Unescape backslash-escaped quotes in link and image titles

CHANGES.md

@@ -2,6 +2,7 @@
 
 ## python-markdown2 2.5.6 (not yet released)
 
+- [pull #778] Fix backslash-escaped quotes in link and image titles being rendered as a literal `"`
 - [pull #762] Speed up documents with many links by skipping the backslash-escape scan for text without a backslash
 - [pull #748] Speed up `_unescape_special_chars` by skipping text with no hashes and dropping the full-text comparison per pass (#635)
 - [pull #749] URL-encode destinations generated by the `link-patterns` extra (#55)

lib/markdown2.py

@@ -3423,6 +3423,9 @@ def run(self, text: str):
                 if self.md.safe_mode:
                     # expose span contents for escaping - fix #691, #703
                     title = self.md._unhash_html_spans(title, spans=True, code=True)
+                # A backslash-escaped quote is just a quote. Left in, `\"` becomes `\"`, which the
+                # escaped-ampersand handling then turns into a literal `"` in the title.
+                title = title.replace('\\"', '"').replace("\\'", "'")
                 title = (
                     _xml_escape_attr(title)
                     .replace('*', self.md._escape_table['*'])

test/tm-cases/link_title_escaped_quotes.html

@@ -0,0 +1,7 @@
+<p><a href="http://example.com" title="Say &quot;hi&quot;">Inline</a></p>
+
+<p><a href="http://example.com" title="It's here">Single</a></p>
+
+<p><a href="http://example.com" title="Say &quot;hi&quot;">Reference</a></p>
+
+<p><img src="a.png" alt="Image" title="A &quot;quoted&quot; title" /></p>

test/tm-cases/link_title_escaped_quotes.text

@@ -0,0 +1,9 @@
+[Inline](http://example.com "Say \"hi\"")
+
+[Single](http://example.com 'It\'s here')
+
+[Reference][ref]
+
+![Image](a.png "A \"quoted\" title")
+
+[ref]: http://example.com "Say \"hi\""