--- a/src/aircraft_cmd.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/aircraft_cmd.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -493,7 +493,7 @@
 		DoDeleteAircraft(v);
 	}
 
-	return CommandCost(-(int32)v->value);
+	return CommandCost(-v->value);
 }
 
 /** Start/Stop an aircraft.

--- a/src/clear_cmd.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/clear_cmd.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -446,7 +446,7 @@
 
 static CommandCost ClearTile_Clear(TileIndex tile, byte flags)
 {
-	static const int32* clear_price_table[] = {
+	static const Money* clear_price_table[] = {
 		&_price.clear_1,
 		&_price.purchase_land,
 		&_price.clear_2,

--- a/src/command.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/command.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -602,7 +602,7 @@
 	return *this;
 }
 
-CommandCost CommandCost::AddCost(int32 cost)
+CommandCost CommandCost::AddCost(Money cost)
 {
 	this->cost += cost;
 	return *this;
@@ -614,7 +614,7 @@
 	return *this;
 }
 
-int32 CommandCost::GetCost() const
+Money CommandCost::GetCost() const
 {
 	return this->cost;
 }

--- a/src/economy.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/economy.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -57,10 +57,11 @@
 
 int _score_part[MAX_PLAYERS][SCORE_END];
 
-int64 CalculateCompanyValue(const Player* p)
+Money CalculateCompanyValue(const Player* p)
 {
 	PlayerID owner = p->index;
-	int64 value;
+	/* Do a little nasty by using CommandCost, so we can use the "overflow" protection of CommandCost */
+	CommandCost value;
 
 	{
 		Station *st;
@@ -70,7 +71,7 @@
 			if (st->owner == owner) num += CountBitsSet(st->facilities);
 		}
 
-		value = num * _price.station_value * 25;
+		value.AddCost(num * _price.station_value * 25);
 	}
 
 	{
@@ -83,14 +84,16 @@
 					v->type == VEH_ROAD ||
 					(v->type == VEH_AIRCRAFT && IsNormalAircraft(v)) ||
 					v->type == VEH_SHIP) {
-				value += v->value * 3 >> 1;
+				value.AddCost(v->value * 3 >> 1);
 			}
 		}
 	}
 
-	value += p->player_money - p->current_loan; // add real money value
+	/* Add real money value */
+	value.AddCost(-p->current_loan);
+	value.AddCost(p->player_money);
 
-	return max(value, 1LL);
+	return max(value.GetCost(), 1);
 }
 
 /** if update is set to true, the economy is updated with this score
@@ -148,16 +151,12 @@
 
 /* Generate statistics depending on recent income statistics */
 	{
-		const PlayerEconomyEntry* pee;
-		int numec;
-		int32 min_income;
-		int32 max_income;
+		int numec = min(p->num_valid_stat_ent, 12);
+		if (numec != 0) {
+			const PlayerEconomyEntry *pee = p->old_economy;
+			Money min_income = pee->income + pee->expenses;
+			Money max_income = pee->income + pee->expenses;
 
-		numec = min(p->num_valid_stat_ent, 12);
-		if (numec != 0) {
-			min_income = 0x7FFFFFFF;
-			max_income = 0;
-			pee = p->old_economy;
 			do {
 				min_income = min(min_income, pee->income + pee->expenses);
 				max_income = max(max_income, pee->income + pee->expenses);
@@ -658,11 +657,17 @@
 	InvalidateWindow(WC_COMPANY_LEAGUE, 0);
 }
 
