From aba49c9a5ac432a951fdd3c087bf4622a371a831 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@lightning.engineering>
Date: Wed, 11 Dec 2019 16:37:02 -0800
Subject: [PATCH] rpcserver: populate features on lnrpc invoices

In the process, we also move the feature serialization into the
invoicesrpc package, so that it can be shared between the invoicesrpc
and main rpcserver.
---
 lnrpc/invoicesrpc/utils.go | 18 ++++++++++++++++++
 rpcserver.go               | 16 +---------------
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/lnrpc/invoicesrpc/utils.go b/lnrpc/invoicesrpc/utils.go
index e659403b4..1d9711c06 100644
--- a/lnrpc/invoicesrpc/utils.go
+++ b/lnrpc/invoicesrpc/utils.go
@@ -7,6 +7,7 @@ import (
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/zpay32"
 )
 
@@ -116,6 +117,7 @@ func CreateRPCInvoice(invoice *channeldb.Invoice,
 		AmtPaid:         int64(invoice.AmtPaid),
 		State:           state,
 		Htlcs:           rpcHtlcs,
+		Features:        CreateRPCFeatures(invoice.Terms.Features),
 	}
 
 	if preimage != channeldb.UnknownPreimage {
@@ -125,6 +127,22 @@ func CreateRPCInvoice(invoice *channeldb.Invoice,
 	return rpcInvoice, nil
 }
 
+// CreateRPCFeatures maps a feature vector into a list of lnrpc.Features.
+func CreateRPCFeatures(fv *lnwire.FeatureVector) []*lnrpc.Feature {
+	features := fv.Features()
+	rpcFeatures := make([]*lnrpc.Feature, 0, len(features))
+	for bit := range features {
+		rpcFeatures = append(rpcFeatures, &lnrpc.Feature{
+			Bit:        uint32(bit),
+			Name:       fv.Name(bit),
+			IsRequired: bit.IsRequired(),
+			IsKnown:    fv.IsKnown(bit),
+		})
+	}
+
+	return rpcFeatures
+}
+
 // CreateRPCRouteHints takes in the decoded form of an invoice's route hints
 // and converts them into the lnrpc type.
 func CreateRPCRouteHints(routeHints [][]zpay32.HopHint) []*lnrpc.RouteHint {
diff --git a/rpcserver.go b/rpcserver.go
index 58d894532..ef8844bd4 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -4632,20 +4632,6 @@ func (r *rpcServer) DecodePayReq(ctx context.Context,
 		paymentAddr = payReq.PaymentAddr[:]
 	}
 
-	// Convert any features on the payment request into a descriptive format
-	// for the rpc.
-	invFeatures := payReq.Features.Features()
-	features := make([]*lnrpc.Feature, 0, len(invFeatures))
-	for bit := range invFeatures {
-		name := payReq.Features.Name(bit)
-		features = append(features, &lnrpc.Feature{
-			Bit:        uint32(bit),
-			Name:       name,
-			IsRequired: bit.IsRequired(),
-			IsKnown:    name != "unknown",
-		})
-	}
-
 	dest := payReq.Destination.SerializeCompressed()
 	return &lnrpc.PayReq{
 		Destination:     hex.EncodeToString(dest),
@@ -4660,7 +4646,7 @@ func (r *rpcServer) DecodePayReq(ctx context.Context,
 		CltvExpiry:      int64(payReq.MinFinalCLTVExpiry()),
 		RouteHints:      routeHints,
 		PaymentAddr:     paymentAddr,
-		Features:        features,
+		Features:        invoicesrpc.CreateRPCFeatures(payReq.Features),
 	}, nil
 }