I have been working on http://drupal.org/node/1269734 and have found that one form in Core doesn't seem to get passed through theme_form.

search_block_form has a theme hook set in search_theme().  The hook sets the template to search-block-form.tpl.php, and sets the render element as 'form'.

This appears to create the following markup:

1. The <form> wrapper (which does not appear to be themed with theme_form().

2. The contents from search-block-form.tpl.php

3. The children of the form, printed in search-block-form.tpl.php, from the $search_form variable, defined in template_preprocess_search_block_form()

Is it right to expect that the form element is not passed through theme_form() when it is rendered in this way, or is this a bug?

Thanks,