e2e: clean up generation of evidence (#6904)

internal/evidence/pool.go

@@ -516,10 +516,13 @@ func (evpool *Pool) processConsensusBuffer(state sm.State) {
 
 		// Check the height of the conflicting votes and fetch the corresponding time and validator set
 		// to produce the valid evidence
-		var dve *types.DuplicateVoteEvidence
+		var (
+			dve *types.DuplicateVoteEvidence
+			err error
+		)
 		switch {
 		case voteSet.VoteA.Height == state.LastBlockHeight:
-			dve = types.NewDuplicateVoteEvidence(
+			dve, err = types.NewDuplicateVoteEvidence(
 				voteSet.VoteA,
 				voteSet.VoteB,
 				state.LastBlockTime,
@@ -527,8 +530,8 @@ func (evpool *Pool) processConsensusBuffer(state sm.State) {
 			)
 
 		case voteSet.VoteA.Height < state.LastBlockHeight:
-			valSet, err := evpool.stateDB.LoadValidators(voteSet.VoteA.Height)
-			if err != nil {
+			valSet, dbErr := evpool.stateDB.LoadValidators(voteSet.VoteA.Height)
+			if dbErr != nil {
 				evpool.logger.Error("failed to load validator set for conflicting votes",
 					"height", voteSet.VoteA.Height, "err", err)
 				continue
@@ -538,7 +541,7 @@ func (evpool *Pool) processConsensusBuffer(state sm.State) {
 				evpool.logger.Error("failed to load block time for conflicting votes", "height", voteSet.VoteA.Height)
 				continue
 			}
-			dve = types.NewDuplicateVoteEvidence(
+			dve, err = types.NewDuplicateVoteEvidence(
 				voteSet.VoteA,
 				voteSet.VoteB,
 				blockMeta.Header.Time,
@@ -554,6 +557,10 @@ func (evpool *Pool) processConsensusBuffer(state sm.State) {
 				"state.LastBlockHeight", state.LastBlockHeight)
 			continue
 		}
+		if err != nil {
+			evpool.logger.Error("error in generating evidence from votes", "err", err)
+			continue
+		}
 
 		// check if we already have this evidence
 		if evpool.isPending(dve) {

internal/evidence/reactor_test.go

@@ -534,12 +534,13 @@ func TestEvidenceListSerialization(t *testing.T) {
 
 	valSet := types.NewValidatorSet([]*types.Validator{val})
 
-	dupl := types.NewDuplicateVoteEvidence(
+	dupl, err := types.NewDuplicateVoteEvidence(
 		exampleVote(1),
 		exampleVote(2),
 		defaultEvidenceTime,
 		valSet,
 	)
+	require.NoError(t, err)
 
 	testCases := map[string]struct {
 		evidenceList []types.Evidence