define format at one place

[civicrm-core.git] / CRM / Contact / BAO / GroupContact.php

diff --git a/CRM/Contact/BAO/GroupContact.php b/CRM/Contact/BAO/GroupContact.php
index dcbafcdfe94819babb2dd274a8e6e51e6633a936..ddae644d62858ca1693dd3fef3772239861673b4 100644 (file)
--- a/CRM/Contact/BAO/GroupContact.php
+++ b/CRM/Contact/BAO/GroupContact.php
@@ -691,7 +691,7 @@ AND    contact_id IN ( $contactStr )
       $presentIDs = [];
       $dao = CRM_Core_DAO::executeQuery($sql, $params);
       if ($dao->fetch()) {
-        $presentIDs = explode(',', $dao->contactStr);
+        $presentIDs = explode(',', ($dao->contactStr ?? ''));
         $presentIDs = array_flip($presentIDs);
       }