Handle multivalued custom sets during merge

I have noticed that when I merge contacts and there is multiple records of in one set of custom data on the duplicate record only 1 record is added to the original record

I have managed to reproduce this on the Drupal 4.4. demo site as well.

To reproduce this I created a custom data set which allows for multipule records and add a custom test field. I then created 2 contacts http://drupal.demo.civicrm.org/civicrm/contact/view?reset=1&cid=210 http://drupal.demo.civicrm.org/civicrm/contact/view?reset=1&cid=211. I gave both contact records 2 custom field records. I then merged them so that CID 210 was the "duplicate" and 211 was the original. Post merge 211 had 3 records for that custom data set (original 2 + 1 from CID 210)

To reproduce

Create 2 contact records

Edit each contact record so that there are 2 records in the "test multiple custom data" custom data

Merge the 2 contact records - notice that not both of the records from the duplicate record are added