warning: array_filter()

Sometimes the $display->display_options is empty. Then the array_filter causes a warning.
Possible solution:

Index: sites/all/modules/contributions/ecommerce/ec_common/ec_common.module
===================================================================
--- sites/all/modules/contributions/ecommerce/ec_common/ec_common.module	(revision)
+++ sites/all/modules/contributions/ecommerce/ec_common/ec_common.module	(working copy)
@@ -210,8 +210,8 @@
 
 function ec_common_form_views_exposed_form_alter(&$form, &$form_state) {
   $display =& $form_state['display'];
-  
-  if ($filters = array_filter($display->display_options['filters'], '_ec_filter_exposed_filter')) {
+
+  if (is_array($display->display_options['filters']) && $filters = array_filter($display->display_options['filters'], '_ec_filter_exposed_filter')) {
     foreach ($filters as $id => $filter) {
       $filters+= array(
         'fields' => array(),