Editing Activity from an activity search list loses the "with" contact

I replicated this issue on http://drupal.demo.civicrm.org
Here are the steps that I did:
1) Searched for a group of people
2) associated a separate "phone call" activity with each contact in the group.
3) Used activity search to pull up a list of "phone call" activities.
4) selected edit for one of the activities that had a "with" person
5) found that the "with" person was not displayed.

Conversely, if one edits the activity of a contact from the contact's "View Contact" screen, the "with" field is properly populated.