-static void AddSingleInflation(int32 *value, uint16 *frac, int32 amt)
+static void AddSingleInflation(Money *value, uint16 *frac, int32 amt)
 {
-	int64 tmp = (int64)*value * amt + *frac;
-	*frac   = GB(tmp, 0, 16);
-	*value += tmp >> 16;
+	/* Is it safe to add inflation ? */
+	if ((MAX_UVALUE(Money) / 2 / amt) > (*value + *frac + 1)) {
+		*value = MAX_UVALUE(Money);
+		*frac = 0;
+	} else {
+		int64 tmp = (int64)*value * amt + *frac;
+		*frac   = GB(tmp, 0, 16);
+		*value += tmp >> 16;
+	}
 }
 
 static void AddInflation()
@@ -672,10 +677,10 @@
 	 * 12 -> months per year
 	 * This is only a good approxiamtion for small values
 	 */
-	int32 inf = _economy.infl_amount * 54;
+	Money inf = _economy.infl_amount * 54;
 
 	for (uint i = 0; i != NUM_PRICES; i++) {
-		AddSingleInflation((int32*)&_price + i, _price_frac + i, inf);
+		AddSingleInflation((Money*)&_price + i, _price_frac + i, inf);
 	}
 
 	_economy.max_loan_unround += BIGMULUS(_economy.max_loan_unround, inf, 16);
@@ -686,7 +691,7 @@
 	inf = _economy.infl_amount_pr * 54;
 	for (CargoID i = 0; i < NUM_CARGO; i++) {
 		AddSingleInflation(
-			(int32*)_cargo_payment_rates + i,
+			(Money*)_cargo_payment_rates + i,
 			_cargo_payment_rates_frac + i,
 			inf
 		);
@@ -709,7 +714,7 @@
 		_current_player = p->index;
 		SET_EXPENSES_TYPE(EXPENSES_LOAN_INT);
 
-		SubtractMoneyFromPlayer(CommandCost(BIGMULUS(p->current_loan, interest, 16)));
+		SubtractMoneyFromPlayer(CommandCost((Money)BIGMULUS(p->current_loan, interest, 16)));
 
 		SET_EXPENSES_TYPE(EXPENSES_OTHER);
 		SubtractMoneyFromPlayer(_price.station_value >> 2);
@@ -739,7 +744,7 @@
 	2,
 };
 
-static const int32 _price_base[NUM_PRICES] = {
+static const Money _price_base[NUM_PRICES] = {
 	    100, ///< station_value
 	    100, ///< build_rail
 	     95, ///< build_road
@@ -822,10 +827,10 @@
 {
 	int i;
 
-	assert(sizeof(_price) == NUM_PRICES * sizeof(int32));
+	assert(sizeof(_price) == NUM_PRICES * sizeof(Money));
 
 	for (i = 0; i != NUM_PRICES; i++) {
-		int32 price = _price_base[i];
+		Money price = _price_base[i];
 		if (_price_category[i] != 0) {
 			uint mod = _price_category[i] == 1 ? _opt.diff.vehicle_costs : _opt.diff.construction_cost;
 			if (mod < 1) {
@@ -839,7 +844,7 @@
 		} else {
 			price >>= 8 - price_base_multiplier[i];
 		}
-		((int32*)&_price)[i] = price;
+		((Money*)&_price)[i] = price;
 		_price_frac[i] = 0;
 	}
 
@@ -1368,14 +1373,14 @@
 {
 	int result = 0;
 
-	int profit = 0;
-	int total_veh_profit = 0;         // accumulates the profit across the vehicle chain (used by trains)
-	int32 route_profit = 0;           // the grand total amount for the route. A-D of transfer chain A-B-C-D
-	int virtual_profit = 0;           // virtual profit of one vehicle element for feeder systems
-	int virtual_profit_total = 0;     // virtual profit for entire vehicle chain
-	int total_cargo_feeder_share = 0; // the feeder cash amount for the goods being loaded/unloaded in this load step
+	Money profit = 0;
+	Money total_veh_profit = 0;         // accumulates the profit across the vehicle chain (used by trains)
+	Money route_profit = 0;             // the grand total amount for the route. A-D of transfer chain A-B-C-D
+	Money virtual_profit = 0;           // virtual profit of one vehicle element for feeder systems
+	Money virtual_profit_total = 0;     // virtual profit for entire vehicle chain
+	Money total_cargo_feeder_share = 0; // the feeder cash amount for the goods being loaded/unloaded in this load step
 
