hotline_#16652_search_with_bib_filter dont display zone if empty

library/Class/Bib.php

@@ -114,9 +114,11 @@ class BibLoader extends Storm_Model_Loader {
 		$selected_zones = [];
 		$select_bibs_not_in_zone = [];
 		foreach($bibs_by_zones as $id => $bibs) {
-			if(!$ids)
+			if(!$ids || !$bibs)
 				continue;
+
 			$bibs_ids = [];
+
 			foreach($bibs as $bib)
 				$bibs_ids[] = $bib->getId();