bug#29279: Sharing the margins

[Eli Zaretskii]

> Date: Tue, 14 Nov 2017 10:54:45 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: 29279@debbugs.gnu.org
> 
>  > Yes.  But using margins from Emacs internals means that the
>  > window-parameters which hold the column specs will change behind the
>  > back of the Lisp applications, which I'm not sure is a Good Thing.
> 
> I can see no harm in that.

It's...unexpected.