-	int all_vehicles_cargo_feeder_share = front_v->cargo_feeder_share; // used to hold transfer value of complete vehicle chain - used by trains
+	Money all_vehicles_cargo_feeder_share = front_v->cargo_feeder_share; // used to hold transfer value of complete vehicle chain - used by trains
 
 	StationID last_visited = front_v->last_station_visited;
 	Station *st = GetStation(last_visited);
@@ -1766,7 +1771,7 @@
 {
 	Player *owner;
 	int i;
-	int64 value;
+	Money value;
 
 	SetDParam(0, p->name_1);
 	SetDParam(1, p->name_2);
@@ -1784,13 +1789,15 @@
 	}
 
 	value = CalculateCompanyValue(p) >> 2;
+	PlayerID old_player = _current_player;
 	for (i = 0; i != 4; i++) {
 		if (p->share_owners[i] != PLAYER_SPECTATOR) {
-			owner = GetPlayer(p->share_owners[i]);
-			owner->player_money += value;
-			owner->yearly_expenses[0][EXPENSES_OTHER] += value;
+			SET_EXPENSES_TYPE(EXPENSES_OTHER);
+			_current_player = p->share_owners[i];
+			SubtractMoneyFromPlayer(CommandCost(-value));
 		}
 	}
+	_current_player = old_player;
 
 	p->is_active = false;
 
@@ -1855,7 +1862,7 @@
 CommandCost CmdSellShareInCompany(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
 	Player *p;
-	int64 cost;
+	Money cost;
 
 	/* Check if buying shares is allowed (protection against modified clients */
 	if (!IsValidPlayer((PlayerID)p1) || !_patches.allow_shares) return CMD_ERROR;
@@ -1876,7 +1883,7 @@
 		*b = PLAYER_SPECTATOR;
 		InvalidateWindow(WC_COMPANY, p1);
 	}
-	return CommandCost((int32)cost);
+	return CommandCost(cost);
 }
 
 /** Buy up another company.

--- a/src/main_gui.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/main_gui.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -92,7 +92,7 @@
 #ifdef ENABLE_NETWORK
 	case 3: { // Give money, you can only give money in excess of loan
 		const Player *p = GetPlayer(_current_player);
-		int32 money = min(p->player_money - p->current_loan, atoi(str) / _currency->rate);
+		Money money = min(p->player_money - p->current_loan, atoi(str) / _currency->rate);
 
 		money = clamp(money, 0, 20000000); // Clamp between 20 million and 0
 

--- a/src/misc_cmd.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/misc_cmd.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -133,7 +133,7 @@
 		return_cmd_error(STR_702B_MAXIMUM_PERMITTED_LOAN);
 	}
 
-	int32 loan;
+	Money loan;
 	switch (p2) {
 		default: return CMD_ERROR; // Invalid method
 		case 0: // Take some extra loan
@@ -289,7 +289,7 @@
 	if (_networking) return CMD_ERROR;
 #endif
 	SET_EXPENSES_TYPE(EXPENSES_OTHER);
-	return CommandCost(-(int32)p1);
+	return CommandCost(-(Money)p1);
 }
 
 /** Transfer funds (money) from one player to another.
@@ -304,7 +304,7 @@
 CommandCost CmdGiveMoney(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
 	const Player *p = GetPlayer(_current_player);
-	CommandCost amount(min((int32)p1, 20000000));
+	CommandCost amount((Money)min(p1, 20000000LL));
 
 	SET_EXPENSES_TYPE(EXPENSES_OTHER);
 

