consensus: return from errors sooner in addVote

consensus/state.go

@@ -1355,7 +1355,10 @@ func (cs *ConsensusState) addVote(vote *types.Vote, peerID p2p.ID) (added bool,
 			return added, ErrVoteHeightMismatch
 		}
 		added, err = cs.LastCommit.AddVote(vote)
-		if added {
+		if !added {
+			return added, err
+		}
+
 		cs.Logger.Info(cmn.Fmt("Added to lastPrecommits: %v", cs.LastCommit.StringShort()))
 		cs.eventBus.PublishEventVote(types.EventDataVote{vote})
 
@@ -1365,16 +1368,25 @@ func (cs *ConsensusState) addVote(vote *types.Vote, peerID p2p.ID) (added bool,
 			// cs.scheduleTimeout(time.Duration(0), cs.Height, 0, cstypes.RoundStepNewHeight)
 			cs.enterNewRound(cs.Height, 0)
 		}
-		}
 
 		return
 	}
 
-	// A prevote/precommit for this height?
+	// Height mismatch is ignored.
-	if vote.Height == cs.Height {
+	// Not necessarily a bad peer, but not favourable behaviour.
+	if vote.Height != cs.Height {
+		err = ErrVoteHeightMismatch
+		cs.Logger.Info("Vote ignored and not added", "voteHeight", vote.Height, "csHeight", cs.Height, "err", err)
+		return
+	}
+
 	height := cs.Height
 	added, err = cs.Votes.AddVote(vote, peerID)
-		if added {
+	if !added {
+		// Either duplicate, or error upon cs.Votes.AddByIndex()
+		return
+	}
+
 	cs.eventBus.PublishEventVote(types.EventDataVote{vote})
 
 	switch vote.Type {
@@ -1449,17 +1461,9 @@ func (cs *ConsensusState) addVote(vote *types.Vote, peerID p2p.ID) (added bool,
 			cs.enterPrecommitWait(height, vote.Round)
 		}
 	default:
-				cmn.PanicSanity(cmn.Fmt("Unexpected vote type %X", vote.Type)) // Should not happen.
+		panic(cmn.Fmt("Unexpected vote type %X", vote.Type)) // go-wire should prevent this.
-			}
-		}
-		// Either duplicate, or error upon cs.Votes.AddByIndex()
-		return
-	} else {
-		err = ErrVoteHeightMismatch
 	}
 
-	// Height mismatch, bad peer?
-	cs.Logger.Info("Vote ignored and not added", "voteHeight", vote.Height, "csHeight", cs.Height, "err", err)
 	return
 }