Process HTML comments as markdown in 'escape' safe mode

CHANGES.md

@@ -5,6 +5,7 @@
 - [pull #519] Add support for custom extras
 - [pull #519] Drop Python 3.5 support
 - [pull #568] Add `prepend` arg to toc extra (#397)
+- [pull #569] Process HTML comments as markdown in 'escape' safe mode
 - [pull #570] Fix syntax warnings in test suite
 
 

lib/markdown2.py

@@ -1264,15 +1264,30 @@ def _is_code_span(index, token):
 
             return re.match(r'<code>md5-[A-Fa-f0-9]{32}</code>', ''.join(peek_tokens))
 
+        def _is_comment(token):
+            if self.safe_mode == 'replace':
+                # don't bother processing each section of comment in replace mode. Just do the whole thing
+                return
+            return re.match(r'(<!--)(.*)(-->)', token)
+
+        def _hash(token):
+            key = _hash_text(token)
+            self.html_spans[key] = token
+            return key
+
         tokens = []
         split_tokens = self._sorta_html_tokenize_re.split(text)
         is_html_markup = False
         for index, token in enumerate(split_tokens):
             if is_html_markup and not _is_auto_link(token) and not _is_code_span(index, token):
-                sanitized = self._sanitize_html(token)
-                key = _hash_text(sanitized)
-                self.html_spans[key] = sanitized
-                tokens.append(key)
+                is_comment = _is_comment(token)
+                if is_comment:
+                    tokens.append(_hash(self._sanitize_html(is_comment.group(1))))
+                    # sanitise but leave comment body intact for further markdown processing
+                    tokens.append(self._sanitize_html(is_comment.group(2)))
+                    tokens.append(_hash(self._sanitize_html(is_comment.group(3))))
+                else:
+                    tokens.append(_hash(self._sanitize_html(token)))
             else:
                 tokens.append(self._encode_incomplete_tags(token))
             is_html_markup = not is_html_markup

test/tm-cases/escape_html_comments_safe_mode.html

@@ -0,0 +1,3 @@
+<p><em>foo</em> &lt;!-- <em>bar</em></p>
+
+<p><em>foo</em> &lt;!-- <em>bar</em> --&gt;</p>

test/tm-cases/escape_html_comments_safe_mode.opts

@@ -0,0 +1 @@
+{'safe_mode': 'escape'}

test/tm-cases/escape_html_comments_safe_mode.text

@@ -0,0 +1,3 @@
+*foo* <!-- *bar*
+
+*foo* <!-- *bar* -->