Freeciv

Seen when investigating https://osdn.net/projects/freeciv/ticket/78170 reported by bard:

unit_focus_advance() expects current focus to be untouched when the function is entered, to figure out if it's time for automatic turn done. control_unit_killed() removes the dying unit from the focus before unit_focus_advance() gets called, so unit_focus_advance() does not detect that dying unit should trigger the turn done.