Re: [Qemu-devel] QEMU produces invalid JSON due to locale-dependent code

[Daniel P. Berrange]

On Mon, Aug 24, 2015 at 07:07:38PM +0200, Markus Armbruster wrote:
> Alberto Garcia <address@hidden> writes:
> 
> > On Mon 24 Aug 2015 12:05:02 PM CEST, Markus Armbruster wrote:
> >
> >>> This seems to happen because of GTK+ calling setlocale(). The easiest
> >>> solution is probably to call setlocale(LC_NUMERIC, "C") before
> >>> snprintf() (or at start-up ui/gtk.c), but opinions are welcome.
> >>
> >> A library calling setlocale() is a big no-no in my book.
> >>
> >> Overriding LC_NUMERIC as you propose should fix this particular bug.
> >>However, exposing unprepared code to locale is not a good idea for
> >>other categories as well.  LC_COLLATE and LC_CTYPE are even sneakier
> >>sources of bugs in my experience.  I'd really, really prefer to stay in
> >>the "C" locale *completely*.
> >
> > You can prevent GTK+ from calling setlocale() by using
> > gtk_disable_setlocale() before gtk_init(), but note that setlocale() is
> > needed for gettext.
> 
> We can
> 
> (A) Internationalize our complete code base
> 
> (B) Run in the C locale
> 
>     Breaks GTK's internationalization.
> 
> (C) Run in a mixed locale
> 
>     Whenever something breaks, we switch another LC_ to the C locale.
> 
>     Can partially break GTK's internationalization.
> 
> I happily concede that (A) would be best.  Until the manpower to pull it
> off appears, I recommend (B), because it's safer than (C), and avoids
> inconsistent localization, such as German messages combined with
> non-German number formatting.

It seems the only thing that we really care about being localized is
the messages catalogue, so the GTK UI gets internationalization in
its menus / dialogs / etc. As such I think that we should do the
opposite of (C). ie run every LC_* in the C locale, except for
LC_MESSAGES which we allow to be localized.

This avoids any unpredictable functional consequences (like number
formatting) while still giving user decent localization in the UI

Regards,
Daniel
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