CBSubs and Quickpay - two users have paid for two years subscription ??

I'm also seeing a timing issue with IPNs from QuickPay itself. In my tests I have a pending and processed IPN sent by QuickPay with the exact same timestamps in the IPN data. That's a problem that will also need to be dealt with. Seams they're sending multiple HTTP requests at once instead of properly staging them. Even the "operations" data for the IPN has the exact same timestamp for pending and processed operations.

Ok, have implemented delayed processing of PDT (by 3 seconds) and delayed processing of pending IPNs (by 2 seconds). This gives priority to IPNs followed by priority to processed IPNs. Have made 40 different test payments and confirmed fixing of the overlapping issues. QuickPay really needs to take timings more seriously though. Sending a pending and processed IPN with literally the exact same timestamps is not a good idea.

I've patched your install and have created a bug ticket to include the fix in next CBSubs release, but for now your install has been fixed.

forge.joomlapolis.com/issues/9093

Thank you very much. I have forwarded your last two messages to the Quickpay helpdesk and asked them to take a look at the problem.

Here are two responses from Quickpay support:

"Callbacks can come pretty close to each other, but you should always check the payment status through the API."

"The Callbacks were send 2022-12-19 13:30:34.582 and 2022-12-19 13:30:34.659 so not at the same time, but close."

"Callbacks can come pretty close to each other, but you should always check the payment status through the API."

Then there's no point in having notifications with verified signatures. It's causing a server communication when not necessary.

"The Callbacks were send 2022-12-19 13:30:34.582 and 2022-12-19 13:30:34.659 so not at the same time, but close."

That's close enough to cause server response handling to happen at the same time. It makes no sense to be sending a pending and processed notification that close to one another and suggests they happened during the same payment process in which case it should've never sent the pending notification and only sent the processed notification.

At any rate the delayed handling should fix your issue. Please let me know if you see any further issues in this regard and we'll review other solutions.

Here is the final answer from Quickpay support:

"HiIt's up to you, if you want to use callback, we don't send them, if you don't specify a callback.We are not going to change the callback system."