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/)
