Subject: Re: bug#74091: 31.0.50; string-pixel-width in mode line disables region

From: Eli Zaretskii <[email-masked]>
Date: Sat, 09 Nov 2024 20:14:43 +0200

> From: Stefan Monnier <[email-masked]>
> Cc: [email-masked],  [email-masked]
> Date: Sat, 09 Nov 2024 13:06:13 -0500
> 
> AFAICT the problem is new with the addition of the `kill-permanent`
> arg to `kill-all-local-variables`.
> 
> Here's an example of a problem:
> 
>     src/emacs -Q --batch --eval '(message "%s" (list (setq-default foo nil) (setq-local foo t) (kill-all-local-variables t) (local-variable-p `foo) foo (default-value `foo) (with-temp-buffer foo) foo))'
> 
> =>
> 
>     (nil t nil t t nil nil nil)
> 
> If we call `kill-all-local-variables` without the additional argument, we
> get the correct answer:
> 
>     (nil t nil nil nil nil nil nil)

This feature was introduced in Emacs 29, so we should preferably fix
it in Emacs 30.  Any suggestions?