From 8358ba8974a94769af1f2faa6678a37236bf4859 Mon Sep 17 00:00:00 2001
From: setunapo <setunapo@outlook.kr>
Date: Wed, 31 May 2023 09:24:12 +0800
Subject: [PATCH] fix: remove naturally finality

detail refer: https://github.com/bnb-chain/bsc/pull/1651
---
 consensus/parlia/parlia.go   | 22 +++-------------------
 consensus/parlia/snapshot.go | 10 +++++-----
 core/types/vote.go           |  1 -
 3 files changed, 8 insertions(+), 25 deletions(-)

diff --git a/consensus/parlia/parlia.go b/consensus/parlia/parlia.go
index 9765d9f5714..31b6209ebef 100644
--- a/consensus/parlia/parlia.go
+++ b/consensus/parlia/parlia.go
@@ -1617,19 +1617,13 @@ func (p *Parlia) GetJustifiedNumberAndHash(chain consensus.ChainHeaderReader, he
 }
 
 // GetFinalizedHeader returns highest finalized block header.
-// It will find vote finalized block within NaturallyFinalizedDist blocks firstly,
-// If the vote finalized block not found, return its naturally finalized block.
 func (p *Parlia) GetFinalizedHeader(chain consensus.ChainHeaderReader, header *types.Header) *types.Header {
-	backward := uint64(types.NaturallyFinalizedDist)
 	if chain == nil || header == nil {
 		return nil
 	}
 	if !chain.Config().IsPlato(header.Number.Uint64()) {
 		return chain.GetHeaderByNumber(0)
 	}
-	if header.Number.Uint64() < backward {
-		backward = header.Number.Uint64()
-	}
 
 	snap, err := p.snapshot(chain, header.Number.Uint64(), header.Hash(), nil, true)
 	if err != nil {
@@ -1638,18 +1632,8 @@ func (p *Parlia) GetFinalizedHeader(chain consensus.ChainHeaderReader, header *t
 		return nil
 	}
 
-	for snap.Attestation != nil && snap.Attestation.SourceNumber >= header.Number.Uint64()-backward {
-		if snap.Attestation.TargetNumber == snap.Attestation.SourceNumber+1 {
-			return chain.GetHeaderByHash(snap.Attestation.SourceHash)
-		}
-
-		snap, err = p.snapshot(chain, snap.Attestation.SourceNumber, snap.Attestation.SourceHash, nil, true)
-		if err != nil {
-			log.Error("GetFinalizedHeader snapshot",
-				"error", err, "SourceNumber", snap.Attestation.SourceNumber, "SourceHash", snap.Attestation.SourceHash)
-			return nil
-		}
+	if snap.Attestation != nil {
+		return chain.GetHeader(snap.Attestation.SourceHash, snap.Attestation.SourceNumber)
 	}
-
-	return FindAncientHeader(header, backward, chain, nil)
+	return nil
 }
diff --git a/consensus/parlia/snapshot.go b/consensus/parlia/snapshot.go
index 29007ef2b93..94272822709 100644
--- a/consensus/parlia/snapshot.go
+++ b/consensus/parlia/snapshot.go
@@ -215,11 +215,11 @@ func (s *Snapshot) updateAttestation(header *types.Header, chainConfig *chain.Co
 	}
 
 	// Update attestation
-	s.Attestation = &types.VoteData{
-		SourceNumber: attestation.Data.SourceNumber,
-		SourceHash:   attestation.Data.SourceHash,
-		TargetNumber: attestation.Data.TargetNumber,
-		TargetHash:   attestation.Data.TargetHash,
+	if s.Attestation != nil && attestation.Data.SourceNumber+1 != attestation.Data.TargetNumber {
+		s.Attestation.TargetNumber = attestation.Data.TargetNumber
+		s.Attestation.TargetHash = attestation.Data.TargetHash
+	} else {
+		s.Attestation = attestation.Data
 	}
 }
 
diff --git a/core/types/vote.go b/core/types/vote.go
index 8c4882243ce..3533b220c78 100644
--- a/core/types/vote.go
+++ b/core/types/vote.go
@@ -13,7 +13,6 @@ const (
 	BLSSignatureLength = 96
 
 	MaxAttestationExtraLength = 256
-	NaturallyFinalizedDist    = 21 // The distance to naturally finalized a block
 )
 
 type BLSPublicKey [BLSPublicKeyLength]byte