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).

1 files changed, 12 insertions, 0 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);
 }