bug#64724: 30.0.50; Inconsistency between manual, comments in the code, and implementation of point adjustment

[Eli Zaretskii]

> From: Ihor Radchenko <yantar92@posteo.net>
> Cc: monnier@iro.umontreal.ca, 64724@debbugs.gnu.org
> Date: Fri, 21 Jul 2023 12:56:19 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> Please remember that info page was just one of the points I listed in
> >> the initial report.
> >
> > I must have missed them (even though I've skimmed the discussion again
> > now), so please point them out again.
> 
> Further, `set_point_both' contains the following comments:
> 
>         /* If the preceding character is both intangible and invisible,
>            and the invisible property is `rear-sticky', perturb it so
>            that the search starts one character earlier -- this ensures
>            that point can never move to the end of an invisible/
>            intangible/rear-sticky region.  */
>         charpos = adjust_for_invis_intang (charpos, -1, -1, 1);
>         <...>
>         /* If the following character is both intangible and invisible,
>            and the invisible property is `front-sticky', perturb it so
>            that the search starts one character later -- this ensures
>            that point can never move to the beginning of an
>            invisible/intangible/front-sticky region.  */
>         charpos = adjust_for_invis_intang (charpos, 0, 1, 1);
> 
> However, 'intanglible text property is, in fact, not necessary to
> trigger the adjustment.

Didn't we establish that set_point_both is not relevant to the
behavior you see, and in fact is a deprecated feature on its way out?