Allow drive-through road stops to be one-way

src/saveload/afterload.cpp

@@ -3787,6 +3787,14 @@ bool AfterLoadGame()
 		}
 	}
 
+	if (SlXvIsFeatureMissing(XSLFI_ONE_WAY_DT_ROAD_STOP)) {
+		for (TileIndex t = 0; t < map_size; t++) {
+			if (IsDriveThroughStopTile(t)) {
+				SetDriveThroughStopDisallowedRoadDirections(t, DRD_NONE);
+			}
+		}
+	}
+
 	InitializeRoadGUI();
 
 	/* This needs to be done after conversion. */

src/saveload/extended_ver_sl.cpp

@@ -136,6 +136,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_THROUGH_TRAIN_DEPOT,    XSCF_NULL,                1,   1, "drive_through_train_depot", nullptr, nullptr, nullptr        },
 	{ XSLFI_MORE_VEHICLE_ORDERS,    XSCF_NULL,                1,   1, "more_veh_orders",           nullptr, nullptr, nullptr        },
 	{ XSLFI_ORDER_FLAGS_EXTRA,      XSCF_NULL,                1,   1, "order_flags_extra",         nullptr, nullptr, nullptr        },
+	{ XSLFI_ONE_WAY_DT_ROAD_STOP,   XSCF_NULL,                1,   1, "one_way_dt_road_stop",      nullptr, nullptr, nullptr        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker
 };
 

src/saveload/extended_ver_sl.h

@@ -90,6 +90,7 @@ enum SlXvFeatureIndex {
 	XSLFI_THROUGH_TRAIN_DEPOT,                    ///< Drive-through train depots
 	XSLFI_MORE_VEHICLE_ORDERS,                    ///< More vehicle orders - VehicleOrderID is 16 bits instead of 8
 	XSLFI_ORDER_FLAGS_EXTRA,                      ///< Order flags field extra size
+	XSLFI_ONE_WAY_DT_ROAD_STOP,                   ///< One-way drive-through road stops
 
 	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