[PATCH 5 of 5] Introduce a mechanism to handle MBCS file name correctly on Windows

[Matt Mackall]

On Sun, 2008-01-06 at 21:26 +0900, Shun-ichi Goto wrote:
> +        # codec and alias names of sjis and big5 to be faked.
> +        _problematic_encodings = frozenset([
> +                'big5', 'big5-tw', 'csbig5',
> +                'big5hkscs', 'big5-hkscs', 'hkscs',
> +                'cp932', '932', 'ms932', 'mskanji', 'ms-kanji',
> +                'shift_jis', 'csshiftjis', 'shiftjis', 'sjis', 's_jis',
> +                'shift_jis_2004', 'shiftjis2004', 'sjis_2004', 'sjis2004',
> +                'shift_jisx0213', 'shiftjisx0213', 'sjisx0213', 's_jisx0213',
> +                ])

Meh. I'm not a fan of sets. This would have been cleaner as
"""strings""".split()

> +        def _withdecoding(func):
> +            """Return wrapper function for func to oprerate MBCS string.
> +            The wrapper function trys decoding if need and do the job.
> +            Return value is encoded if deocded."""
> +
> +            def encode(s):
> +                if isinstance(s, unicode):
> +                    return s.encode(_encoding)
> +                else:
> +                    return s

I assume we only get unicode strings passed in because these things call
each other internally? Messing with the Python internals like this is a
little scary and it'll break things that import Mercurial modules.

> +            
> +            def wrapped(*args):
> +                # fake is only for relevant environment.
> +                if _encoding.lower() not in _problematic_encodings:
> +                    return func(*args)

This is the wrong place to do this. If you move it up a layer, you can
do "return func" and skip a level of indirection. This is all probably
overly complex as well.

-- 
Mathematics is the supreme nostalgia of our time.