[nongnu] elpa/markdown-mode 4fc65528b9 1/2: Don't load language mode if it is not in `auto-mode-alist`

[ELPA Syncer]

branch: elpa/markdown-mode
commit 4fc65528b908429cfb3321a42e168a0977250c15
Author: Shohei YOSHIDA <syohex@gmail.com>
Commit: Shohei YOSHIDA <syohex@gmail.com>

    Don't load language mode if it is not in `auto-mode-alist`
---
 CHANGES.md             |  2 ++
 markdown-mode.el       | 10 +++++++++-
 tests/markdown-test.el |  9 +++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/CHANGES.md b/CHANGES.md
index e554571a49..3957e0175f 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -22,6 +22,7 @@
     - Highlight autolinks if a scheme is valid and it is not registered in 
markdown-uri-types
       [GH-743][]
     - Improve horizontal rule rendering in `markdown-view-mode` [GH-753][]
+    - Don't load major-mode if it isn't in `auto-mode-alist`[GH-761][]
 
 *   Bug fixes:
     - Don't override table faces by link faces [GH-716][]
@@ -42,6 +43,7 @@
   [gh-743]: https://github.com/jrblevin/markdown-mode/issues/743
   [gh-747]: https://github.com/jrblevin/markdown-mode/issues/747
   [gh-753]: https://github.com/jrblevin/markdown-mode/issues/753
+  [gh-761]: https://github.com/jrblevin/markdown-mode/issues/761
   [gh-762]: https://github.com/jrblevin/markdown-mode/issues/762
 
 
diff --git a/markdown-mode.el b/markdown-mode.el
index 00918a23d4..9d7bb31d9c 100644
--- a/markdown-mode.el
+++ b/markdown-mode.el
@@ -8779,7 +8779,7 @@ mode to use is `tuareg-mode'."
   "Return major mode that should be used for LANG.
 LANG is a string, and the returned major mode is a symbol."
   (cl-find-if
-   'fboundp
+   #'markdown--lang-mode-predicate
    (nconc (list (cdr (assoc lang markdown-code-lang-modes))
                 (cdr (assoc (downcase lang) markdown-code-lang-modes)))
           (and (fboundp 'treesit-language-available-p)
@@ -8791,6 +8791,14 @@ LANG is a string, and the returned major mode is a 
symbol."
            (intern (concat lang "-mode"))
            (intern (concat (downcase lang) "-mode"))))))
 
+(defun markdown--lang-mode-predicate (mode)
+  (and mode
+       (fboundp mode)
+       ;; https://github.com/jrblevin/markdown-mode/issues/761
+       (cl-loop for pair in auto-mode-alist
+                for func = (cdr pair)
+                thereis (and (atom func) (eq mode func)))))
+
 (defun markdown-fontify-code-blocks-generic (matcher last)
   "Add text properties to next code block from point to LAST.
 Use matching function MATCHER."
diff --git a/tests/markdown-test.el b/tests/markdown-test.el
index 000974653e..dea5d98075 100644
--- a/tests/markdown-test.el
+++ b/tests/markdown-test.el
@@ -4306,6 +4306,15 @@ x: x
     (should (string-equal (markdown-code-block-lang
                            '(83 . markdown-tilde-fence-begin)) "bash"))))
 
+(ert-deftest test-markdown-parsing/get-lang-mode ()
+  "Test `markdown-get-lang-mode'.
+Do not load major-mode function if it isn't in auto-mode-alist.
+Details: https://github.com/jrblevin/markdown-mode/issues/761";
+  (should (eq (markdown-get-lang-mode "emacs-lisp") 'emacs-lisp-mode))
+
+  (let ((auto-mode-alist nil))
+    (should (null (markdown-get-lang-mode "emacs-lisp")))))
+
 (ert-deftest test-markdown-parsing/code-block-lang-period ()
   "Test `markdown-code-block-lang' when language name begins with a period."
   (markdown-test-string "~~~ { .ruby }