bug#67604: Motion problems with inline images

[JD Smith]

> On Dec 4, 2023, at 1:20 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: JD Smith <jdtsmith@gmail.com>
>> Date: Mon, 4 Dec 2023 12:44:45 -0500
>> Cc: 67604@debbugs.gnu.org
>> 
>> Wonders never cease.  I just picked an 8x16 font and it worked fine, finding 
>> the bug at offset=2 (i.e. red svg=148 pixels wide). This was using the build 
>> from this morning with your recent xdisp.c fix.  To be sure we’re on the 
>> same page, I’ve included again the test code below.
> 
> Now I run it and I get
> 
>   Found Bug at offset -6 = 140 pixels
> 
> but the problem with cursor jumping to "JUMPS HERE" still doesn't
> happen.


OK great.  Is it possible at offset = -6 = 140 pixels the green image has 
wrapped back onto line 1?  That’s a “false positive” bug.  The layout after 
my/find-skip-bug has found the magic width must look as in my prior screenshot 
(with green image at the beginning of screen line 2) or it’s not a real bug.

If it does look correct, from (point-min), any pair of next-line or 
(vertical-motion 1), should bypass scene line 3 = "pulvinar nibh" and land on 
screen line 4 = "JUMPS HERE", as that’s the literal test find-skip-bug performs!