bug#46552: 27.1; image-mode should not move current point

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: ynyaaa@gmail.com,  46552@debbugs.gnu.org
> Date: Tue, 16 Feb 2021 18:41:40 +0100
> 
> > IOW, from the user's POV, the image is a single "cell" on display, so
> > any forward movement of point ends up _after_ the image, where the
> > commands like '+' aren't supposed to work.
> 
> I think that sounds quite surprising.  There's nothing much to do in an
> image-mode buffer than interact with the image, and this makes
> interaction not work.

But so does "C-c C-c".  "If it hurts, don't do that."

More importantly, I think disabling the point adjustments will cause
very surprising behavior: it allows moving point many times (as many
as there are bytes in the image file) without any visible effect.
That's something we want very much to avoid, and it is the main reason
why we have this point-adjustment feature.  Disabling it is a
debugging tool, not something to show to users.