New Event Registration (back-office) : Custom field data missing on participant receipts when custom group is assigned "by event name"

New event registration (back-office) - If you have a custom data group where Used For = Participants (by Event Name) - and you register someone for that event and send a receipt - the custom group values are NOT populated in the $customGroup array passed to ReceiptMessage.tpl (and hence the values are not shown on the receipt email).

It looks like the problem is in the CRM_Core_BAO_UFGroup::getValues call on line 1138 in CRM_Event_Form_Participant.php

If you create a custom data group with Used For = Participants - and then register via backoffice - the $customGroup array is properly populated and the data shows up in the receipt.