view mercurial/i18n.py @ 24624:6f0e6fa9fdd7

dirs._addpath: don't mutate Python strings after exposing them (issue4589)

One of the rules of Python strings is that they're immutable. dirs._addpath
breaks this assumption for performance, which is fine as long as it is done
safely -- once a string is no longer internal-only it shouldn't be mutated.
Unfortunately, we weren't being safe here -- we were mutating 'key' even after
adding it to a dictionary.

This only really affects other C code that reads strings, so it's somewhat hard
to write a test for this without poking into the internal representation of the
string via ctypes or similar. There is currently no C code that reads the
output of the string, but there will likely be some soon as the bug indicates.

There's no significant difference in performance.

# i18n.py - internationalization support for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import encoding
import gettext as gettextmod, sys, os, locale

# modelled after templater.templatepath:
if getattr(sys, 'frozen', None) is not None:
    module = sys.executable
else:
    module = __file__


_languages = None
if (os.name == 'nt'
    and 'LANGUAGE' not in os.environ
    and 'LC_ALL' not in os.environ
    and 'LC_MESSAGES' not in os.environ
    and 'LANG' not in os.environ):
    # Try to detect UI language by "User Interface Language Management" API
    # if no locale variables are set. Note that locale.getdefaultlocale()
    # uses GetLocaleInfo(), which may be different from UI language.
    # (See http://msdn.microsoft.com/en-us/library/dd374098(v=VS.85).aspx )
    try:
        import ctypes
        langid = ctypes.windll.kernel32.GetUserDefaultUILanguage()
        _languages = [locale.windows_locale[langid]]
    except (ImportError, AttributeError, KeyError):
        # ctypes not found or unknown langid
        pass

_ugettext = None

def setdatapath(datapath):
    localedir = os.path.join(datapath, 'locale')
    t = gettextmod.translation('hg', localedir, _languages, fallback=True)
    global _ugettext
    _ugettext = t.ugettext

_msgcache = {}

def gettext(message):
    """Translate message.

    The message is looked up in the catalog to get a Unicode string,
    which is encoded in the local encoding before being returned.

    Important: message is restricted to characters in the encoding
    given by sys.getdefaultencoding() which is most likely 'ascii'.
    """
    # If message is None, t.ugettext will return u'None' as the
    # translation whereas our callers expect us to return None.
    if message is None or not _ugettext:
        return message

    if message not in _msgcache:
        if type(message) is unicode:
            # goofy unicode docstrings in test
            paragraphs = message.split(u'\n\n')
        else:
            paragraphs = [p.decode("ascii") for p in message.split('\n\n')]
        # Be careful not to translate the empty string -- it holds the
        # meta data of the .po file.
        u = u'\n\n'.join([p and _ugettext(p) or '' for p in paragraphs])
        try:
            # encoding.tolocal cannot be used since it will first try to
            # decode the Unicode string. Calling u.decode(enc) really
            # means u.encode(sys.getdefaultencoding()).decode(enc). Since
            # the Python encoding defaults to 'ascii', this fails if the
            # translated string use non-ASCII characters.
            _msgcache[message] = u.encode(encoding.encoding, "replace")
        except LookupError:
            # An unknown encoding results in a LookupError.
            _msgcache[message] = message
    return _msgcache[message]

def _plain():
    if 'HGPLAIN' not in os.environ and 'HGPLAINEXCEPT' not in os.environ:
        return False
    exceptions = os.environ.get('HGPLAINEXCEPT', '').strip().split(',')
    return 'i18n' not in exceptions

if _plain():
    _ = lambda message: message
else:
    _ = gettext