bug#34639: 26.1; Custom themes break terminal when switching to org-mode

[Eli Zaretskii]

> From: Richard Stallman <rms@gnu.org>
> Cc: contovob@tcd.ie, kisik21@fireburn.ru, 34639@debbugs.gnu.org
> Date: Wed, 27 Feb 2019 22:42:49 -0500
> 
>   > The main (perhaps the only) one is that linum.el displays line numbers
>   > in the display margin, whereas the native line numbers are displayed
>   > in the text area.
> 
> Would it be difficult to add (in native line numbers) the option to put
> them in the display margin?

It's not easy, but should be possible, of course.  However, I don't
want to do that at this time, because we don't have any way of letting
more than one feature use the display margins without interfering with
one another.  Until we have an infrastructure in place to allow such
sharing of the margins, I firmly believe that core features should not
usurp the display margins, and will object to any core feature that
tries.