From e0f82255c7eaa62d87c46ced211167c3a970c568 Mon Sep 17 00:00:00 2001
From: Wilmer Paulino <wilmer.paulino@gmail.com>
Date: Fri, 19 Apr 2019 12:27:33 -0700
Subject: [PATCH] chain: prevent panic if onBlockConnected is called before
 onFilteredBlockConnected

---
 chain/neutrino.go | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/chain/neutrino.go b/chain/neutrino.go
index 38231db..fb109b4 100644
--- a/chain/neutrino.go
+++ b/chain/neutrino.go
@@ -605,19 +605,19 @@ func (s *NeutrinoClient) dispatchRescanFinished() {
 	}
 
 	s.clientMtx.Lock()
-	if bs.Hash != s.lastFilteredBlockHeader.BlockHash() {
-		s.clientMtx.Unlock()
-		return
-	}
-
 	// Only send the RescanFinished notification once.
-	if s.finished {
+	if s.lastFilteredBlockHeader == nil || s.finished {
 		s.clientMtx.Unlock()
 		return
 	}
 
 	// Only send the RescanFinished notification once the underlying chain
 	// service sees itself as current.
+	if bs.Hash != s.lastFilteredBlockHeader.BlockHash() {
+		s.clientMtx.Unlock()
+		return
+	}
+
 	s.finished = s.CS.IsCurrent() && s.lastProgressSent
 	if !s.finished {
 		s.clientMtx.Unlock()