From b0d8f552c505ae0adc5a8fe22525af31b9a71081 Mon Sep 17 00:00:00 2001
From: Anton Kaliaev <anton.kalyaev@gmail.com>
Date: Mon, 5 Mar 2018 15:35:50 +0400
Subject: [PATCH] return err if peer has sent a vote that does not match our
 round

---
 consensus/types/height_vote_set.go      | 11 +++++++----
 consensus/types/height_vote_set_test.go |  4 ++--
 types/vote.go                           |  2 +-
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/consensus/types/height_vote_set.go b/consensus/types/height_vote_set.go
index 7db932045..a155bce08 100644
--- a/consensus/types/height_vote_set.go
+++ b/consensus/types/height_vote_set.go
@@ -1,6 +1,7 @@
 package types
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 	"sync"
@@ -15,6 +16,10 @@ type RoundVoteSet struct {
 	Precommits *types.VoteSet
 }
 
+var (
+	GotVoteFromUnwantedRoundError = errors.New("Peer has sent a vote that does not match our round for more than one round")
+)
+
 /*
 Keeps track of all VoteSets from round 0 to round 'round'.
 
@@ -117,10 +122,8 @@ func (hvs *HeightVoteSet) AddVote(vote *types.Vote, peerID p2p.ID) (added bool,
 			voteSet = hvs.getVoteSet(vote.Round, vote.Type)
 			hvs.peerCatchupRounds[peerID] = append(rndz, vote.Round)
 		} else {
-			// Peer has sent a vote that does not match our round,
-			// for more than one round.  Bad peer!
-			// TODO punish peer.
-			// log.Warn("Deal with peer giving votes from unwanted rounds")
+			// punish peer
+			err = GotVoteFromUnwantedRoundError
 			return
 		}
 	}
diff --git a/consensus/types/height_vote_set_test.go b/consensus/types/height_vote_set_test.go
index 5719d7eea..246c0b711 100644
--- a/consensus/types/height_vote_set_test.go
+++ b/consensus/types/height_vote_set_test.go
@@ -34,8 +34,8 @@ func TestPeerCatchupRounds(t *testing.T) {
 
 	vote1001_0 := makeVoteHR(t, 1, 1001, privVals, 0)
 	added, err = hvs.AddVote(vote1001_0, "peer1")
-	if err != nil {
-		t.Error("AddVote error", err)
+	if err != GotVoteFromUnwantedRoundError {
+		t.Errorf("Expected GotVoteFromUnwantedRoundError, but got %v", err)
 	}
 	if added {
 		t.Error("Expected to *not* add vote from peer, too many catchup rounds.")
diff --git a/types/vote.go b/types/vote.go
index 6b36e0f4f..ceb6e985e 100644
--- a/types/vote.go
+++ b/types/vote.go
@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/tendermint/go-crypto"
+	crypto "github.com/tendermint/go-crypto"
 	"github.com/tendermint/tendermint/wire"
 	cmn "github.com/tendermint/tmlibs/common"
 )