(svn r16694) -Fix [FS#2995] (rgradual loading, rnewindustries): only pay for whatever has been actually unloaded and perform the payment when unloading has finished. This fixes, amongst others:

* cheating by starting to unload and after getting paid rushing to the depot to get sold (or unloading, loading and getting paid again for the remainder)
 * cargo being dropped onto a station at the moment a stockpiling industry doesn't accept it anymore
 * industries getting cargo that has not been unloaded yet and subsequently dumping it back on the station in one go
Note: you will now get paid after the unloading has finished, so you'll have to wait a bit longer for 'your' money.

src/economy_base.h

@@ -7,19 +7,26 @@
 
 #include "cargopacket.h"
 
+/** Type of pool to store cargo payments in. */
+typedef Pool<CargoPayment, CargoPaymentID, 512, 64000> CargoPaymentPool;
+/** The actual pool to store cargo payments in. */
+extern CargoPaymentPool _cargo_payment_pool;
+
 /**
  * Helper class to perform the cargo payment.
  */
-struct CargoPayment {
+struct CargoPayment : CargoPaymentPool::PoolItem<&_cargo_payment_pool> {
 	Vehicle *front;      ///< The front vehicle to do the payment of
 	Money route_profit;  ///< The amount of money to add/remove from the bank account
 	Money visual_profit; ///< The visual profit to show
 
+	/* Unsaved variables */
 	Company *owner;            ///< The owner of the vehicle
 	StationID current_station; ///< The current station
 	CargoID ct;                ///< The currently handled cargo type
 
 	/** Constructor for pool saveload */
+	CargoPayment() {}
 	CargoPayment(Vehicle *front);
 	~CargoPayment();
 
@@ -33,4 +40,7 @@ struct CargoPayment {
 	void SetCargo(CargoID ct) { this->ct = ct; }
 };
 
+#define FOR_ALL_CARGO_PAYMENTS_FROM(var, start) FOR_ALL_ITEMS_FROM(CargoPayment, cargo_payment_index, var, start)
+#define FOR_ALL_CARGO_PAYMENTS(var) FOR_ALL_CARGO_PAYMENTS_FROM(var, 0)
+
 #endif /* ECONOMY_BASE_H */