Update on pull -u when heads were closed (fixes issue666)....
Update on pull -u when heads were closed (fixes issue666).
Patch written by Benoit Boissinot.
This should probably be improved in the future to handle long-living
branches, as joining two "other" heads will switch to that new head.
But this is not a new problem, as adding to the "other" head would have
switched to that new head, too.
