pref-filters: add some sql checks

modules/pref-filters.php

@@ -61,6 +61,7 @@
 								db_escape_string($line["action_param"])."' AND
 								owner_uid = " . $_SESSION["uid"]);
 
+						if (db_num_rows($tmp_result) != 0) {
 							$fg_color = db_fetch_result($tmp_result, 0, "fg_color");
 							$bg_color = db_fetch_result($tmp_result, 0, "bg_color");
 
@@ -69,6 +70,7 @@
 							$line['action_param'] = $tmp;
 						}
 					}
+				}
 
 				$filter = array();
 				$filter['id'] = 'FILTER:' . $line['id'];