Merge pull request #682 from magefan/magefan-patch-52

Update Collection.php

Author: magefan

Model/ResourceModel/Post/Collection.php

@@ -369,6 +369,10 @@ public function addArchiveFilter($year, $month)
      */
     public function addSearchFilter($term)
     {
+        if (!$term) {
+            $term = '__EMPTY_SEARCH_VALUE__';
+        }
+
         $tagPostIds = [];
         $connection = $this->getConnection();
         $select = $connection->select()