Add depot order flag for specific depot

Use upper half of order flags for extra depot flags

See: #302

src/order_base.h

@@ -324,6 +324,8 @@ public:
 	inline OrderDepotTypeFlags GetDepotOrderType() const { return (OrderDepotTypeFlags)GB(this->flags, 0, 3); }
 	/** What are we going to do when in the depot. */
 	inline OrderDepotActionFlags GetDepotActionType() const { return (OrderDepotActionFlags)GB(this->flags, 4, 3); }
+	/** Extra depot flags. */
+	inline OrderDepotExtraFlags GetDepotExtraFlags() const { return (OrderDepotExtraFlags)GB(this->flags, 8, 8); }
 	/** What waypoint flags? */
 	inline OrderWaypointFlags GetWaypointFlags() const { return (OrderWaypointFlags)GB(this->flags, 0, 3); }
 	/** What variable do we have to compare? */
@@ -385,6 +387,8 @@ public:
 	inline void SetDepotOrderType(OrderDepotTypeFlags depot_order_type) { SB(this->flags, 0, 3, depot_order_type); }
 	/** Set what we are going to do in the depot. */
 	inline void SetDepotActionType(OrderDepotActionFlags depot_service_type) { SB(this->flags, 4, 3, depot_service_type); }
+	/** Set what we are going to do in the depot. */
+	inline void SetDepotExtraFlags(OrderDepotExtraFlags depot_extra_flags) { SB(this->flags, 8, 8, depot_extra_flags); }
 	/** Set waypoint flags. */
 	inline void SetWaypointFlags(OrderWaypointFlags waypoint_flags) { SB(this->flags, 0, 3, waypoint_flags); }
 	/** Set variable we have to compare. */

src/order_type.h

@@ -117,6 +117,15 @@ enum OrderDepotActionFlags {
 };
 DECLARE_ENUM_AS_BIT_SET(OrderDepotActionFlags)
 
+/**
+ * Extra depot flags.
+ */
+enum OrderDepotExtraFlags {
+	ODEF_NONE           = 0,      ///< No flags.
+	ODEFB_SPECIFIC      = 1 << 0, ///< This order is for a specific depot.
+};
+DECLARE_ENUM_AS_BIT_SET(OrderDepotExtraFlags)
+
 /**
  * Flags for go to waypoint orders
  */

src/saveload/extended_ver_sl.cpp

@@ -154,6 +154,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_STATION_CARGO_HISTORY,  XSCF_NULL,                1,   1, "station_cargo_history",     nullptr, nullptr, nullptr        },
 	{ XSLFI_TRAIN_SPEED_ADAPTATION, XSCF_NULL,                1,   1, "train_speed_adaptation",    nullptr, nullptr, "TSAS"         },
 	{ XSLFI_EXTRA_STATION_NAMES,    XSCF_NULL,                1,   1, "extra_station_names",       nullptr, nullptr, nullptr        },
+	{ XSLFI_DEPOT_ORDER_EXTRA_FLAGS,XSCF_IGNORABLE_UNKNOWN,   1,   1, "depot_order_extra_flags",   nullptr, nullptr, nullptr        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker
 };
 

src/saveload/extended_ver_sl.h

@@ -108,6 +108,7 @@ enum SlXvFeatureIndex {
 	XSLFI_STATION_CARGO_HISTORY,                  ///< Station waiting cargo history
 	XSLFI_TRAIN_SPEED_ADAPTATION,                 ///< Train speed adaptation
 	XSLFI_EXTRA_STATION_NAMES,                    ///< Extra station names
+	XSLFI_DEPOT_ORDER_EXTRA_FLAGS,                ///< Depot order extra flags
 
 	XSLFI_RIFF_HEADER_60_BIT,                     ///< Size field in RIFF chunk header is 60 bit
 	XSLFI_HEIGHT_8_BIT,                           ///< Map tile height is 8 bit instead of 4 bit, but savegame version may be before this became true in trunk

src/vehicle.cpp

@@ -2478,6 +2478,13 @@ void VehicleEnterDepot(Vehicle *v)
 			return;
 		}
 
+		/* Test whether we are heading for this depot. If not, do nothing. */
+		if ((v->current_order.GetDepotExtraFlags() & ODEFB_SPECIFIC) &&
+				(v->type == VEH_AIRCRAFT ? v->current_order.GetDestination() != GetStationIndex(v->tile) : v->dest_tile != v->tile)) {
+			/* We are heading for another depot, keep driving. */
+			return;
+		}
+
 		if (v->current_order.GetDepotActionType() & ODATFB_SELL) {
 			_vehicles_to_sell.insert(v->index);
 			return;
@@ -3600,6 +3607,9 @@ CommandCost Vehicle::SendToDepot(DoCommandFlag flags, DepotCommand command, Tile
 		} else if (!(command & DEPOT_SERVICE)) {
 			this->current_order.SetDepotActionType(ODATFB_HALT);
 		}
+		if (command & DEPOT_SPECIFIC) {
+			this->current_order.SetDepotExtraFlags(ODEFB_SPECIFIC);
+		}
 		SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, WID_VV_START_STOP);
 
 		/* If there is no depot in front and the train is not already reversing, reverse automatically (trains only) */