Fixed bug -- warning caused by passing empty string instead of empty array.

module/VuFind/src/VuFind/Controller/Plugin/Favorites.php

@@ -85,7 +85,7 @@ class Favorites extends AbstractPlugin
             // Add the information to the user's account:
             $tags = isset($params['mytags'])
                 ? Tags::parse(trim($params['mytags']))
-                : '';
+                : array();
             $user->saveResource($resource, $list, $tags, '', false);
         }
     }

module/VuFind/src/VuFind/RecordDriver/AbstractBase.php

@@ -180,7 +180,8 @@ abstract class AbstractBase
         // Add the information to the user's account:
         $user->saveResource(
             $resource, $list,
-            isset($params['mytags']) ? Tags::parse(trim($params['mytags'])) : '',
+            isset($params['mytags'])
+                ? Tags::parse(trim($params['mytags'])) : array(),
             isset($params['notes']) ? $params['notes'] : ''
         );
     }