--- a/src/misc_gui.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/misc_gui.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -89,7 +89,7 @@
 	Player *p;
 	Window *w;
 	Town *t;
-	int64 old_money;
+	Money old_money;
 	CommandCost costclear;
 	AcceptedCargo ac;
 	TileDesc td;

--- a/src/openttd.h	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/openttd.h	Mon Jun 18 21:44:47 2007 +0000
@@ -69,6 +69,7 @@
 typedef uint16 GroupID;
 typedef uint16 EngineRenewID;
 typedef uint16 DestinationID;
+typedef int32 Money;
 
 /* DestinationID must be at least as large as every these below, because it can
  * be any of them
@@ -226,53 +227,53 @@
 };
 
 struct Prices {
-	int32 station_value;
-	int32 build_rail;
-	int32 build_road;
-	int32 build_signals;
-	int32 build_bridge;
-	int32 build_train_depot;
-	int32 build_road_depot;
-	int32 build_ship_depot;
-	int32 build_tunnel;
-	int32 train_station_track;
-	int32 train_station_length;
-	int32 build_airport;
-	int32 build_bus_station;
-	int32 build_truck_station;
-	int32 build_dock;
-	int32 build_railvehicle;
-	int32 build_railwagon;
-	int32 aircraft_base;
-	int32 roadveh_base;
-	int32 ship_base;
-	int32 build_trees;
-	int32 terraform;
-	int32 clear_1;
-	int32 purchase_land;
-	int32 clear_2;
-	int32 clear_3;
-	int32 remove_trees;
-	int32 remove_rail;
-	int32 remove_signals;
-	int32 clear_bridge;
-	int32 remove_train_depot;
-	int32 remove_road_depot;
-	int32 remove_ship_depot;
-	int32 clear_tunnel;
-	int32 clear_water;
-	int32 remove_rail_station;
-	int32 remove_airport;
-	int32 remove_bus_station;
-	int32 remove_truck_station;
-	int32 remove_dock;
-	int32 remove_house;
-	int32 remove_road;
-	int32 running_rail[3];
-	int32 aircraft_running;
-	int32 roadveh_running;
-	int32 ship_running;
-	int32 build_industry;
+	Money station_value;
+	Money build_rail;
+	Money build_road;
+	Money build_signals;
+	Money build_bridge;
+	Money build_train_depot;
+	Money build_road_depot;
+	Money build_ship_depot;
+	Money build_tunnel;
+	Money train_station_track;
+	Money train_station_length;
+	Money build_airport;
+	Money build_bus_station;
+	Money build_truck_station;
+	Money build_dock;
+	Money build_railvehicle;
+	Money build_railwagon;
+	Money aircraft_base;
+	Money roadveh_base;
+	Money ship_base;
+	Money build_trees;
+	Money terraform;
+	Money clear_1;
+	Money purchase_land;
+	Money clear_2;
+	Money clear_3;
+	Money remove_trees;
+	Money remove_rail;
+	Money remove_signals;
+	Money clear_bridge;
+	Money remove_train_depot;
+	Money remove_road_depot;
+	Money remove_ship_depot;
+	Money clear_tunnel;
+	Money clear_water;
+	Money remove_rail_station;
+	Money remove_airport;
+	Money remove_bus_station;
+	Money remove_truck_station;
+	Money remove_dock;
+	Money remove_house;
+	Money remove_road;
+	Money running_rail[3];
+	Money aircraft_running;
+	Money roadveh_running;
+	Money ship_running;
+	Money build_industry;
 };
 
 #define GAME_DIFFICULTY_NUM 18
@@ -365,7 +366,7 @@
  * a possible error message/state together.
  */
 class CommandCost {
-	int32 cost;       ///< The cost of this action
+	Money cost;       ///< The cost of this action
 	StringID message; ///< Warning message for when success is unset
 	bool success;     ///< Whether the comment went fine up to this moment
 
