Subject: Re: bug#23574: 24.5; Overzealous underlining in emacs-nox

From: Eli Zaretskii <[email-masked]>
Date: Sun, 05 Jun 2016 20:56:28 +0300

> From: Noam Postavsky <[email-masked]>
> Date: Sun, 5 Jun 2016 13:05:53 -0400
> Cc: John Mastro <[email-masked]>, [email-masked], [email-masked]
> 
> On Sun, Jun 5, 2016 at 11:54 AM, Eli Zaretskii <[email-masked]> wrote:
> > We always try to make the empty space
> > after the end of a screen line have the same face as the last
> > character of that line.
> 
> Just to clarify, "last character of that line" refers to the newline
> character or the one before it?

The last displayed character of the line.  The newline is not
displayed, in the sense that it has no glyph, so it can have no face.

> > While it should be
> > possible to have GUI frames display underline all the way to window
> > edge, no one has ever requested that, so we didn't bother.
> 
> I think this would have been useful for magit to simplify the use of
> overlays to display the region with horizontal lines.

This is doable (and in fact we already do that in R2L paragraphs,
which you can observe if you change the recipe's text to use R2L
characters).  But note that the OP in this bug report wants the exact
opposite: to NOT have the underlining extended on TTYs.  So clearly
there's no "one size fits all" solution here.

> In http://debbugs.gnu.org/cgi/bugreport.cgi?bug=21468#43 you
> suggested a way using :align-to which turned out to have a bunch of
> complications and magit ended up not using it (see
> https://github.com/magit/magit/pull/2293).

Did you try using the box attribute of a face?