[PATCH] [FR] Fontifying src-blocks with no language specified

[Ihor Radchenko]

carsten@kragelund.me writes:

> Fontifying src-blocks with a missing language would allow being able to 
> theme src-blocks without having the unthemed text of languages fallback 
> to whatever color the src-blocks are set to.
> I envision this could be done with an empty string in 
> org-src-block-faces.

I do not see much problem adding this.
See the attached patch.

>From 9c9fa52b934390b9b07648fdf3a31c4baebac551 Mon Sep 17 00:00:00 2001
Message-Id: 
<9c9fa52b934390b9b07648fdf3a31c4baebac551.1676636352.git.yantar92@posteo.net>
From: Ihor Radchenko <yantar92@posteo.net>
Date: Fri, 17 Feb 2023 15:17:04 +0300
Subject: [PATCH] org-fontify-meta-lines-and-blocks-1: Fontify src blocks
 without lang

* lisp/org.el (org-fontify-meta-lines-and-blocks-1): Allow fontifying
src blocks with language specification missing.
* lisp/org-src.el (org-src-block-faces): Clarify in the docstring that
"" language name referes to src blocks with no language.  Remove
redundant :version tag.
* etc/ORG-NEWS (~org-src-block-faces~ now accepts empty string ~""~ as
language name): Announce the change.

Link: 99388ff3711696091f0312a5c3f0bcbd@kragelund.me">https://orgmode.org/list/99388ff3711696091f0312a5c3f0bcbd@kragelund.me
---
 etc/ORG-NEWS    | 15 +++++++++++++++
 lisp/org-src.el |  4 ++--
 lisp/org.el     |  2 +-
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 87ecd77cd..5ab8d62c7 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -24,6 +24,21 @@ consider 
[[https://gitlab.com/jackkamm/ob-python-mode-mode][ob-python-mode-mode]
 has been ported to.
 
 ** New and changed options
+*** ~org-src-block-faces~ now accepts empty string ~""~ as language name
+
+It is now possible to customize face of source blocks without language 
specifier.
+
+: #+begin_src
+: Source block with no language
+: #+end_src
+
+For example, to set ~highlight~ face, use
+
+#+begin_src emacs-lisp
+(setq org-src-fontify-natively t)
+(add-to-list 'org-src-block-faces '(("" highlight))
+#+end_src
+
 *** New escape in ~org-beamer-environments-extra~ for labels in Beamer export
 The escape =%l= in ~org-beamer-environments-extra~ inserts the label
 obtained from ~org-beamer--get-label~.  This is added to the default
diff --git a/lisp/org-src.el b/lisp/org-src.el
index 9e4392811..2fab4020d 100644
--- a/lisp/org-src.el
+++ b/lisp/org-src.el
@@ -233,7 +233,8 @@ (defcustom org-src-block-faces nil
 
      (\"language\" FACE)
 
-Where FACE is either a defined face or an anonymous face.
+Where FACE is either a defined face or an anonymous face.  Empty
+language string refers to source blocks without specified language.
 
 For instance, the following would color the background of
 emacs-lisp source blocks and python source blocks in purple and
@@ -247,7 +248,6 @@ (defcustom org-src-block-faces nil
                        (choice
                         (face :tag "Face")
                         (sexp :tag "Anonymous face"))))
-  :version "26.1"
   :package-version '(Org . "9.0"))
 
 (defcustom org-src-tab-acts-natively t
diff --git a/lisp/org.el b/lisp/org.el
index 4d12084d9..777626dce 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -5409,7 +5409,7 @@ (defun org-fontify-meta-lines-and-blocks-1 (limit)
            (org-remove-flyspell-overlays-in beg bol-after-beginline)
            (org-remove-flyspell-overlays-in nl-before-endline end-of-endline)
            (cond
-            ((and lang (not (string= lang "")) org-src-fontify-natively)
+            (org-src-fontify-natively
              (save-match-data
                 (org-src-font-lock-fontify-block lang block-start block-end))
              (add-text-properties bol-after-beginline block-end '(src-block 
t)))
-- 
2.39.1


-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>