From e713205eeae953b71e72e252572b4c46e6549bba Mon Sep 17 00:00:00 2001
From: Wilmer Paulino <wilmer.paulino@gmail.com>
Date: Mon, 22 Mar 2021 15:31:16 -0700
Subject: [PATCH] discovery: add missing error channel sends in
 processNetworkAnnouncement

Without the error channel sends, we would block the gossip message
stream upon receiving a premature channel announcement.
---
 discovery/gossiper.go      | 14 ++++++--------
 discovery/gossiper_test.go | 31 ++++++-------------------------
 2 files changed, 12 insertions(+), 33 deletions(-)

diff --git a/discovery/gossiper.go b/discovery/gossiper.go
index bb612850..750f4e24 100644
--- a/discovery/gossiper.go
+++ b/discovery/gossiper.go
@@ -1612,8 +1612,7 @@ func (d *AuthenticatedGossiper) processNetworkAnnouncement(
 		}
 
 		// If the advertised inclusionary block is beyond our knowledge
-		// of the chain tip, then we'll put the announcement in limbo
-		// to be fully verified once we advance forward in the chain.
+		// of the chain tip, then we'll ignore for it now.
 		d.Lock()
 		if nMsg.isRemote && isPremature(msg.ShortChannelID, 0) {
 			log.Infof("Announcement for chan_id=(%v), is "+
@@ -1623,6 +1622,7 @@ func (d *AuthenticatedGossiper) processNetworkAnnouncement(
 				msg.ShortChannelID.BlockHeight,
 				d.bestHeight)
 			d.Unlock()
+			nMsg.err <- nil
 			return nil
 		}
 		d.Unlock()
@@ -2132,16 +2132,14 @@ func (d *AuthenticatedGossiper) processNetworkAnnouncement(
 		// By the specification, channel announcement proofs should be
 		// sent after some number of confirmations after channel was
 		// registered in bitcoin blockchain. Therefore, we check if the
-		// proof is premature.  If so we'll halt processing until the
-		// expected announcement height.  This allows us to be tolerant
-		// to other clients if this constraint was changed.
+		// proof is premature.
 		d.Lock()
 		if isPremature(msg.ShortChannelID, d.cfg.ProofMatureDelta) {
-			log.Infof("Premature proof announcement, "+
-				"current block height lower than needed: %v <"+
-				" %v, add announcement to reprocessing batch",
+			log.Infof("Premature proof announcement, current "+
+				"block height lower than needed: %v < %v",
 				d.bestHeight, needBlockHeight)
 			d.Unlock()
+			nMsg.err <- nil
 			return nil
 		}
 		d.Unlock()
diff --git a/discovery/gossiper_test.go b/discovery/gossiper_test.go
index 067296c8..f32860b9 100644
--- a/discovery/gossiper_test.go
+++ b/discovery/gossiper_test.go
@@ -897,9 +897,8 @@ func TestProcessAnnouncement(t *testing.T) {
 	}
 }
 
-// TestPrematureAnnouncement checks that premature announcements are
-// not propagated to the router subsystem until block with according
-// block height received.
+// TestPrematureAnnouncement checks that premature announcements are not
+// propagated to the router subsystem.
 func TestPrematureAnnouncement(t *testing.T) {
 	t.Parallel()
 
@@ -920,8 +919,8 @@ func TestPrematureAnnouncement(t *testing.T) {
 
 	// Pretending that we receive the valid channel announcement from
 	// remote side, but block height of this announcement is greater than
-	// highest know to us, for that reason it should be added to the
-	// repeat/premature batch.
+	// highest know to us, for that reason it should be ignored and not
+	// added to the router.
 	ca, err := createRemoteChannelAnnouncement(1)
 	if err != nil {
 		t.Fatalf("can't create channel announcement: %v", err)
@@ -929,31 +928,13 @@ func TestPrematureAnnouncement(t *testing.T) {
 
 	select {
 	case <-ctx.gossiper.ProcessRemoteAnnouncement(ca, nodePeer):
-		t.Fatal("announcement was proceeded")
-	case <-time.After(100 * time.Millisecond):
+	case <-time.After(time.Second):
+		t.Fatal("announcement was not processed")
 	}
 
 	if len(ctx.router.infos) != 0 {
 		t.Fatal("edge was added to router")
 	}
-
-	// Pretending that we receive the valid channel update announcement from
-	// remote side, but block height of this announcement is greater than
-	// highest known to us, so it should be rejected.
-	ua, err := createUpdateAnnouncement(1, 0, remoteKeyPriv1, timestamp)
-	if err != nil {
-		t.Fatalf("can't create update announcement: %v", err)
-	}
-
-	select {
-	case <-ctx.gossiper.ProcessRemoteAnnouncement(ua, nodePeer):
-		t.Fatal("announcement was proceeded")
-	case <-time.After(100 * time.Millisecond):
-	}
-
-	if len(ctx.router.edges) != 0 {
-		t.Fatal("edge update was added to router")
-	}
 }
 
 // TestSignatureAnnouncementLocalFirst ensures that the AuthenticatedGossiper