@@ -384,7 +385,7 @@
 	 * Creates a command return value with the given start cost
 	 * @param cst the initial cost of this command
 	 */
-	CommandCost(int32 cst) : cost(cst), message(INVALID_STRING_ID), success(true) {}
+	CommandCost(Money cst) : cost(cst), message(INVALID_STRING_ID), success(true) {}
 	/** "Hack" to make everything compile nicely, not needed when cost is int64 */
 	CommandCost(uint cst) : cost(cst), message(INVALID_STRING_ID), success(true) {}
 
@@ -401,7 +402,7 @@
 	 * @param cost the cost to add
 	 * @return this class.
 	 */
-	CommandCost AddCost(int32 cost);
+	CommandCost AddCost(Money cost);
 
 	/**
 	 * Multiplies the cost of the command by the given factor.
@@ -414,7 +415,7 @@
 	 * The costs as made up to this moment
 	 * @return the costs
 	 */
-	int32 GetCost() const;
+	Money GetCost() const;
 
 	/**
 	 * Sets the global error message *if* this class has one.

--- a/src/player.h	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/player.h	Mon Jun 18 21:44:47 2007 +0000
@@ -12,8 +12,8 @@
 #include "livery.h"
 
 struct PlayerEconomyEntry {
-	int32 income;
-	int32 expenses;
+	Money income;
+	Money expenses;
 	int32 delivered_cargo;
 	int32 performance_history; ///< player score (scale 0-1000)
 	int64 company_value;
@@ -166,8 +166,8 @@
 
 	PlayerFace face;
 
-	int32 current_loan;
 	int64 player_money;
+	Money current_loan;
 
 	byte player_color;
 	Livery livery[LS_END];
@@ -190,7 +190,7 @@
 	byte quarters_of_bankrupcy;
 	byte bankrupt_asked; ///< which players were asked about buying it?
 	int16 bankrupt_timeout;
-	int32 bankrupt_value;
+	Money bankrupt_value;
 
 	bool is_active;
 	bool is_ai;
@@ -212,7 +212,7 @@
 
 void ChangeOwnershipOfPlayerItems(PlayerID old_player, PlayerID new_player);
 void GetNameOfOwner(Owner owner, TileIndex tile);
-int64 CalculateCompanyValue(const Player* p);
+Money CalculateCompanyValue(const Player* p);
 void InvalidatePlayerWindows(const Player* p);
 void SetLocalPlayer(PlayerID new_player);
 #define FOR_ALL_PLAYERS(p) for (p = _players; p != endof(_players); p++)

--- a/src/players.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/players.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -188,22 +188,30 @@
 
 static void SubtractMoneyFromAnyPlayer(Player *p, CommandCost cost)
 {
-	p->player_money -= cost.GetCost();
+	CommandCost tmp((int32)p->player_money);
+	tmp.AddCost(-cost.GetCost());
+	p->player_money = tmp.GetCost();
 
-	p->yearly_expenses[0][_yearly_expenses_type] += cost.GetCost();
+	tmp = CommandCost((int32)p->yearly_expenses[0][_yearly_expenses_type]);
+	tmp.AddCost(cost);
+	p->yearly_expenses[0][_yearly_expenses_type] = tmp.GetCost();
 
 	if (HASBIT(1 << EXPENSES_TRAIN_INC    |
 	           1 << EXPENSES_ROADVEH_INC  |
 	           1 << EXPENSES_AIRCRAFT_INC |
 	           1 << EXPENSES_SHIP_INC, _yearly_expenses_type)) {
-		p->cur_economy.income -= cost.GetCost();
+		tmp = CommandCost(p->cur_economy.income);
+		tmp.AddCost(-cost.GetCost());
+		p->cur_economy.income = tmp.GetCost();
 	} else if (HASBIT(1 << EXPENSES_TRAIN_RUN    |
 	                  1 << EXPENSES_ROADVEH_RUN  |
 	                  1 << EXPENSES_AIRCRAFT_RUN |
 	                  1 << EXPENSES_SHIP_RUN     |
 	                  1 << EXPENSES_PROPERTY     |
 	                  1 << EXPENSES_LOAN_INT, _yearly_expenses_type)) {
-		p->cur_economy.expenses -= cost.GetCost();
+		tmp = CommandCost(p->cur_economy.expenses);
+		tmp.AddCost(-cost.GetCost());
+		p->cur_economy.expenses = tmp.GetCost();
 	}
 
