bug#59141: 28.1.90; Face :extend when all the line but trailing \n is invisible

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: kevin.legouguec@gmail.com,  59141@debbugs.gnu.org,
>   abdo.haji.ali@gmail.com,  yantar92@posteo.net
> Date: Tue, 22 Nov 2022 21:16:27 +0200
> 
> > Does the below produce what you want?
> >
> >   (progn
> >     (insert "ab")
> >     (let ((o (make-overlay 2 3)))
> >       (overlay-put o 'after-string "!"))
> >     (let ((o (make-overlay 2 3)))
> >       (overlay-put o 'invisible t)))
> 
> Thanks, this is a possibility.  Maybe not easy to use
> since for an ellipsis overlay will need to get the boundaries
> of the invisible outline overlay.

I don't think you need the exact boundaries.  All you need is to make sure
the START of the after-string overlay is in invisible text.  It doesn't
matter where its END is.