Function CopyHeadSpecificThings

src/autoreplace_cmd.cpp:416–449

* Copy head specific things to the new vehicle chain after it was successfully constructed * @param old_head The old front vehicle (no wagons attached anymore) * @param new_head The new head of the completely replaced vehicle chain * @param flags the command flags to use */

 * @param flags the command flags to use
 */
static CommandCost CopyHeadSpecificThings(Vehicle *old_head, Vehicle *new_head, DoCommandFlags flags)
{
	CommandCost cost = CommandCost();

	/* Share orders */
	if (cost.Succeeded() && old_head != new_head) cost.AddCost(Command<CMD_CLONE_ORDER>::Do(DoCommandFlag::Execute, CO_SHARE, new_head->index, old_head->index));

	/* Copy group membership */
	if (cost.Succeeded() && old_head != new_head) cost.AddCost(std::get<0>(Command<CMD_ADD_VEHICLE_GROUP>::Do(DoCommandFlag::Execute, old_head->group_id, new_head->index, false, VehicleListIdentifier{})));

	/* Perform start/stop check whether the new vehicle suits newgrf restrictions etc. */
	if (cost.Succeeded()) {
		/* Start the vehicle, might be denied by certain things */
		assert(new_head->vehstatus.Test(VehState::Stopped));
		cost.AddCost(DoCmdStartStopVehicle(new_head, true));

		/* Stop the vehicle again, but do not care about evil newgrfs allowing starting but not stopping :p */
		if (cost.Succeeded()) cost.AddCost(DoCmdStartStopVehicle(new_head, false));
	}

	/* Last do those things which do never fail (resp. we do not care about), but which are not undo-able */
	if (cost.Succeeded() && old_head != new_head && flags.Test(DoCommandFlag::Execute)) {
		/* Copy other things which cannot be copied by a command and which shall not stay reset from the build vehicle command */
		new_head->CopyVehicleConfigAndStatistics(old_head);
		GroupStatistics::AddProfitLastYear(new_head);

		/* Switch vehicle windows/news to the new vehicle, so they are not closed/deleted when the old vehicle is sold */
		ChangeVehicleViewports(old_head->index, new_head->index);
		ChangeVehicleViewWindow(old_head->index, new_head->index);
		ChangeVehicleNews(old_head->index, new_head->index);
	}

	return cost;
}

/**
 * Replace a single unit in a free wagon chain