I have just finished rewriting a custom payment module for Barclaycard ePDQ, and it's working up to a point.
The problem comes on the return from ePDQ, whereby the user is returned to the checkout_confirm page instead of the /store/order/ORDER_HASH as expected.
I just have a pretty standard purchase_return function with
return new Merchant_response(Merchant_response::COMPLETE,'',$orderid);
The gateway is being sent $this -> param('return_url'); as you'd expect, and if I trap the return I get www.mydomain.mysite/?ACT=16H= etc etc as expected
Any pointers as to why I'm not getting sent to my order page?