A user got away with Free shipping, order was stored with id_carrier=0

[Mercader Virtual]

Hi,

For some weird reason, an order was created without a carrier, so user didn't pay for shipping. This should've not happened in anyway. The system should've not allowed the user to move forward. Funnily enough, I can't reproduce it. So probably user messed around with the browser code.

Checking the code, it seems that as long as delivery_option is not empty, it passes.

My question is, how can I force the delivery_option to be not null and not "0", otherwise throw an error.

I guess the place where I need to force that is here:

public function handleRequest(array $requestParams = array())
    {


        if (isset($requestParams['delivery_option'])) {
            $this->getCheckoutSession()->setDeliveryOption(
                $requestParams['delivery_option']
            );
            $this->getCheckoutSession()->setRecyclable(
                isset($requestParams['recyclable']) ? $requestParams['recyclable'] : false
            );
            $this->getCheckoutSession()->setGift(
                isset($requestParams['gift']) ? $requestParams['gift'] : false,
                (isset($requestParams['gift']) && isset($requestParams['gift_message'])) ? $requestParams['gift_message'] : ''
            );
        }

        if (isset($requestParams['delivery_message'])) {
            $this->getCheckoutSession()->setMessage($requestParams['delivery_message']);
        }

        if ($this->step_is_reachable && isset($requestParams['confirmDeliveryOption'])) {
            // we're done if
            // - the step was reached (= all previous steps complete)
            // - user has clicked on "continue"
            // - there are delivery options
            // - the is a selected delivery option
            // - the module associated to the delivery option confirms
            $deliveryOptions = $this->getCheckoutSession()->getDeliveryOptions();
            $this->step_is_complete =
                !empty($deliveryOptions) && $this->getCheckoutSession()->getSelectedDeliveryOption() && $this->isModuleComplete($requestParams)
            ;
        }

        $this->setTitle($this->getTranslator()->trans('Shipping Method', array(), 'Shop.Theme.Checkout'));

        Hook::exec('actionCarrierProcess', array('cart' => $this->getCheckoutSession()->getCart()));
    }

 

Can you please tell me how can I deal with this issue, what part of the code I need to reinforce, or if there's a better way to prevent '0' entries in id_carrier.

Thanks.