Train *first = v->First();

	if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);

	/* First make a backup of the order of the train. That way we can do

	 * whatever we want with the order and later on easily revert. */

	TrainList original;

	MakeTrainBackup(original, first);

	/* We need to keep track of the new head and the head of what we're going to sell. */

	Train *new_head = first;

	Train *sell_head = NULL;

	/* Split the train in the wanted way. */

	ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);

	/* We don't need to validate the second train; it's going to be sold. */

	CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);

	if (ret.Failed()) {

		/* Restore the train we had. */

		RestoreTrainBackup(original);

		return ret;

	}

	CommandCost cost(EXPENSES_NEW_VEHICLES);

	for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);

	/* do it? */

	if (flags & DC_EXEC) {

		/* First normalise the sub types of the chain. */

		NormaliseSubtypes(new_head);

		if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {

			/* We are selling the front engine. In this case we want to

			 * 'give' the order, unit number and such to the new head. */

			new_head->orders.list = first->orders.list;

			new_head->AddToShared(first);

			DeleteVehicleOrders(first);

			/* Copy other important data from the front engine */

			new_head->CopyVehicleConfigAndStatistics(first);

			GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit

		} else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {

			OrderBackup::Backup(v, user);

		}

		/* We need to update the information about the train. */

		NormaliseTrainHead(new_head);

		/* We are undoubtedly changing something in the depot and train list. */

		InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);