Subject: Re: bug#64391: buffer narrowing slowdown regression in emacs 29

From: Eli Zaretskii <[email-masked]>
Date: Sun, 09 Jul 2023 22:03:41 +0300

> Date: Sun, 09 Jul 2023 18:03:02 +0000
> From: Gregory Heytings <[email-masked]>
> cc: [email-masked], [email-masked], [email-masked], 
>     [email-masked], [email-masked]
> 
> >> +When the optional argument @var{label}, which is evaluated to get the
> >> +label to use and must not be @code{nil},
> >
> > What "must not be nil": the label or the result of its evaluation?
> >
> 
> The result of the evaluation of the label argument.  I don't know how to 
> make this clearer.

Instead of "must not be nil", say "must not yield nil".