WP adding tags no matter what the settings are

[retrib]

Hi guys! I've got latest WP installation (3.0.3) and found strange bug in posts parser.

Create article with following HTML:

<div class="wassup"><a href="#">WP IZ ASSUM</a></div>

Browser will get:

<div class="wassup"><a href="#">WP IZ ASSUM</a></div>

All seems to be fine! Now get rid of unnecessary div.

Create article with following HTML:

<a href="#">WP IZ ASSUM</a>

Browser will get:

<p><a href="#">WP IZ ASSUM</a></p>

Dunno why there is extra <p> but who cares. All seems to be OK.

Create article with following HTML:

<figure><a href="#">WP IZ ASSUM</a>
</figure>

Browser will get:

<figure><a href="#">WP IZ ASSUM</a><br />
</figure>

Now isn't that cool? But check what is even cooler!

Create article with following HTML:

<figure><a href="#">WP IZ ASSUM</a>
<figcaption>NO IT'S BUGGY AS HELL</figcaption>
</figure>

Browser will get:

<figure><a href="#">WP IZ ASSUM</a></p>
<figcaption>NO IT’S BUGGY AS HELL</figcaption>
</figure>

Wow! Say hello to invalid markup and rendering problems! Auto-closing of tags turned off. No matter of the settings I still get this nice messed up html. WYSIWYG turned off also.

The problem is that wpautop() doesn't know how to treat the new HTML5 tags yet.