Function CmdMoveOrder

src/order_cmd.cpp:1074–1159

* Move an order inside the orderlist * @param flags operation to perform * @param veh the ID of the vehicle * @param moving_order the order to move * @param target_order the target order * @return the cost of this operation or an error * @note The target order will move one place down in the orderlist * if you move the order upwards else it'll move it one place down */

 *  if you move the order upwards else it'll move it one place down
 */
CommandCost CmdMoveOrder(DoCommandFlags flags, VehicleID veh, VehicleOrderID moving_order, VehicleOrderID target_order)
{
	Vehicle *v = Vehicle::GetIfValid(veh);
	if (v == nullptr || !v->IsPrimaryVehicle()) return CMD_ERROR;

	CommandCost ret = CheckOwnership(v->owner);
	if (ret.Failed()) return ret;

	/* Don't make senseless movements */
	if (moving_order >= v->GetNumOrders() || target_order >= v->GetNumOrders() ||
			moving_order == target_order || v->GetNumOrders() <= 1) return CMD_ERROR;

	Order *moving_one = v->GetOrder(moving_order);
	/* Don't move an empty order */
	if (moving_one == nullptr) return CMD_ERROR;

	if (flags.Test(DoCommandFlag::Execute)) {
		v->orders->MoveOrder(moving_order, target_order);

		/* Update shared list */
		Vehicle *u = v->FirstShared();

		DeleteOrderWarnings(u);

		for (; u != nullptr; u = u->NextShared()) {
			/* Update the current order.
			 * There are multiple ways to move orders, which result in cur_implicit_order_index
			 * and cur_real_order_index to not longer make any sense. E.g. moving another
			 * real order between them.
			 *
			 * Basically one could choose to preserve either of them, but not both.
			 * While both ways are suitable in this or that case from a human point of view, neither
			 * of them makes really sense.
			 * However, from an AI point of view, preserving cur_real_order_index is the most
			 * predictable and transparent behaviour.
			 *
			 * With that decision it basically does not matter what we do to cur_implicit_order_index.
			 * If we change orders between the implicit- and real-index, the implicit orders are mostly likely
			 * completely out-dated anyway. So, keep it simple and just keep cur_implicit_order_index as well.
			 * The worst which can happen is that a lot of implicit orders are removed when reaching current_order.
			 */
			if (u->cur_real_order_index == moving_order) {
				u->cur_real_order_index = target_order;
			} else if (u->cur_real_order_index > moving_order && u->cur_real_order_index <= target_order) {
				u->cur_real_order_index--;
			} else if (u->cur_real_order_index < moving_order && u->cur_real_order_index >= target_order) {
				u->cur_real_order_index++;
			}

			if (u->cur_implicit_order_index == moving_order) {
				u->cur_implicit_order_index = target_order;
			} else if (u->cur_implicit_order_index > moving_order && u->cur_implicit_order_index <= target_order) {
				u->cur_implicit_order_index--;
			} else if (u->cur_implicit_order_index < moving_order && u->cur_implicit_order_index >= target_order) {
				u->cur_implicit_order_index++;
			}
			/* Unbunching data is no longer valid. */
			u->ResetDepotUnbunching();