Re: Patch for reftex.el: master or release branch?

[Eli Zaretskii <eliz@gnu.org>]

> From: Arash Esbati <arash@gnu.org>
> Date: Wed, 14 Dec 2022 14:21:23 +0100
> 
> Dear maintainers,
> 
> I have the following patch for reftex.el fixing AUCTeX bug#59638.  This
> issue was introduced with commit 1e8bb313ea:
> 
> --8<---------------cut here---------------start------------->8---
> diff --git a/lisp/textmodes/reftex.el b/lisp/textmodes/reftex.el
> index f815419ea4..126b3777f5 100644
> --- a/lisp/textmodes/reftex.el
> +++ b/lisp/textmodes/reftex.el
> @@ -1004,10 +1004,13 @@ reftex-compile-variables
>                    reftex-section-levels))
> 
>      ;; Calculate the regular expressions
> -    (let* (
> -;          (wbol "\\(\\`\\|[\n\r]\\)[ \t]*")
> -           (wbol "\\(^\\)%?[ \t]*") ; Need to keep the empty group because
> -                                    ; match numbers are hard coded
> +    (let* (;; (wbol "\\(\\`\\|[\n\r]\\)[ \t]*")
> +           ;; Need to keep the empty group because match numbers are
> +           ;; hard coded
> +           (wbol (concat "\\(^\\)"
> +                         (when (string-suffix-p ".dtx" (buffer-file-name) t)
> +                           "%")
> +                         "[ \t]*"))
>             (label-re (concat "\\(?:"
>                              (mapconcat #'identity reftex-label-regexps "\\|")
>                              "\\)"))
> --8<---------------cut here---------------end--------------->8---
> 
> Can you please tell me if this should go to master or emacs-29 branch?

How safe is the change?  If it is safe enough, emacs-29 is fine.

Tassilo, WDYT about the safety of the patch and/or about the urgency
to have the fix?