[GNC] Process Payment for Customer with Credit Balance

[David Burleigh]

How do you process a payment when the customer has a credit balance
sufficient to cover the invoice? In the "process payment" dialog box
(as suggested on the #gnucash irc), I selected both the current invoice
and the earlier pre-payment, and clicked OK. This resulted in recording
the payment for the current invoice, and also recording a debit in the
general ledger for the customer's remaining credit balance, as if I
were issuing a refund. But that is not really what I want to do. I just
want it to deduct the amount of the current invoice from the customer's
credit balance, leaving him with a lower credit balance. There must be
a better way to do this.