> From: Carsten Dominik <carsten.dominik@gmail.com>
> Date: Sat, 10 Aug 2019 16:17:18 +0200
> Cc: Nicolas Goaziou <mail@nicolasgoaziou.fr>, rotim.davor@gmail.com, Ergus <spacibba@aol.com>,
>       36858@debbugs.gnu.org
>
>  So if you think the current display looks good, how about making it
>  optional?  Then this could be turned off to avoid the inconsistent
>  display in those use cases where it matters.
>
> It is possible to make it optional.  However, it seems to me that this is a bug in the display engine that should
> be fixed anyway, don't you agree?

It's not a bug, it's how the display engine was designed to work.  If
we decide to change the design, and stop extending the face of the
last character to the edge of the window, when the face covers the
newline, then the issue with display-fill-column-indicator-mode in Org
mode will also go away.  But we haven't yet made such a decision, see
the discussion which starts here:

  https://lists.gnu.org/archive/html/emacs-devel/2019-08/msg00132.html