Re: [Bug report] Git incorrectly selects language in macos

[Nate Weaver <wevah@derailer.org>]

> On Jan 15, 2019, at 09:35:52, Nate Weaver <wevah@derailer.org> wrote:
> 
>> On Sep 16, 2018, at 02:15:33, Eric Sunshine <sunshine@sunshineco.com> wrote:
>> 
>> On Fri, Sep 14, 2018 at 10:20 PM Niko Dzhus <primenico@gmail.com> wrote:
>>> Looks like the issue appeared after updating git from brew.
>>> 
>>> A quick search revealed that brew changed how it builds git recently.
>>> I think, it just didn't include i18n by default before, so I never
>>> noticed this.
>>> 
>>> Anybody here familiar enough with the build process and dependencies
>>> of git to pinpoint what exactly is causing this and how to fix it?...
>> 
>> This problem is not specific to Git. Earlier in the thread, Ævar
>> asked[1] if the problem also occurs with other command-line programs,
>> and indeed it does. For instance, I tried with 'wget' installed via
>> brew, and it exhibits the same odd behavior. Ævar suggested that there
>> might be some magic special-casing English, which makes me wonder if
>> brew builds such magic into gettext(?) or if the magic is part of
>> MacOS itself.
>> 
>> [1]: https://public-inbox.org/git/87a7ojlp31.fsf@evledraar.gmail.com/
> 
> I discovered that moving/renaming /usr/local/share/locale made this
> issue go away for me. While 'de' and 'fr' have a git.mo file in their
> LC_MESSAGES subdirectory, there is no 'en' directory.
> 
> If I copy the 'fr' version to a newly-created 'en' directory, then all my
> git output is in French; my language order in System Preferences is
> English (US) -> German -> Japanese.
> 
> Not sure if this is gettext's or macOS's issue.
> 
> --Nate Weaver (Wevah)

Upon further digging, this is an issue in gettext's code on macOS:
The function _nl_language_preferences_default (in langprefs.c) specifically
breaks early when it sees the literal string "en" in the list (from the
"AppleLanguages" defaults key), but not when it gets "en-US", etc.

I.e., it doesn't check for a prefix.

This can be fixed (though there might be a better way) simply by replacing
both instances of

if (strcmp (buf, "en") == 0)

with

if (strncmp (buf, "en", 2) == 0)

in gettext's langprefs.c.