[BUG] Face attribute customization is ignored [9.5.5 (9.5.5-gbe2246 @ ~/.emacs.d/straight/build/org/)]

[David Vicente]

Starting with:
    $ emacs -Q


and evaluating

(require 'org)

(set-face-attribute 'org-block nil :extend nil :background "snow2")
(set-face-attribute 'org-block-begin-line nil :extend nil :background 
"snow2")
(set-face-attribute 'org-block-end-line nil :extend nil :background "snow2")

(org-mode)

If we now write something like:


#+BEGIN_SRC
(+ 1 2)
#+END_SRC

The attribute customization of org-block-begin-line and 
org-block-end-line is ignored, i.e, the :extend attribute gets 
overwritten when we start org-mode and ends up with value t.

After inspecting the source code I suspect that it might have something 
to do with org-fontify-whole-block-delimiter-line...

Thanks

Emacs  : GNU Emacs 28.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 
3.24.33, cairo version 1.17.6)
 of 2022-04-27
Package: Org mode version 9.5.5 (9.5.5-gbe2246 @ 
~/.emacs.d/straight/build/org/)