From d4de627de25b381813094896d378db67755b0a34 Mon Sep 17 00:00:00 2001
From: Jason Blevins <jblevins@xbeta.org>
Date: Fri, 10 Nov 2017 15:34:41 -0500
Subject: [PATCH] Font lock for HTML entities

---
 CHANGES.md             |  2 ++
 markdown-mode.el       |  9 +++++++++
 tests/markdown-test.el | 30 ++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/CHANGES.md b/CHANGES.md
index 72a95d7..e02b28f 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -14,6 +14,8 @@
         Alexis Gallagher for a patch.  ([GH-272][], [GH-274][])
     -   Added pipe table editing features.  Thanks to Dmitry Safronov
         for a patch.  ([GH-171][], [GH-266][])
+    -   Font lock for HTML entities, with a new face
+        `markdown-html-entity-face`.
 
 *   Improvements:
 
diff --git a/markdown-mode.el b/markdown-mode.el
index 8e8415e..251883e 100644
--- a/markdown-mode.el
+++ b/markdown-mode.el
@@ -1886,6 +1886,10 @@ Group 2 matches the opening square bracket.
 Group 3 matches the footnote text, without the surrounding markup.
 Group 4 matches the closing square bracket.")
 
+(defconst markdown-regex-html-entity
+  "\\(&#?[[:alnum:]]+;\\)"
+  "Regular expression for matching HTML entities.")
+
 
 ;;; Syntax ====================================================================
 
@@ -2763,6 +2767,11 @@ For example, this applies to plain angle bracket URLs:
   "Face for horizontal rules."
   :group 'markdown-faces)
 
+(defface markdown-html-entity-face
+  '((t (:inherit font-lock-variable-name-face)))
+  "Face for HTML entities."
+  :group 'markdown-faces)
+
 (defcustom markdown-header-scaling nil
   "Whether to use variable-height faces for headers.
 When non-nil, `markdown-header-face' will inherit from
diff --git a/tests/markdown-test.el b/tests/markdown-test.el
index bfb9cd3..036e587 100644
--- a/tests/markdown-test.el
+++ b/tests/markdown-test.el
@@ -3107,6 +3107,36 @@ note.]  And then you can close it and continue writing."
 across blocks]"
     (markdown-test-range-has-face (point-min) (point-max) nil)))
 
+(ert-deftest test-markdown-font-lock/html-entity-named ()
+  "Test basic font-lock support for named HTML entities."
+  (markdown-test-string "&nbsp;"
+    (markdown-test-range-has-face 1 6 'markdown-html-entity-face)))
+
+(ert-deftest test-markdown-font-lock/html-entity-hex ()
+  "Test basic font-lock support for hexadecimal HTML entities."
+  (markdown-test-string "&#x272a;"
+    (markdown-test-range-has-face 1 8 'markdown-html-entity-face)))
+
+(ert-deftest test-markdown-font-lock/html-entity-decimal ()
+  "Test basic font-lock support for decimal HTML entities."
+  (markdown-test-string "&#9;"
+    (markdown-test-range-has-face 1 4 'markdown-html-entity-face)))
+
+(ert-deftest test-markdown-font-lock/html-entity-in-inline-code ()
+  "Test that HTML entities are not matched inside inline code."
+  (markdown-test-string "`&#9;`"
+    (markdown-test-range-has-face 1 1 'markdown-markup-face)
+    (markdown-test-range-has-face 2 5 'markdown-inline-code-face)
+    (markdown-test-range-has-face 6 6 'markdown-markup-face)
+    (should-not (markdown-range-property-any 1 6 'face '(markdown-html-entity-face)))))
+
+(ert-deftest test-markdown-font-lock/html-entity-in-gfm-code-block ()
+  "Test that HTML entities are not matched inside GFM code blocks."
+  (markdown-test-string "```\n&nbsp;\n&#x272a;\n&#9;\n```"
+    (should-not
+     (markdown-range-property-any
+      (point-min) (point-max) 'face '(markdown-html-entity-face)))))
+
 ;;; Markdown Parsing Functions:
 
 (ert-deftest test-markdown-parsing/extend-region-function ()
-- 
2.11.4.GIT