check content_object is valid before carrying on

fulcrm_shoppingcart_transaction_item.tpl.php

@@ -1,5 +1,5 @@
 <tr>
-    <td><?php print nl2br( check_plain( $item[ 'name' ] ) ); if ( array_key_exists( 'content_object', $item ) ) {
+    <td><?php print nl2br( check_plain( $item[ 'name' ] ) ); if ( array_key_exists( 'content_object', $item ) && is_array( $item[ 'content_object' ] ) && array_key_exists( 'url', $item[ 'content_object' ] ) ) {
         if ( fulcrm_apiv2_url_is_type( $item[ 'content_object' ][ 'url' ], 'eventbooking' ) ) {
             if ( $item[ 'content_object' ][ 'attended' ] ) {
                 print '<br /><strong>Thank you for coming to the event!</strong>';