Subject: bug#30902: 25.2; dired: image compression (png → jpg/jpeg)

From: Lars Ingebrigtsen <[email-masked]>
Date: Sun, 14 Jul 2019 16:21:22 +0200

Michael 2 <[email-masked]> writes:

> I praise to you because i want the variable:
> `dired-compress-files-alist' as a custom variable.
>
> Whololololo...
>
> I want to add my own compression-expressions. At the moment it is a
> normal global variable (defvar). And can't be accesed with M-x
> customize-variable.  My suggestion for compressing png-images would
> be:
>
>       `'(("\\.png\\.jpg\\'" . "convert %i %o"))'

I don't think that's appropriate as a default value for that variable,
because that's not compressing -- it's converting to a different format
from which the original can't be reconstructed.

And, in general, I don't feel it's very useful to make complex alists
like this into defcustoms, because it's so fiddly to get the syntax
right if you're not using an Emacs Lisp mode buffer.  So I'm closing
this bug report.

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