From e3a8b3b0c447e48cf57f738c6022cfddc2336f90 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@lightning.engineering>
Date: Thu, 19 Dec 2019 18:10:02 -0800
Subject: [PATCH] routing/router: prune zombies when either end is stale

---
 routing/router.go | 31 ++++++++++++-------------------
 1 file changed, 12 insertions(+), 19 deletions(-)

diff --git a/routing/router.go b/routing/router.go
index 243bde49..25ce4994 100644
--- a/routing/router.go
+++ b/routing/router.go
@@ -824,30 +824,23 @@ func (r *ChannelRouter) pruneZombieChans() error {
 			return nil
 		}
 
-		// If *both* edges haven't been updated for a period of
+		// If either edge hasn't been updated for a period of
 		// chanExpiry, then we'll mark the channel itself as eligible
 		// for graph pruning.
-		var e1Zombie, e2Zombie bool
-		if e1 != nil {
-			e1Zombie = time.Since(e1.LastUpdate) >= chanExpiry
-			if e1Zombie {
-				log.Tracef("Edge #1 of ChannelID(%v) last "+
-					"update: %v", info.ChannelID,
-					e1.LastUpdate)
-			}
+		e1Zombie := e1 == nil || time.Since(e1.LastUpdate) >= chanExpiry
+		e2Zombie := e2 == nil || time.Since(e2.LastUpdate) >= chanExpiry
+
+		if e1Zombie {
+			log.Tracef("Node1 pubkey=%x of chan_id=%v is zombie",
+				info.NodeKey1Bytes, info.ChannelID)
 		}
-		if e2 != nil {
-			e2Zombie = time.Since(e2.LastUpdate) >= chanExpiry
-			if e2Zombie {
-				log.Tracef("Edge #2 of ChannelID(%v) last "+
-					"update: %v", info.ChannelID,
-					e2.LastUpdate)
-			}
+		if e2Zombie {
+			log.Tracef("Node2 pubkey=%x of chan_id=%v is zombie",
+				info.NodeKey2Bytes, info.ChannelID)
 		}
 
-		// If the channel is not considered zombie, we can move on to
-		// the next.
-		if !e1Zombie || !e2Zombie {
+		// Return early if both sides have a recent update.
+		if !e1Zombie && !e2Zombie {
 			return nil
 		}