Incomplete test in search_view function

Hello,

I found a mistake on the search module.

My aim is to have one form on the result area to do some actions.
But when I submit my form, search_view function broke the treatment to keep the search auery URL clean.

In fact search_view test if 'form_id' post variable is set. So when I submit my form, the is a 'form_id' too.

I think, the test must be re-written to ckeck the form_id value.

So patch should be on line 16 :
if (!(isset($_POST['form_id']) && $_POST['form_id'] == 'search_form')) {