joomla/joomla-platform — pull request #567 by radiant-tech (2011-11-28 18:36:29+00:00)
Title: JFilterInput does not handle comment tags well.  

See Joomla CMS tracker #26893. This adds a check for comment tags prior to the check for malformed tags. If comment tag has proper open and close, any text or html within the tags is skipped over. If the closing comment tag is missing, any contained html is cleaned and the opening tag is left in place to reduce user confusion (so they can see they had an opening tag but no closing tag).