    scope.__dict__[funcname] = wrap

def normcase(path):
    return path.lower()

os.path.normcase = normcase

for f in 'file open'.split():
    lowerwrap(__builtin__, f)

for f in "chmod chown open lstat stat remove unlink".split():
    lowerwrap(os, f)

for f in "exists lexists".split():
    lowerwrap(os.path, f)

lowerwrap(util, 'posixfile')