Re: Redisplay slower in Emacs 28 than Emacs 27

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Tue, 08 Dec 2020 00:48:24 +0100
> Cc: Eli Zaretskii <eliz@gnu.org>, emacs-devel@gnu.org
> 
> +  (or (and cache
> +           (gethash specs find-image--cache))
> +      (let ((orig-specs specs)
> +            image)
> +        (while (and specs (null image))

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?