During onepage checkout, a customer has the option to enter a new shipping address and save this address to their profile. This functionality is broken (probably due to custom code) and I'm attempting to debug it.
Mage_Checkout_Model_Type_Onepage::saveShipping, a call is made to
$address->setSaveInAddressBook. It's my understanding that this flag should cause the address to be saved at the final step of checkout.
What block of code actually causes this address to be saved? I'd like to debug the save point and work backwards to find my bug, but I can't find the point where the shipping address is saved.