Fix bug confirming offline order

The point of confirming an offline order is to just accept whatever amount is
offered in the order. However, the code was re-calculating the order total causing
the vendor to reject the order in some instances.

Author: cpacia

core/confirmation.go

@@ -17,7 +17,7 @@ import (
 	"github.com/golang/protobuf/ptypes"
 )
 
-func (n *OpenBazaarNode) NewOrderConfirmation(contract *pb.RicardianContract, addressRequest bool) (*pb.RicardianContract, error) {
+func (n *OpenBazaarNode) NewOrderConfirmation(contract *pb.RicardianContract, addressRequest, calculateNewTotal bool) (*pb.RicardianContract, error) {
 	oc := new(pb.OrderConfirmation)
 	// Calculate order ID
 	orderID, err := n.CalcOrderId(contract.BuyerOrder)
@@ -61,9 +61,13 @@ func (n *OpenBazaarNode) NewOrderConfirmation(contract *pb.RicardianContract, ad
 		oc.PaymentAddress = contract.BuyerOrder.Payment.Address
 	}
 
-	oc.RequestedAmount, err = n.CalculateOrderTotal(contract)
-	if err != nil {
-		return nil, err
+	if calculateNewTotal {
+		oc.RequestedAmount, err = n.CalculateOrderTotal(contract)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		oc.RequestedAmount = contract.BuyerOrder.Payment.Amount
 	}
 	contract.VendorOrderConfirmation = oc
 	contract, err = n.SignOrderConfirmation(contract)
@@ -74,7 +78,7 @@ func (n *OpenBazaarNode) NewOrderConfirmation(contract *pb.RicardianContract, ad
 }
 
 func (n *OpenBazaarNode) ConfirmOfflineOrder(contract *pb.RicardianContract, records []*wallet.TransactionRecord) error {
-	contract, err := n.NewOrderConfirmation(contract, false)
+	contract, err := n.NewOrderConfirmation(contract, false, false)
 	if err != nil {
 		return err
 	}

net/service/handlers.go

@@ -272,7 +272,7 @@ func (service *OpenBazaarService) handleOrder(peer peer.ID, pmes *pb.Message, op
 			log.Error("Calculated a different payment amount")
 			return errorResponse("Calculated a different payment amount"), nil
 		}
-		contract, err = service.node.NewOrderConfirmation(contract, true)
+		contract, err = service.node.NewOrderConfirmation(contract, true, true)
 		if err != nil {
 			log.Error(err)
 			return errorResponse("Error building order confirmation"), nil
@@ -345,7 +345,7 @@ func (service *OpenBazaarService) handleOrder(peer peer.ID, pmes *pb.Message, op
 			return errorResponse(err.Error()), err
 		}
 		service.node.Wallet.AddWatchedScript(script)
-		contract, err = service.node.NewOrderConfirmation(contract, false)
+		contract, err = service.node.NewOrderConfirmation(contract, false, true)
 		if err != nil {
 			log.Error(err)
 			return errorResponse("Error building order confirmation"), nil