Re: master 2ef6f943abd: Add option to control default outlining in 'C-h b'

[Eli Zaretskii <eliz@gnu.org>]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: Michael Heerdegen <michael_heerdegen@web.de>,  emacs-devel@gnu.org,
>  Matthias Meulien <orontee@gmail.com>
> Date: Tue, 25 Apr 2023 10:25:51 +0200
> 
> >>>>> On Tue, 25 Apr 2023 09:45:36 +0300, Eli Zaretskii <eliz@gnu.org> said:
> 
>     Eli> Feel free to suggest a better tag, TIA.  Bonus points for untangling
>     Eli> the IMNSHO confusing documentation of outline-default-rules in these
>     Eli> areas (e.g., what does "function is expected to toggle the heading
>     Eli> visibility" even mean??) and fixing that and the related tags as well.
>     Eli> I simply had no time for that, sorry, and saying just "Custom
>     Eli> function" without any hint what that function should do seemed like a
>     Eli> bad idea.
> 
> The custom function is just funcallʼed, which is somewhat unfriendly,
> since it forces the user to understand the details of how to hide
> headings, which are not documented (what happens if the custom
> function does nothing?). A predicate function would be more useful.
> 
> This code and the defcustom is new in emacs-29, so we can still change
> it to be a predicate instead. At least we should document is better

Agreed.  Patches welcome.