Fix #6574: Remove go to hangar orders when rebuilding airport

When replacing an airport with another, cancel current orders of type 'go to depot' from aircraft still heading to it if the rebuilt airport doesn't have a hangar (helicopter vs heliport), or if the airplane can't land on the rebuilt airport (airplane vs helistation).

Removes 'go to hangar' orders from all aircraft when replacing an airport with hangar with another without hangar (heliport).

5 files changed, 26 insertions, 8 deletions

diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp
index d6d99ae24..7c3566372 100644
--- a/src/aircraft_cmd.cpp
+++ b/src/aircraft_cmd.cpp
@@ -2103,7 +2103,19 @@ void UpdateAirplanesOnNewStation(const Station *st)
 	FOR_ALL_AIRCRAFT(v) {
 		if (!v->IsNormalAircraft() || v->targetairport != st->index) continue;
 		assert(v->state == FLYING);
+
+		Order *o = &v->current_order;
+		/* The aircraft is heading to a hangar, but the new station doesn't have one,
+		 * or the aircraft can't land on the new station. Cancel current order. */
+		if (o->IsType(OT_GOTO_DEPOT) && !(o->GetDepotOrderType() & ODTFB_PART_OF_ORDERS) && o->GetDestination() == st->index &&
+				(!st->airport.HasHangar() || !CanVehicleUseStation(v, st))) {
+			o->MakeDummy();
+			SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
+		}
 		v->pos = v->previous_pos = AircraftGetEntryPoint(v, ap, rotation);
 		UpdateAircraftCache(v);
 	}
+
+	/* Heliports don't have a hangar. Invalidate all go to hangar orders from all aircraft. */
+	if (!st->airport.HasHangar()) RemoveOrderFromAllVehicles(OT_GOTO_DEPOT, st->index, true);
 }
diff --git a/src/order_backup.cpp b/src/order_backup.cpp
index 597ad13bb..181e3e59d 100644
--- a/src/order_backup.cpp
+++ b/src/order_backup.cpp
@@ -256,15 +256,18 @@ CommandCost CmdClearOrderBackup(TileIndex tile, DoCommandFlag flags, uint32 p1,
  * Removes an order from all vehicles. Triggers when, say, a station is removed.
  * @param type The type of the order (OT_GOTO_[STATION|DEPOT|WAYPOINT]).
  * @param destination The destination. Can be a StationID, DepotID or WaypointID.
+ * @param hangar Only used for airports in the destination.
+ *               When false, remove airport and hangar orders.
+ *               When true, remove either airport or hangar order.
  */
-/* static */ void OrderBackup::RemoveOrder(OrderType type, DestinationID destination)
+/* static */ void OrderBackup::RemoveOrder(OrderType type, DestinationID destination, bool hangar)
 {
 	OrderBackup *ob;
 	FOR_ALL_ORDER_BACKUPS(ob) {
 		for (Order *order = ob->orders; order != NULL; order = order->next) {
 			OrderType ot = order->GetType();
 			if (ot == OT_GOTO_DEPOT && (order->GetDepotActionType() & ODATFB_NEAREST_DEPOT) != 0) continue;
-			if (ot == OT_IMPLICIT || (IsHangarTile(ob->tile) && ot == OT_GOTO_DEPOT)) ot = OT_GOTO_STATION;
+			if (ot == OT_IMPLICIT || (IsHangarTile(ob->tile) && ot == OT_GOTO_DEPOT && !hangar)) ot = OT_GOTO_STATION;
 			if (ot == type && order->GetDestination() == destination) {
 				/* Remove the order backup! If a station/depot gets removed, we can't/shouldn't restore those broken orders. */
 				delete ob;
diff --git a/src/order_backup.h b/src/order_backup.h
index 59404d5be..c56bc0ecc 100644
--- a/src/order_backup.h
+++ b/src/order_backup.h
@@ -63,7 +63,7 @@ public:
 
 	static void ClearGroup(GroupID group);
 	static void ClearVehicle(const Vehicle *v);
-	static void RemoveOrder(OrderType type, DestinationID destination);
+	static void RemoveOrder(OrderType type, DestinationID destination, bool hangar);
 };
 
 /**
diff --git a/src/order_cmd.cpp b/src/order_cmd.cpp
index 83dacdca4..c2805bef3 100644
--- a/src/order_cmd.cpp
+++ b/src/order_cmd.cpp
@@ -1834,8 +1834,11 @@ void CheckOrders(const Vehicle *v)
  * Removes an order from all vehicles. Triggers when, say, a station is removed.
  * @param type The type of the order (OT_GOTO_[STATION|DEPOT|WAYPOINT]).
  * @param destination The destination. Can be a StationID, DepotID or WaypointID.
+ * @param hangar Only used for airports in the destination.
+ *               When false, remove airport and hangar orders.
+ *               When true, remove either airport or hangar order.
  */
-void RemoveOrderFromAllVehicles(OrderType type, DestinationID destination)
+void RemoveOrderFromAllVehicles(OrderType type, DestinationID destination, bool hangar)
 {
 	Vehicle *v;
 
@@ -1848,7 +1851,7 @@ void RemoveOrderFromAllVehicles(OrderType type, DestinationID destination)
 		Order *order;
 
 		order = &v->current_order;
-		if ((v->type == VEH_AIRCRAFT && order->IsType(OT_GOTO_DEPOT) ? OT_GOTO_STATION : order->GetType()) == type &&
+		if ((v->type == VEH_AIRCRAFT && order->IsType(OT_GOTO_DEPOT) && !hangar ? OT_GOTO_STATION : order->GetType()) == type &&
 				v->current_order.GetDestination() == destination) {
 			order->MakeDummy();
 			SetWindowDirty(WC_VEHICLE_VIEW, v->index);
@@ -1862,7 +1865,7 @@ restart:
 
 			OrderType ot = order->GetType();
 			if (ot == OT_GOTO_DEPOT && (order->GetDepotActionType() & ODATFB_NEAREST_DEPOT) != 0) continue;
-			if (ot == OT_IMPLICIT || (v->type == VEH_AIRCRAFT && ot == OT_GOTO_DEPOT)) ot = OT_GOTO_STATION;
+			if (ot == OT_IMPLICIT || (v->type == VEH_AIRCRAFT && ot == OT_GOTO_DEPOT && !hangar)) ot = OT_GOTO_STATION;
 			if (ot == type && order->GetDestination() == destination) {
 				/* We want to clear implicit orders, but we don't want to make them
 				 * dummy orders. They should just vanish. Also check the actual order
@@ -1896,7 +1899,7 @@ restart:
 		}
 	}
 
-	OrderBackup::RemoveOrder(type, destination);
+	OrderBackup::RemoveOrder(type, destination, hangar);
 }
 
 /**
diff --git a/src/order_func.h b/src/order_func.h
index 54977181a..df9939428 100644
--- a/src/order_func.h
+++ b/src/order_func.h
@@ -17,7 +17,7 @@
 #include "company_type.h"
 
 /* Functions */
-void RemoveOrderFromAllVehicles(OrderType type, DestinationID destination);
+void RemoveOrderFromAllVehicles(OrderType type, DestinationID destination, bool hangar = false);
 void InvalidateVehicleOrder(const Vehicle *v, int data);
 void CheckOrders(const Vehicle*);
 void DeleteVehicleOrders(Vehicle *v, bool keep_orderlist = false, bool reset_order_indices = true);