Filters disappear if no records found

The filter box is not displayed on the results page if the filter condition fails to find any hits resulting in the inability to refine the filter condition to turn an unsuccessful search into a successful one.

**How to reproduce the problem and/or test the patch::**__
Set up menu item to display weblinks
activate weblinks menu item
page displays filter box above the list of weblinks.
Enter a filter term and hit the enter key to activate the search. If the filter term selects a group of records they are displayed with the filter box containing the search term, exactly as expected. If the filter term finds no hits, then not only is the list empty but the filter box with the unsuccessful search term is also missing so that there is no opportunity to refine the search.

http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=33479&start=0