Incorrect commenting in XMLTools plugin

[NN]

<a>
 <b></b>
</a>

Select
Press Ctrl+K you get:

<a>
 <!-- <b></b> -->
</a>

Now select everything, Ctrl+K, you get:

<!-- <a>
 <!-- <b></b> -->
</a> -->

This is an incorrect xml.
The commenting operation must take care of inner comments and change them accordingly.