bug#67604: Motion problems with inline images

[Eli Zaretskii <eliz@gnu.org>]

> From: JD Smith <jdtsmith@gmail.com>
> Date: Sun, 3 Dec 2023 11:54:27 -0500
> 
> Following on from the recently fixed bug#67533, which related to incorrect pixel size measurements
> with inline images, one remaining issue, with that fix in place, relates to motion in buffers in visual line
> mode with inline images.  A video of the effect can be seen on the associated gist for bug#67533.
> 
> Here the issue is that next-line/forward-line/(vertical-motion 1) all skip from the Green inline SVG
> straight to the “JUMPS HERE” line, for certain frame widths (for me: 79 characters).  See
> reproduction code, below.  Depending on your font char size (mine is 7x14 pixels) this width may
> vary for you.  Note that multiple frame width produce the exact same wrapped appearance, but the
> motion bug shows up only for one of them.

I tried different frame widths, but couldn't reproduce the problem.
Not with the latest master branch, anyway, where I recently installed
the changes from bug#67533.

If someone can tell what frame width and default font height trigger
the problem, I will try to reproduce with those sizes.