bug#69602: 29.1; Image :map should adjust with :scale and :rotation

[Eli Zaretskii]

> From: Joseph Turner <joseph@breatheoutbreathe.in>
> Cc: 69602@debbugs.gnu.org, stephen.berman@gmx.net, juri@linkov.net
> Date: Fri, 08 Mar 2024 00:39:16 -0800
> 
> > Are we sure no Lisp program out there would want the coordinates in
> > :map to remain unchanged under these transformation?  Maybe we should
> > add a variable to control this, so that the change could be truly
> > backward-compatible?
> 
> Good point.  Thanks!
> 
> What if explicitly passing :unscaled-map 'no-recalculate in
> `create-image' prevented :map from being recalculated later?

I think that's less desirable, since some images could be created
outside of control of a Lisp program that wants to control the
coordinates.

> If not, what kind of variable did you have in mind?  A special variable
> let-bound the call?  Or another argument to `create-image'?

I had in mind a special variable (we'd need to mention it in NEWS and
in the doc string of the relevant functions).  Adding an argument is a
heavier change, and I think it is not justified in this case, because
I do agree with you that most, if not all, applications would want the
coordinates to scale together with the image.

Thanks.