Re: Redisplay slower in Emacs 28 than Emacs 27

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Eli Zaretskii <eliz@gnu.org> writes:
>
>> What will this do when the image file on disk changes?  AFAIU, the
>> current implementation will use the new image for the tool bar on the
>> next redisplay opportunity, but this change will make us continue
>> using the cached one?
>
> Yes.  Changing toolbar image file contents is such a rare action that
> it's not worth making Emacs recheck them on redisplay.

Sorry, thinko -- what this new cache does is cache the image locations,
not the contents.  So if you add a new search.xpm somewhere in the load
path, the toolbar will continue using the previously found location.

If you change the image on file, there's no change from how this worked
in Emacs 27 -- Emacs will not show the new image, because it never
checks whether an image file is newer than what's in the image cache.

So before as now, you have to clear the image cache in that case.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no