Missing orders for payments made via an improper payment API

[mgesing]

In case of payment API where the payment transaction is created by the store but the payment is executed by the payment provider (e.g. PostFinance), a payment without an order may occur. The order may be lost in the very short period between payment and store redirection/order creation (e.g. by closing the browser window). This problem does not occur with payment providers (such as PayPal or AmazonPay) where transaction creation and payment execution are both carried out by the store.

One possible solution would be to create transient orders before the payment, which would then be converted into regular orders by the payment plugin in case of a success (after being returned to the store). In case of an error, the admin could check transient orders manually via the backend and convert or void them.