Subject: Re: bug#53294: 29.0.50; Indirect font changes incorrectly affecting original buffer

From: Anders Johansson <[email-masked]>
Date: Wed, 16 Feb 2022 18:41:15 +0100

Hi,

Stefan wrote:
> I think `mapcar #'copy-sequence` is slightly more correct than
> `copy-tree`,

This gives me  "Wrong type argument: listp, mini-modeline-mode-line-active"
For a face-remapping-alist that looks like:
((mode-line-active . mini-modeline-mode-line-active)
 (mode-line-inactive . mini-modeline-mode-line-inactive))

According to my reading of the docstring of face-remapping-alist, this
should be allowed, and does work (except for indirect buffers perhaps)

face-remap-add-relative would generate:
((mode-line-active mini-modeline-mode-line-active)
 (mode-line-inactive mini-modeline-mode-line-inactive))

mini-modeline (https://github.com/kiennq/emacs-mini-modeline/) sets
face-remapping-alist directly for various reasons. I guess this is not
really recommended. But this fix seems to cause problems in an
otherwise "correct" use of face-remapping-alist.

Best,
Anders Johansson