From 29af6e6932f72b317b583c573b1bf74c294a9acd Mon Sep 17 00:00:00 2001
From: Olaoluwa Osuntokun <laolu32@gmail.com>
Date: Mon, 21 Aug 2017 22:42:50 -0700
Subject: [PATCH] lnwire: shift fields in NodeAnnouncment to match recent
 BOLT-0007 changes

This commit modifies the NodeAnnouncement message to ensure that it
matches the current spec ordering. The spec was recently modified to
place the feature vector first to allow for future changes to the
fields to be forwards compatible.
---
 lnwire/lnwire_test.go       |  4 ++--
 lnwire/node_announcement.go | 31 ++++++++++++++++---------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/lnwire/lnwire_test.go b/lnwire/lnwire_test.go
index 0f7ecb04..778a8f15 100644
--- a/lnwire/lnwire_test.go
+++ b/lnwire/lnwire_test.go
@@ -384,14 +384,14 @@ func TestLightningWireProtocol(t *testing.T) {
 
 			req := NodeAnnouncement{
 				Signature: testSig,
+				Features:  randFeatureVector(r),
 				Timestamp: uint32(r.Int31()),
-				Alias:     newAlias(a[:]),
+				Alias:     a,
 				RGBColor: RGB{
 					red:   uint8(r.Int31()),
 					green: uint8(r.Int31()),
 					blue:  uint8(r.Int31()),
 				},
-				Features:  randFeatureVector(r),
 				Addresses: testAddrs,
 			}
 			req.Features.featuresMap = nil
diff --git a/lnwire/node_announcement.go b/lnwire/node_announcement.go
index f0cbabf6..3ee1ada2 100644
--- a/lnwire/node_announcement.go
+++ b/lnwire/node_announcement.go
@@ -58,26 +58,25 @@ type NodeAnnouncement struct {
 	// Signature is used to prove the ownership of node id.
 	Signature *btcec.Signature
 
-	// Timestamp allows ordering in the case of multiple
-	// announcements.
+	// Features is the list of protocol features this node supports.
+	Features *FeatureVector
+
+	// Timestamp allows ordering in the case of multiple announcements.
 	Timestamp uint32
 
 	// NodeID is a public key which is used as node identification.
 	NodeID *btcec.PublicKey
 
-	// RGBColor is used to customize their node's appearance in
-	// maps and graphs
+	// RGBColor is used to customize their node's appearance in maps and
+	// graphs
 	RGBColor RGB
 
-
-	// Features is the list of protocol features this node supports.
-	Features *FeatureVector
 	// Alias is used to customize their node's appearance in maps and
 	// graphs
 	Alias NodeAlias
 
-	// Address includes two specification fields: 'ipv6' and 'port' on which
-	// the node is accepting incoming connections.
+	// Address includes two specification fields: 'ipv6' and 'port' on
+	// which the node is accepting incoming connections.
 	Addresses []net.Addr
 }
 
@@ -92,11 +91,11 @@ var _ Message = (*NodeAnnouncement)(nil)
 func (a *NodeAnnouncement) Decode(r io.Reader, pver uint32) error {
 	return readElements(r,
 		&a.Signature,
+		&a.Features,
 		&a.Timestamp,
 		&a.NodeID,
 		&a.RGBColor,
-		&a.Alias,
-		&a.Features,
+		a.Alias[:],
 		&a.Addresses,
 	)
 }
@@ -107,11 +106,11 @@ func (a *NodeAnnouncement) Decode(r io.Reader, pver uint32) error {
 func (a *NodeAnnouncement) Encode(w io.Writer, pver uint32) error {
 	return writeElements(w,
 		a.Signature,
+		a.Features,
 		a.Timestamp,
 		a.NodeID,
 		a.RGBColor,
-		a.Alias,
-		a.Features,
+		a.Alias[:],
 		a.Addresses,
 	)
 }
@@ -138,16 +137,18 @@ func (a *NodeAnnouncement) DataToSign() ([]byte, error) {
 	// We should not include the signatures itself.
 	var w bytes.Buffer
 	err := writeElements(&w,
+		a.Features,
 		a.Timestamp,
 		a.NodeID,
 		a.RGBColor,
-		a.Alias,
-		a.Features,
+		a.Alias[:],
 		a.Addresses,
 	)
 	if err != nil {
 		return nil, err
 	}
 
+	// TODO(roasbeef): also capture the excess bytes in msg padded out?
+
 	return w.Bytes(), nil
 }