 	InvalidatePlayerWindows(p);
@@ -220,7 +228,7 @@
 {
 	Player *p = GetPlayer(player);
 	byte m = p->player_money_fraction;
-	int32 cost = cst.GetCost();
+	Money cost = cst.GetCost();
 
 	p->player_money_fraction = m - (byte)cost;
 	cost >>= 8;

--- a/src/roadveh_cmd.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/roadveh_cmd.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -373,7 +373,7 @@
 		DeleteVehicle(v);
 	}
 
-	return CommandCost(-(int32)v->value);
+	return CommandCost(-v->value);
 }
 
 struct RoadFindDepotData {

--- a/src/ship_cmd.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/ship_cmd.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -929,7 +929,7 @@
 		DeleteVehicle(v);
 	}
 
-	return CommandCost(-(int32)v->value);
+	return CommandCost(-v->value);
 }
 
 /** Start/Stop a ship.

--- a/src/station.h	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/station.h	Mon Jun 18 21:44:47 2007 +0000
@@ -39,7 +39,7 @@
 	byte enroute_time;
 	byte last_speed;
 	byte last_age;
-	int32 feeder_profit;
+	Money feeder_profit;
 };
 
 /** A Stop for a Road Vehicle */

--- a/src/train_cmd.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/train_cmd.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -3353,9 +3353,9 @@
 	InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
 }
 
-int32 GetTrainRunningCost(const Vehicle *v)
+Money GetTrainRunningCost(const Vehicle *v)
 {
-	int32 cost = 0;
+	Money cost = 0;
 
 	do {
 		const RailVehicleInfo *rvi = RailVehInfo(v->engine_type);

--- a/src/unmovable_cmd.cpp	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/unmovable_cmd.cpp	Mon Jun 18 21:44:47 2007 +0000
@@ -49,7 +49,7 @@
 	}
 
 	/* cost of relocating company is 1% of company value */
-	return CommandCost((int32)(CalculateCompanyValue(p) / 100));
+	return CommandCost(CalculateCompanyValue(p) / 100);
 }
 
 void UpdateCompanyHQ(Player *p, uint score)

--- a/src/vehicle.h	Mon Jun 18 21:00:14 2007 +0000
+++ b/src/vehicle.h	Mon Jun 18 21:44:47 2007 +0000
@@ -312,11 +312,11 @@
 	uint16 cargo_paid_for;      // How much of the cargo currently on board has been paid for.
 	byte vehicle_flags;         // Used for gradual loading and other miscellaneous things (@see VehicleFlags enum)
 
-	int32 profit_this_year;
-	int32 profit_last_year;
-	int32 cargo_feeder_share;      ///< value of feeder pickup to be paid for on delivery of cargo
+	Money profit_this_year;
+	Money profit_last_year;
+	Money cargo_feeder_share;      ///< value of feeder pickup to be paid for on delivery of cargo
 	TileIndex cargo_loaded_at_xy;  ///< tile index where feeder cargo was loaded
-	uint32 value;
+	Money value;
 
 	GroupID group_id;              ///< Index of group Pool array
 
@@ -548,7 +548,7 @@
 
 void TrainConsistChanged(Vehicle *v);
 void TrainPowerChanged(Vehicle *v);
-int32 GetTrainRunningCost(const Vehicle *v);
+Money GetTrainRunningCost(const Vehicle *v);
 
 int CheckTrainStoppedInDepot(const Vehicle *v);