(svn r5822) - NewGRF: add support for callback 31, vehicle start/stop check. This allows a set to disallow a vehicle from being started, i.e. to not be able to leave the depot. This is almost a partner to callback 1D.

1 files changed, 9 insertions, 0 deletions

diff --git a/train_cmd.c b/train_cmd.c
index 1bcc1bffa..8afe5d75b 100644
--- a/train_cmd.c
+++ b/train_cmd.c
@@ -1227,6 +1227,7 @@ int32 CmdMoveRailVehicle(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 int32 CmdStartStopTrain(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
 	Vehicle *v;
+	uint16 callback;
 
 	if (!IsVehicleIndex(p1)) return CMD_ERROR;
 
@@ -1234,6 +1235,14 @@ int32 CmdStartStopTrain(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 
 	if (v->type != VEH_Train || !CheckOwnership(v->owner)) return CMD_ERROR;
 
+	/* Check if this train can be started/stopped. The callback will fail or
+	 * return 0xFF if it can. */
+	callback = GetVehicleCallback(CBID_VEHICLE_START_STOP_CHECK, 0, 0, v->engine_type, v);
+	if (callback != CALLBACK_FAILED && callback != 0xFF) {
+		StringID error = GetGRFStringID(GetEngineGRFID(v->engine_type), 0xD000 + callback);
+		return_cmd_error(error);
+	}
+
 	if (flags & DC_EXEC) {
 		if (v->vehstatus & VS_STOPPED && v->u.rail.track == 0x80) {
 			DeleteVehicleNews(p1, STR_8814_TRAIN_IS_WAITING_IN_DEPOT);