From df9ef1e7339b41f54e53e1bc2aeee0a5a24646d5 Mon Sep 17 00:00:00 2001
From: Ethan Buchman <ethan@coinculture.info>
Date: Mon, 19 Oct 2015 12:34:53 -0400
Subject: [PATCH] check peerMempoolChan for nil on Reset

---
 mempool/reactor.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/mempool/reactor.go b/mempool/reactor.go
index 1101afa4b..a1f61a4c5 100644
--- a/mempool/reactor.go
+++ b/mempool/reactor.go
@@ -97,7 +97,12 @@ func (memR *MempoolReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte) {
 func (memR *MempoolReactor) ResetForBlockAndState(block *types.Block, state *sm.State) {
 	ri := memR.Mempool.ResetForBlockAndState(block, state)
 	for _, peer := range memR.Switch.Peers().List() {
-		peerMempoolCh := peer.Data.Get(types.PeerMempoolChKey).(chan ResetInfo)
+		peerMempoolChI := peer.Data.Get(types.PeerMempoolChKey)
+		if peerMempoolChI == nil {
+			// peer was added to switch but not yet to the memR
+			continue
+		}
+		peerMempoolCh := peerMempoolChI.(chan ResetInfo)
 		select {
 		case peerMempoolCh <- ri:
 		default: