Auto-closing tags in template

I’m trying to figure out what is auto completing open tags in my template files. For example something as simple as,

<?php get_header(); ?>
<a href="#"> <!-- purposefully left open -->
<?php get_footer(); ?>

gets turned into

<a href="#"></a><!-- now has a closing tag -->

Ultimately, I’m developing an HTML5 theme and want to wrap the <article> in an href tag which is now okay to do. The problem is WordPress is closing my href immediately.

I’m hoping someone just knows the filter I can remove to disable the “auto-complete.”