From 63bfac9740a61aa824e0c9fc29baeffda36d7f2d Mon Sep 17 00:00:00 2001
From: stasatdaglabs <39559713+stasatdaglabs@users.noreply.github.com>
Date: Mon, 18 Nov 2019 14:33:07 +0200
Subject: [PATCH] [NOD-436] Fix sending empty chainChanged messages. (#477)

---
 blockdag/accept.go | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/blockdag/accept.go b/blockdag/accept.go
index fab06e0f1..98e5a689e 100644
--- a/blockdag/accept.go
+++ b/blockdag/accept.go
@@ -97,10 +97,12 @@ func (dag *BlockDAG) maybeAcceptBlock(block *util.Block, flags BehaviorFlags) er
 		Block:         block,
 		WasUnorphaned: flags&BFWasUnorphaned != 0,
 	})
-	dag.sendNotification(NTChainChanged, &ChainChangedNotificationData{
-		RemovedChainBlockHashes: chainUpdates.removedChainBlockHashes,
-		AddedChainBlockHashes:   chainUpdates.addedChainBlockHashes,
-	})
+	if len(chainUpdates.removedChainBlockHashes) > 0 || len(chainUpdates.addedChainBlockHashes) > 0 {
+		dag.sendNotification(NTChainChanged, &ChainChangedNotificationData{
+			RemovedChainBlockHashes: chainUpdates.removedChainBlockHashes,
+			AddedChainBlockHashes:   chainUpdates.addedChainBlockHashes,
+		})
+	}
 	dag.dagLock.Lock()
 
 	return nil