Re: [Freeciv-Dev] Bug in savegame loading?

[David Pfitzner <dwp@xxxxxxxxxxxxxx>]

Trent Piepho wrote:

> On Thu, 11 Mar 1999, David Pfitzner wrote:

> > Possibly compare the old value (in the unit struct) to 
> > a newly calculated value, and re-send a PACKET_INCITE_COST
> > if different (to popup a new confirmation with the new
> > cost).
> 
> That would be annoying.  Each time a player spends some money, the bribe cost
> changes.  Imagine a lagged player trying to bribe a unit when the enemy keeps
> buying things for his cities.  You might have to try 5 or 6 times.  

Well, you could have the server only send a new PACKET_INCITE_COST
if the cost has gone up.  (If it has gone down, the player
already agreed to a higher cost, so should be happy with
a discount.)  But then there could still be a problem for
a lagged player trying to bribe from someone who kept selling 
things...

> Why not
> just say that the cost is calculated when the player attempts to bribe the
> units or city, and that it is good until the player says yes or no?  

Yeah, I guess that is reasonable.  Its unlikely that you
will get a case where a player waits a long time before
starting to bribe and accepting.  

I guess I'm worried about a hacked client which sends 
PACKET_DIPLOMAT_ACTION:DIPLOMAT_BRIBE without a preceeding
PACKET_INCITE_INQ.  That could then use a bribe cost which 
was calculated many turns previously.  Ok, there are probably 
many ways in which a hacked client can subvert the server,
but it would be nice to fix them where possible.

(You could set the bribe_cost to a flag value at the
start of a turn and complain of a bribe attempt if
the value is still the flag value. (That is, if
PACKET_DIPLOMAT_ACTION:DIPLOMAT_BRIBE before 
PACKET_INCITE_INQ.))

Even stranger things can happen in the (admittedly unlikely)
case that two player both try to bribe the same unit belonging
to a third player.  With different costs when they start to
bribe, and various orders for pressing ok.  Hmm, when a unit
is bribed, does it keep the same id?  (Can't check right now.)
But probably not worth worrying about (as long as there are 
no core dumps etc involved, which I don't think there are here).

> Before I
> added the bit with PACKET_INCITE_INQ the bribe cost was sent to the client
> with every unit update, however the server only calculated it at the beginning
> of the turn.  So if you took the enemy capital, his units wouldn't get any
> cheaper.

Yeah, the current situation is better than before.

I suggest we just delete the unnecessary calls to
unit_bribe_cost(), and for now rely on the client to do
the right thing.  That is, the cost is set at the
time when PACKET_INCITE_INQ is received by the server.

Regards,
-- David