Case activities have incorrect cid in View link on Full Text Search

If your search on Activities in Full Text Search returns a case activity, the link to "View" the activity record has the "source" contact_id rather than the case client contact_id in the URL.

Example:
Case client is cid=41, but View link in full text search is:
http://localhost/dgg/d6/civicrm/case/activity/view?reset=1&aid=553&cid=102&caseID=1&context=fulltext&contextQFKey=280542c6738aa97e717f3de2fc16285b_8052

The resulting Activity View screen is attached as screenshot.

To recreate:

• configure sample case .xml and .mysql and enable CiviCase
• create a case and edit one activity to put in a known subject
• search on the subject string in Full Text search
• click View on the found record.