[Freeciv-Dev] (PR#13347) server crash in real_unit_change_homecity

["Benoit Hudson" <bh@xxxxxxxxxxxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=13347 >

I trigger the assertion:
313       assert(unit_owner(punit) == city_owner(new_pcity));

Interestingly, to debug, I tried adding (at the top of the function) the
assertion:
273       assert(unit_owner(punit) == old_owner);

But it didn't fire!

The last message printed before the crash is Player 'Karl' now has AI
skill level 'hard'.  So apparently we've (again) got a bug in civil war.

I can't replicate this from a savegame.  I used the standard autogame
settings, and it crashed about 1850ad, but we've seen before that
Apple/OSX autogames don't match intel/linux autogames.