'Empty' objects assigned to the order when an user without addresses goes to checkout

When an user without (default) addresses in the address book tries to checkout, two 'empty' objects are assigned to the $order->uc_addresses array, while it should have been two UcAddressesAddress instances.

While this previously didn't lead to direct problems, it now does with this change in the latest commit:

           }
           $address = uc_addresses_new_address_from_order($order, $order_address_type);
         }
+        $address->address_type = $address_type;
         $order->uc_addresses[$address_type] = $address;
       }
       break;
@@ -855,6 +856,7 @@ function uc_addresses_uc_order($op, &$order, $arg2) {
           // Construct new address.
           $address = uc_addresses_new_address_from_order($order, $order_address_type);
         }
+        $address->address_type = $address_type;
         $order->uc_addresses[$address_type] = $address;
       }
       break;

This can result into the Call to undefined method stdClass::getField() when an user without addresses enters checkout. It also broke a part of the checkout test.

I'm working on a fix.