Replace deprecated locale.getdefaultlocale()

gettext.translation() can do most of the work for us, calling
gettext.find() and with fallback=True returning a NullTranslations if no
catalog is found.

The do_unicode parameter of install_builtin() should have been removed
in:
384e1e196 ("Remove Python 2 gettext builtin installation", 2020-04-15)

linkcheck/__init__.py

@@ -93,7 +93,7 @@ def get_link_pat(arg, strict=False):
     }
 
 
-def init_i18n(loc=None):
+def init_i18n():
     """Initialize i18n with the configured locale dir. The environment
     variable LOCPATH can also specify a locale dir.
 
@@ -104,7 +104,7 @@ def init_i18n(loc=None):
     else:
         # Need Python 3.9 for importlib.resources.files
         locdir = os.path.join(__path__[0], 'data', 'locale')
-    i18n.init(COMMAND_NAME, locdir, loc=loc)
+    i18n.init(COMMAND_NAME, locdir)
     # install translated log level names
     import logging
 

linkcheck/director/console.py

@@ -113,7 +113,6 @@ def print_locale_info(out=stderr):
     """Print locale info."""
     for key in ("LANGUAGE", "LC_ALL", "LC_CTYPE", "LANG"):
         print_env_info(key, out=out)
-    print(_("Default locale:"), i18n.get_locale(), file=out)
 
 
 # Environment variables influencing the interpreter execution

linkcheck/i18n.py

@@ -18,144 +18,26 @@ Application internationalization support.
 """
 
 # i18n support
-import os
 import locale
 import gettext
 import sys
 import codecs
 
-# more supported languages are added in init()
-supported_languages = {'en'}
-default_language = default_encoding = None
-default_directory = None
-default_domain = None
+default_encoding = None
 
 
-def install_builtin(translator, do_unicode):
-    """Install _() and _n() gettext methods into default namespace."""
+def init(domain, directory):
+    """Initialize this gettext i18n module and install the gettext translator class."""
+    global default_encoding
+    default_encoding = locale.getpreferredencoding(False)
+
+    translator = gettext.translation(domain, localedir=directory, fallback=True)
+
     import builtins
-
     builtins.__dict__['_'] = translator.gettext
-    # also install ngettext
     builtins.__dict__['_n'] = translator.ngettext
 
 
-class Translator(gettext.GNUTranslations):
-    """A translation class always installing its gettext methods into the
-    default namespace."""
-
-    def install(self, do_unicode):
-        """Install gettext methods into the default namespace."""
-        install_builtin(self, do_unicode)
-
-
-class NullTranslator(gettext.NullTranslations):
-    """A dummy translation class always installing its gettext methods into
-    the default namespace."""
-
-    def install(self, do_unicode):
-        """Install gettext methods into the default namespace."""
-        install_builtin(self, do_unicode)
-
-
-def init(domain, directory, loc=None):
-    """Initialize this gettext i18n module. Searches for supported languages
-    and installs the gettext translator class."""
-    global default_language, default_encoding, default_domain, default_directory
-    default_directory = directory
-    default_domain = domain
-    if os.path.isdir(directory):
-        # get supported languages
-        for lang in os.listdir(directory):
-            path = os.path.join(directory, lang, 'LC_MESSAGES')
-            mo_file = os.path.join(path, f"{domain}.mo")
-            if os.path.exists(mo_file):
-                supported_languages.add(lang)
-    if loc is None:
-        loc, encoding = get_locale()
-    else:
-        encoding = get_locale()[1]
-    if loc in supported_languages:
-        default_language = loc
-    else:
-        default_language = "en"
-    # Even if the default language is not supported, the encoding should
-    # be installed. Otherwise the Python installation is borked.
-    default_encoding = encoding
-    install_language(default_language)
-
-
-def install_language(language):
-    """Install translation service routines into default namespace."""
-    translator = get_translator(
-        default_domain, default_directory, languages=[get_lang(language)], fallback=True
-    )
-    do_unicode = True
-    translator.install(do_unicode)
-
-
-def get_translator(
-    domain,
-    directory,
-    languages=None,
-    translatorklass=Translator,
-    fallback=False,
-    fallbackklass=NullTranslator,
-):
-    """Search the appropriate GNUTranslations class."""
-    translator = gettext.translation(
-        domain,
-        localedir=directory,
-        languages=languages,
-        class_=translatorklass,
-        fallback=fallback,
-    )
-    if not isinstance(translator, gettext.GNUTranslations) and fallbackklass:
-        translator = fallbackklass()
-    return translator
-
-
-def get_lang(lang):
-    """Return lang if it is supported, or the default language."""
-    if lang in supported_languages:
-        return lang
-    return default_language
-
-
-def get_locale():
-    """Search the default platform locale and norm it.
-    @returns (locale, encoding)
-    @rtype (string, string)"""
-    try:
-        loc, encoding = locale.getdefaultlocale()
-    except ValueError:
-        # locale configuration is broken - ignore that
-        loc, encoding = None, None
-    if loc is None:
-        loc = "C"
-    else:
-        loc = norm_locale(loc)
-    if encoding is None:
-        encoding = "ascii"
-    return (loc, encoding)
-
-
-def norm_locale(loc):
-    """Normalize a locale."""
-    loc = locale.normalize(loc)
-    # split up the locale into its base components
-    pos = loc.find('@')
-    if pos >= 0:
-        loc = loc[:pos]
-    pos = loc.find('.')
-    if pos >= 0:
-        loc = loc[:pos]
-    pos = loc.find('_')
-    if pos >= 0:
-        loc = loc[:pos]
-    return loc
-
-
 def get_encoded_writer(out=sys.stdout, encoding=None, errors='replace'):
     """Get wrapped output writer with given encoding and error handling."""
     if encoding is None:

tests/__init__.py

@@ -34,7 +34,8 @@ class TestBase(unittest.TestCase):
         """Ensure the current locale setting is the default.
         Otherwise, warnings will get translated and will break tests."""
         super().setUp()
-        init_i18n(loc="C")
+        os.environ["LANG"] = "C"
+        init_i18n()
 
 
 def run(cmd, verbosity=0, **kwargs):