Entering a Coupon code causes Payment Form Reset

[boonep]

Currently, if the Payment Form has been filled out on the checkout page...

...and then the user subsequently enters a valid coupon code. The Payment form is reset to its empty state, and all entered payment information is removed.

This is generally a bad experience, but especially in the responsive mobile view because coupon code entry section is presented after the payment form, so the user naturally enters their payment information, then enters a coupon, and then has to reenter all of their payment information.