Re: display bug for empty lines in recent git snapshot

[Eli Zaretskii <eliz@gnu.org>]

> From: Giorgos Keramidas <keramida@ceid.upatras.gr>
> Cc: Tassilo Horn <tassilo@member.fsf.org>, emacs-devel@gnu.org
> Date: Wed, 17 Nov 2010 11:43:23 +0100
> 
> On Wed, 17 Nov 2010 10:31:08 +0100, Tassilo Horn <tassilo@member.fsf.org> wrote:
> > Hi Giorgos,
> >
> > I've already filed this as bug#7417.
> 
> The change that introduced this bug in my local mirror of the git trunk
> is one committed by Eli on Nov 13:

Yes, it's my bad, sorry.  Cursor positioning is a tricksy business,
with lots of different use-cases.  I guess I failed to test the TTY
display properly after this change.

> I think there's some exception we have to add here for newline
> characters, because they are treated as GLYPHLESS_DISPLAY_THIN_SPACE or
> as GLYPHLESS_DISPLAY_EMPTY_BOX with a width of 1 space, but I am not
> sure what the best way to do this would be.  Maybe Eli has a good idea
> of how this can be fixed?

No, this isn't the problem, I'm quite sure.

The problem is that I installed a fix for displaying glyphless
characters using the zero-width method (see the change in
set_cursor_from_row in the changeset), and that fix inadvertently
introduced this bug.

I will try to fix this as soon as possible.