[Freeciv-Dev] (PR#4345) pcity->occupied not properly updated

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

Based on all the different bug reports submitted on this problem (now
all merged into one ticket), I suspect there are other places where the
client's 'occupied' field is not updated & resent as necessary. 
However, the old bug reports aren't too useful because of all the fixes
done since then.

So, any problems still found in CVS on this topic should be reported
again.  Try to make it as easy as possible for me to reproduce. 
Remember that old savegames may give invalid 'occupied' data, since this
information wasn't put into the savegame until recently.


Also anyone who will do an audit (code-wise or game-rules-wise) is
welcome.  Currently we update & send out the occupied information:

- When a *short* city packet just happens to be sent out anyway.
- When a unit moves into or out of the city.

I believe the full city packet should also send the occupied field, just
to be safe (the code assumes a short city packet is unnecessary if a
full packet is sent).  But it may still be necessary to do checks at
other times; e.g. after combat, after units are built, etc.

jason