i18n: updated outdated comment

mercurial/i18n.py

@@ -1,48 +1,51
 # 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, incorporated herein by reference.
 
 import encoding
 import gettext, sys, os
 
 # modelled after templater.templatepath:
 if hasattr(sys, 'frozen'):
     module = sys.executable
 else:
     module = __file__
 
 base = os.path.dirname(module)
 for dir in ('.', '..'):
     localedir = os.path.normpath(os.path.join(base, dir, 'locale'))
     if os.path.isdir(localedir):
         break
 
 t = gettext.translation('hg', localedir, fallback=True)
 
 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:
         return message
 
-    # We cannot just run the text through encoding.tolocal since that
-    # leads to infinite recursion when encoding._encoding is invalid.
     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.
         u = t.ugettext(message)
         return u.encode(encoding.encoding, "replace")
     except LookupError:
         return message
 
 _ = gettext