(svn r2365) - Change: [refitting] Make refitting capacities for trains newgrf compatible. Train vehicles can now carry twice as much mail/goods as other cargo, and four times as much passengers.

- Fix: [refitting] The refit window now shows the correct refit options for the entire consist. Only if at least one of the vehicles in the train can be refitted to a certain cargo, it is shown in the list.
 - Fix: [refitting] When refitting to a cargo which is already carried by some vehicles in the consist, the capacities of those vehicles are taken into account when calculating the new capacity of the train in the refit window.

train_cmd.c

@@ -841,13 +841,15 @@ int32 CmdMoveRailVehicle(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 		if (src_head->subtype == TS_Front_Engine)
 			UpdateTrainAcceleration(src_head);
 		InvalidateWindow(WC_VEHICLE_DETAILS, src_head->index);
+		InvalidateWindow(WC_VEHICLE_REFIT, src_head->index);
 
 		if (dst_head) {
 			if (dst_head->subtype == TS_Front_Engine)
 				UpdateTrainAcceleration(dst_head);
 			InvalidateWindow(WC_VEHICLE_DETAILS, dst_head->index);
-			/* Update the refit button */
+			/* Update the refit button and window */
 			InvalidateWindowWidget(WC_VEHICLE_VIEW, dst_head->index, 12);
+			InvalidateWindow(WC_VEHICLE_REFIT, dst_head->index);
 		}
 
 		/* I added this to so that the refit buttons get updated */
@@ -996,6 +998,7 @@ int32 CmdSellRailWagon(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 				/* 5. If the train still exists, update its acceleration, window, etc. */
 				if (first != NULL && first->subtype == TS_Front_Engine) {
 					InvalidateWindow(WC_VEHICLE_DETAILS, first->index);
+					InvalidateWindow(WC_VEHICLE_REFIT, first->index);
 					UpdateTrainAcceleration(first);
 				}
 
@@ -1315,21 +1318,41 @@ int32 CmdRefitRailVehicle(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	cost = 0;
 	num = 0;
 
+	// newgrf stuff can change graphics when refitting
+	if (!(flags & DC_EXEC))
+		InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
+
 	do {
 		/* XXX: We also refit all the attached wagons en-masse if they
 		 * can be refitted. This is how TTDPatch does it.  TODO: Have
 		 * some nice [Refit] button near each wagon. --pasky */
 		if (!CanRefitTo(v, new_cid)) continue;
 
-		if (new_cid != v->cargo_type && v->cargo_cap != 0) {
-			cost += (_price.build_railvehicle >> 8);
-			num += v->cargo_cap;
+		if (v->cargo_cap != 0) {
+			RailVehicleInfo *rvi = RailVehInfo(v->engine_type);
+			uint16 amount = rvi->capacity;
+			CargoID old_cid = rvi->cargo_type;
+
+			/* the capacity depends on the cargo type, a rail vehicle
+			 * can carry twice as much mail/goods as normal cargo,
+			 * and four times as much passengers */
+			(old_cid == CT_PASSENGERS) ||
+			(amount <<= 1, old_cid == CT_MAIL || old_cid == CT_GOODS) ||
+			(amount <<= 1, true);
+			(new_cid == CT_PASSENGERS) ||
+			(amount >>= 1, new_cid == CT_MAIL || new_cid == CT_GOODS) ||
+			(amount >>= 1, true);
+
+			if (new_cid != v->cargo_type)
+				cost += (_price.build_railvehicle >> 8);
+			num += amount;
 			if (flags & DC_EXEC) {
 				//autorefitted train cars wants to keep the cargo
 				//it will be checked if the cargo is valid in CmdReplaceVehicle
 				if (!(SkipStoppedInDepotCheck))
 					v->cargo_count = 0;
 				v->cargo_type = new_cid;
+				v->cargo_cap = amount;
 				InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
 			}
 		}

vehicle_gui.c

@@ -165,9 +165,9 @@ void DrawVehicleProfitButton(Vehicle *v, int x, int y)
 	DrawSprite(SPR_BLOT | ormod, x, y);
 }
 
-/** Draw the list of available refit options.
+/** Draw the list of available refit options for a consist.
  * Draw the list and highlight the selected refit option (if any)
- * @param *v vehicle(type) to get the refit-options of
+ * @param *v first vehicle in consist to get the refit-options of
  * @param sel selected refit cargo-type in the window
  * @return the cargo type that is hightlighted, CT_INVALID if none
  */
@@ -176,6 +176,7 @@ CargoID DrawVehicleRefitWindow(const Vehicle *v, int sel)
 	uint32 cmask;
 	CargoID cid, cargo = CT_INVALID;
 	int y = 25;
+	const Vehicle* u;
 #define show_cargo(ctype) { \
 		byte colour = 16; \
 		if (sel == 0) { \
@@ -187,10 +188,23 @@ CargoID DrawVehicleRefitWindow(const Vehicle *v, int sel)
 		y += 10; \
 }
 
-		/* Check if engine has custom refit or normal ones, and get its bitmasked value.
-		 * Now just and it with the bitmasked available cargo on the current landscape, and
-		* where the bits are set: those are available */
-		cmask = (_engine_refit_masks[v->engine_type] != 0) ? _engine_refit_masks[v->engine_type] : _default_refitmasks[v->type - VEH_Train];
+		/* Check if vehicle has custom refit or normal ones, and get its bitmasked value.
+		 * If its a train, 'or' this with the refit masks of the wagons. Now just 'and'
+		 * it with the bitmask of available cargo on the current landscape, and
+		 * where the bits are set: those are available */
+		cmask = 0;
+		u = v;
+		do {
+			if (_engine_refit_masks[u->engine_type] != 0) { // newgrf custom refit mask
+				cmask |= _engine_refit_masks[u->engine_type];
+			} else if (u->cargo_cap != 0) {
+				// rail wagons cant be refitted by default
+				if (v->type != VEH_Train || !(RailVehInfo(u->engine_type)->flags & RVI_WAGON))
+					cmask |= _default_refitmasks[v->type - VEH_Train];
+			}
+			u = u->next;
+		} while (v->type == VEH_Train && u != NULL);
+
 		cmask &= _landscape_global_cargo_mask[_opt_ptr->landscape];
 
 		/* Check which cargo has been selected from the refit window and draw list */