[wp-hackers] Removing empty HTML tags from the_content

[zanematthew at gmail.com]

I'm not sure if this is built into core or not, but I'm looking for a hook
that will remove empty html tags. My content is coming from the db and may
or may not contain invalid html.

In short I'd like to remove stuff like this <p><a></a></p>.

I've also tried looking over
http://core.trac.wordpress.org/browser/tags/3.4.1/wp-includes/formatting.php