[issue34480] _markupbase.py fails with UnboundLocalError on invalid keyword in marked section

Leonard Richardson added the comment: I'm the maintainer of Beautiful Soup. I learned about this issue when one of my users filed a bug for it against Beautiful Soup (https://bugs.launchpad.net/beautifulsoup/+bug/1883264). BeautifulSoupHTMLParser (my subclass of html.parser.HTMLP

[issue37747] _markupbase.py fails with TypeError on invalid keyword in marked section

Leonard Richardson added the comment: This was also recently filed as a bug against Beautiful Soup, a package I maintain, using Python 3.8. (https://bugs.launchpad.net/beautifulsoup/+bug/1883104) The attached script reproduces the problem without using external packages. -- nosy