Fix OpenTTD#6493: CheckIfAircraftNeedsService - Try to service aircra…

…ft at a hangar outside the order list

If a helicopter needs to be sent to a hangar during automatic service, and there are no airports with hangars in the orders (travelling between heliports), a nearby hangar outside the orders will be searched. If the distance to a found hangar is shorter than the distance to the helistation/airport the helicopter is headed to, the helicopter is sent to that hangar.

src/aircraft_cmd.cpp

@@ -410,7 +410,10 @@ bool Aircraft::FindClosestDepot(TileIndex *location, DestinationID *destination,
 
 static void CheckIfAircraftNeedsService(Aircraft *v)
 {
-	if (Company::Get(v->owner)->settings.vehicle.servint_aircraft == 0 || !v->NeedsAutomaticServicing()) return;
+	bool needs_automatic_servicing = v->NeedsAutomaticServicing();
+	bool has_pending_replace = v->HasPendingReplace();
+	if (Company::Get(v->owner)->settings.vehicle.servint_aircraft == 0 || (!needs_automatic_servicing &&
+			(!has_pending_replace || v->subtype != AIR_HELICOPTER || !_settings_game.order.serviceathelipad))) return;
 	if (v->IsChainInDepot()) {
 		VehicleServiceInDepot(v);
 		return;
@@ -431,6 +434,39 @@ static void CheckIfAircraftNeedsService(Aircraft *v)
 	} else if (v->current_order.IsType(OT_GOTO_DEPOT)) {
 		v->current_order.MakeDummy();
 		SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
+	} else {
+		bool hangar_in_o = false;
+		const Order *o;
+
+		/* Is there at least an airport coupled with a hangar in the orders? */
+		FOR_VEHICLE_ORDERS(v, o) {
+			if (o->IsType(OT_GOTO_STATION)) {
+				const Station *ost = Station::Get(o->GetDestination());
+				if (ost->airport.HasHangar() ||
+						/* Helicopters can be serviced at helipads as long as there is no pending replace and serviceathelipad is enabled */
+						(v->subtype == AIR_HELICOPTER && !has_pending_replace && _settings_game.order.serviceathelipad && ost->airport.GetFTA()->num_helipads)) {
+					hangar_in_o = true;
+					break;
+				}
+			}
+		}
+
+		if (!hangar_in_o) {
+			/* there's no airport coupled with a hangar in the orders, so look for a nearby hangar */
+			const StationID nearest_hangar = FindNearestHangar(v);
+
+			/* v->tile can't be used here, when aircraft is flying v->tile is set to 0 */
+			TileIndex vtile = TileVirtXY(v->x_pos, v->y_pos);
+
+			if (nearest_hangar != INVALID_STATION && ((has_pending_replace && v->subtype == AIR_HELICOPTER && _settings_game.order.serviceathelipad && !needs_automatic_servicing) ||
+					/* is nearest hangar closer than destination? */
+					DistanceSquare(vtile, Station::Get(nearest_hangar)->airport.tile) <= DistanceSquare(vtile, st->airport.tile))) {
+				/* defer destination, service aircraft at that hangar now */
+				v->current_order.MakeGoToDepot(nearest_hangar, ODTFB_SERVICE);
+				v->SetDestTile(v->GetOrderStationLocation(nearest_hangar));
+				SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
+			}
+		}
 	}
 }
 
@@ -1544,6 +1580,14 @@ static void AircraftEventHandler_AtTerminal(Aircraft *v, const AirportFTAClass *
 	/* airport-road is free. We either have to go to another airport, or to the hangar
 	 * ---> start moving */
 
+	if (Station::Get(v->targetairport)->airport.HasHangar()) {
+		if (v->NeedsAutomaticServicing() || (v->subtype == AIR_HELICOPTER && v->HasPendingReplace() && _settings_game.order.serviceathelipad &&
+				(!v->HasDepotOrder() || !(v->current_order.IsType(OT_GOTO_DEPOT) && v->current_order.GetDepotOrderType() != ODTFB_SERVICE)))) {
+			v->current_order.MakeGoToDepot(v->targetairport, ODTFB_SERVICE);
+			SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
+		}
+	}
+
 	bool go_to_hangar = false;
 	switch (v->current_order.GetType()) {
 		case OT_GOTO_STATION: // ready to fly to another airport
@@ -1602,13 +1646,6 @@ static void AircraftEventHandler_HeliTakeOff(Aircraft *v, const AirportFTAClass
 
 	/* get the next position to go to, differs per airport */
 	AircraftNextAirportPos_and_Order(v);
-
-	/* Send the helicopter to a hangar if needed for replacement */
-	if (v->NeedsAutomaticServicing()) {
-		Backup<CompanyID> cur_company(_current_company, v->owner, FILE_LINE);
-		DoCommand(v->tile, v->index | DEPOT_SERVICE | DEPOT_LOCATE_HANGAR, 0, DC_EXEC, CMD_SEND_VEHICLE_TO_DEPOT);
-		cur_company.Restore();
-	}
 }
 
 static void AircraftEventHandler_Flying(Aircraft *v, const AirportFTAClass *apc)
@@ -1653,13 +1690,6 @@ static void AircraftEventHandler_Landing(Aircraft *v, const AirportFTAClass *apc
 {
 	v->state = ENDLANDING;
 	AircraftLandAirplane(v);  // maybe crash airplane
-
-	/* check if the aircraft needs to be replaced or renewed and send it to a hangar if needed */
-	if (v->NeedsAutomaticServicing()) {
-		Backup<CompanyID> cur_company(_current_company, v->owner, FILE_LINE);
-		DoCommand(v->tile, v->index | DEPOT_SERVICE, 0, DC_EXEC, CMD_SEND_VEHICLE_TO_DEPOT);
-		cur_company.Restore();
-	}
 }
 
 static void AircraftEventHandler_HeliLanding(Aircraft *v, const AirportFTAClass *apc)