GAWLP > empty search field does not pass Subject & SubjectParent

This page is configured for search only, with subject and subjectParent features set and no validation: http://current.dev.curriki.org/xwiki/bin/view/AdWordsJump/TestPage1

When a user enters a search term and submits, the subject & subjectParent fields are passed to Advanced Search.

When a user does not enter a search term and hits submit, the fields are not passed, but they should be.

Refer also to this page, configured for both search and email: http://current.dev.curriki.org/xwiki/bin/view/AdWordsJump/TestPage4