bug#65908: 29.1.50; Emacs 29 regresses on macOS

[Alan Third]

On Thu, Oct 05, 2023 at 10:52:21AM +0200, Gerd Möllmann wrote:
> Conclusion so far, for me,
> 
> - don't selocale in ns_init_locale, only setenv LANG, or set LC_CTYPE,
>   maybe.

setlocale in ns_init_locale is only there to check if the locale is
valid, it resets it back to its initial value at the end.

> - localeIndentifier is wrong for mixed cases like "en_DE".

There was some trouble with warning messages in the terminal when
using an invalid locale ID (see bug#51321), but that may only be
because Daniel had changed the code to set LC_ALL instead of LANG.

I preferred setting LANG anyway because it acts as a fallback, and
this is pretty much intended as a fallback, anything else explicitly
set will override it.

Out of interest, when is it slow? Is it when we have an invalid locale
ID?
-- 
Alan Third