From 1bd23dd102e8e264a45c5b69208a5b2fdc0be55b Mon Sep 17 00:00:00 2001
From: Shohei YOSHIDA <syohex@gmail.com>
Date: Mon, 7 Aug 2023 11:27:36 +0900
Subject: [PATCH] Consider major-mode-remap-alist to determine major-mode

---
 CHANGES.md             |  2 ++
 markdown-mode.el       | 14 ++++++++++----
 tests/markdown-test.el |  7 +++++++
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index d4f33f82..8d3186bc 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -26,6 +26,7 @@
     - 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][]
     - Improve `markdown-insert-table` prompt message [GH-771][]
+    - Consider `major-mode-remap-alist` to determine major-mode for code blocks [GH-787][]
 
 *   Bug fixes:
     - Don't override table faces by link faces [GH-716][]
@@ -57,6 +58,7 @@
   [gh-774]: https://github.com/jrblevin/markdown-mode/issues/774
   [gh-778]: https://github.com/jrblevin/markdown-mode/issues/778
   [gh-786]: https://github.com/jrblevin/markdown-mode/pull/786
+  [gh-787]: https://github.com/jrblevin/markdown-mode/issues/787
 
 # Markdown Mode 2.5
 
diff --git a/markdown-mode.el b/markdown-mode.el
index e0192b92..4af2fd56 100644
--- a/markdown-mode.el
+++ b/markdown-mode.el
@@ -8843,10 +8843,16 @@ LANG is a string, and the returned major mode is a symbol."
 (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)))))
+       (or
+        ;; https://github.com/jrblevin/markdown-mode/issues/787
+        ;; major-mode-remap-alist was introduced at Emacs 29.1
+        (cl-loop for pair in (bound-and-true-p major-mode-remap-alist)
+                 for func = (cdr pair)
+                 thereis (and (atom func) (eq mode func)))
+        ;; 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.
diff --git a/tests/markdown-test.el b/tests/markdown-test.el
index 50862df4..f29f2060 100644
--- a/tests/markdown-test.el
+++ b/tests/markdown-test.el
@@ -4367,6 +4367,13 @@ Details: https://github.com/jrblevin/markdown-mode/issues/761"
   (let ((auto-mode-alist nil))
     (should (null (markdown-get-lang-mode "emacs-lisp")))))
 
+(ert-deftest test-markdown-parsing/get-lang-mode-from-remap-alist ()
+  "Test `markdown-get-lang-mode' from major-mode-remap-alist.
+Details: https://github.com/jrblevin/markdown-mode/issues/787"
+  (when (fboundp 'treesit-available-p)
+    (let ((major-mode-remap-alist '((python-mode . python-ts-mode))))
+      (should (eq (markdown-get-lang-mode "python") 'python-ts-mode)))))
+
 (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 }