Ensure nested elements inside inline comments are properly unescaped.

When inline Markdwon elements are nested, each nested level contains its
own placeholder. Therefore, when unescaping, the regex substitution needs
to be run again each nested level. As this is nested inside the match, it ensures
only one non-matching regex will be run in each instace.

Closes #1571.

Author: waylan

markdown/inlinepatterns.py

@@ -520,7 +520,8 @@ def get_stash(m: re.Match[str]) -> str:
             value = stash.get(id)
             if value is not None:
                 try:
-                    return self.md.serializer(value)
+                    # Ensure we don't have a placeholder inside a placeholder
+                    return self.unescape(self.md.serializer(value))
                 except Exception:
                     return r'\%s' % value
 

tests/test_syntax/inline/test_raw_html.py

@@ -34,3 +34,9 @@ def test_inline_html_backslashes(self):
 
     def test_noname_tag(self):
         self.assertMarkdownRenders('<span></></span>', '<p><span>&lt;/&gt;</span></p>')
+
+    def test_markdown_nested_in_inline_comment(self):
+        self.assertMarkdownRenders(
+            'Example: <!-- [**Bold link**](http://example.com) -->',
+            '<p>Example: <!-- <a href="http://example.com"><strong>Bold link</strong></a> --></p>'
+        )