bug#65908: 29.1.50; Emacs 29 regresses on macOS

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: Eli Zaretskii <eliz@gnu.org>,  gregory@heytings.org,
>   65908@debbugs.gnu.org,  stefankangas@gmail.com,  ccsmile2008@outlook.com
> Date: Thu, 05 Oct 2023 15:18:42 +0200
> 
> I'd like to propose the attached patch for problem of invalid LANG
> setting.  This simply falls back to "en_US.UTF-8" if LANG isn't valid,
> or something valid can't be deduced from the locale.

Why is it reasonable to force the UTF-8 codeset as the fallback?

What about having a variable exposed to Lisp that allows the users to
control the fallback value of LANG?