bug#37774: 27.0.50; new :extend attribute broke visuals of all themes and other packages

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Cc: andreyorst@gmail.com,  spacibba@aol.com,  37774@debbugs.gnu.org
> Date: Thu, 17 Oct 2019 18:18:23 +0200
> 
> > What is a "rectangular context"?  I'm not sure I understand the exact
> > meaning of that.
> 
> I mean the use cases shown by Andrey Orst. Maybe "rectangular context"
> is wrong wording; I thought it is obvious what's meant.

Ah, okay.  I thought you had more to add to that.