Subject: bug#38187: 27.0.50; No mouse-wheel scaling on images

From: Lars Ingebrigtsen <[email-masked]>
Date: Thu, 21 Nov 2019 22:26:30 +0100

Juri Linkov <[email-masked]> writes:

> BTW, while testing it for image scaling on a quite small image file,
> Emacs consumed several GB of all available memory and almost all swap,
> before I noticed and evaluated M-: (clear-image-cache) that freed memory.
>
> Memory leak?

No, it's just that Emacs' image cache is very primitive.  You can easily
get Emacs to go out-of-memory by just doing a

(dolist (file (directory-files dir-with-lots-of-images))
  (erase-buffer)
  (insert-image (create-image file)))

You get the same effect by altering the scaling factor, I think?  Each
scaled image is cached?  So by rolling the wheel ten clicks you get ten
cached copies of the image.

A better eviction algorithm would be nice.

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