bug#9296: 24.0.50; next-line/prev-line on lines with images

[Eli Zaretskii <eliz@gnu.org>]

> From: Lars Magne Ingebrigtsen <larsi@gnus.org>
> Cc: 9296@debbugs.gnu.org
> Date: Sun, 14 Aug 2011 23:12:08 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > I can't reproduce this.  For me, `down' goes to the image in the line
> > below.  So we are at an impasse.  If you can tell me how to reproduce
> > this, perhaps by modifying the font or whatever, I can debug this;
> > otherwise, I cannot.
> 
> Could it possibly be an X vs Windows thing?

I very much doubt that: vertical cursor motion is handled entirely in
device-independent parts of the display engine.  The only
system-dependent issue here could be the pixel size of the font and of
the images, because the underlying code calculates in pixels.

> I'm testing with "emacs -Q" under Linux.

If it's "emacs -Q", how come you told a few messages back that column
60 is the column where text is truncated?  The default geometry sets
the frame width to 80 columns, AFAIK.

Are you sure there are no local changes in effect when you see the
problem?

> And the following form reliably says "55" for me with "emacs -Q"
> under Linux.

And what does it say in Emacs 23.3?  It doesn't say "0", does it?

Anyway, I spotted something that could explain what you see; please
try revision 105451.