CiviMail ignores child groups when getting recipients

Encountered on 3.1.3, replicated on demo: http://drupal.demo.civicrm.org/civicrm/mailing/report?mid=18&reset=1 (July 7th, 2010 8:12 AM)

1. Create a mailing group, add a member.
2. Create a child mailing group of the above, add 2 members.
3. Create & send a mailing to the parent group.

While composing the mailing, the recipient count showed as 1, should have been 3. After sending the mailing, report shows 1 recipient.

4. Create & send a mailing to the child group.

While composing the mailing, the recipient count correctly showed as 2 and after sending the mailing, report correctly shows 2 recipients.

Looking at CRM_Mailing_BAO_Mailing::getRecipients, the queries use civicrm_group_contact to get group members and do not check child groups.

See http://forum.civicrm.org/index.php?topic=13478.0

Dave J