From c6a648fad74179ddd8bae8cd8da705b4c51e6ea5 Mon Sep 17 00:00:00 2001
From: Ethan Buchman <ethan@coinculture.info>
Date: Wed, 16 Nov 2016 16:47:31 -0500
Subject: [PATCH] consensus: lock before loading commit

---
 consensus/reactor.go | 7 +------
 consensus/state.go   | 9 +++++++++
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/consensus/reactor.go b/consensus/reactor.go
index 0ece82ce1..60d5a8f5d 100644
--- a/consensus/reactor.go
+++ b/consensus/reactor.go
@@ -658,12 +658,7 @@ OUTER_LOOP:
 		{
 			prs := ps.GetRoundState()
 			if prs.CatchupCommitRound != -1 && 0 < prs.Height && prs.Height <= conR.conS.blockStore.Height() {
-				var commit *types.Commit
-				if prs.Height == conR.conS.blockStore.Height() {
-					commit = conR.conS.blockStore.LoadSeenCommit(prs.Height)
-				} else {
-					commit = conR.conS.blockStore.LoadBlockCommit(prs.Height)
-				}
+				commit := conR.conS.LoadCommit(prs.Height)
 				peer.TrySend(StateChannel, struct{ ConsensusMessage }{&VoteSetMaj23Message{
 					Height:  prs.Height,
 					Round:   commit.Round(),
diff --git a/consensus/state.go b/consensus/state.go
index 59bea2315..85d4d1679 100644
--- a/consensus/state.go
+++ b/consensus/state.go
@@ -319,6 +319,15 @@ func (cs *ConsensusState) SetPrivValidator(priv PrivValidator) {
 	cs.privValidator = priv
 }
 
+func (cs *ConsensusState) LoadCommit(height int) *types.Commit {
+	cs.mtx.Lock()
+	defer cs.mtx.Unlock()
+	if height == cs.blockStore.Height() {
+		return cs.blockStore.LoadSeenCommit(height)
+	}
+	return cs.blockStore.LoadBlockCommit(height)
+}
+
 func (cs *ConsensusState) OnStart() error {
 	cs.BaseService.OnStart()