improve: drop dumplicate votes when assembling attestation

consensus/parlia/parlia.go

@@ -868,8 +868,9 @@ func (p *Parlia) assembleVoteAttestation(chain consensus.ChainHeaderReader, head
  voteAddrSet := make(map[types.BLSPublicKey]struct{}, len(votes))
  signatures := make([][]byte, 0, len(votes))
  for _, vote := range votes {
+ // In some corner case, one vote may be included twice.
  if _, ok := voteAddrSet[vote.VoteAddress]; ok {
- return fmt.Errorf("assemble VoteAttestation failed, double sign by %s", common.Bytes2Hex(vote.VoteAddress[:]))
+ continue
  }
  voteAddrSet[vote.VoteAddress] = struct{}{}
  signatures = append(signatures, vote.Signature[:])
@@ -885,8 +886,7 @@ func (p *Parlia) assembleVoteAttestation(chain consensus.ChainHeaderReader, head
  attestation.VoteAddressSet |= 1 << (valInfo.Index - 1) //Index is offset by 1
  }
  }
- // The valid voted validators should be no less than 2/3 validators,
- // In some corner case, one vote may be included twice, so here need check again.
+ // The valid voted validators should be no less than 2/3 validators.
  validatorsBitSet := bitset.From([]uint64{uint64(attestation.VoteAddressSet)})
  if validatorsBitSet.Count() < uint(cmath.CeilDiv(len(snap.Validators)*2, 3)) {
  return fmt.Errorf("invalid attestation, not enough validators voted")