Merge pull request #11437 from civicrm/4.7.29-rc

4.7.29 rc merge to master

diff --cc CRM/Group/Form/Edit.php
index fb6e1e0e6d74f49c228705d2a71e4475320ca3e0,55b9478a0ed132ed7451164110c23b6d9753cd9e..e9635dd90d9fdea0a70edd06273eed9da58a1071
--- 1/CRM/Group/Form/Edit.php
--- 2/CRM/Group/Form/Edit.php
+++ b/CRM/Group/Form/Edit.php
@@@ -378,8 -378,13 +378,13 @@@ WHERE  title = %
          $params['group_organization'] = $this->_groupOrganizationID;
        }
  
+       // CRM-21431 If all group_type are unchecked, the change will not be saved otherwise.
+       if (!isset($params['group_type'])) {
+         $params['group_type'] = array();
+       }
+ 
        $params['is_reserved'] = CRM_Utils_Array::value('is_reserved', $params, FALSE);
 -
 +      $params['is_active'] = CRM_Utils_Array::value('is_active', $params, FALSE);
        $params['custom'] = CRM_Core_BAO_CustomField::postProcess($params,
          $this->_id,
          'Group'