From 216409ed060c071ae75c53a169e2a40b168684c4 Mon Sep 17 00:00:00 2001
From: shantichanal <158101918+shantichanal@users.noreply.github.com>
Date: Tue, 29 Jul 2025 13:12:31 +0200
Subject: [PATCH] fixed td and accumulator behaviour

---
 cmd/utils/flags.go              | 11 ++++++-----
 internal/era/execdb/builder.go  | 29 +++++++++++++++++++----------
 internal/era/execdb/era_test.go |  2 +-
 3 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 3dd619e80a..b10f6ebd52 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -114,11 +114,6 @@ var (
 		Usage:    "Root directory for era1 history (default = inside ancient/chain)",
 		Category: flags.EthCategory,
 	}
-	EraFormatFlag = &cli.StringFlag{
-		Name:     "eraformat",
-		Usage:    "Archive format: 'era1' or 'erae'",
-		Category: flags.EthCategory,
-	}
 	MinFreeDiskSpaceFlag = &cli.IntFlag{
 		Name:     "datadir.minfreedisk",
 		Usage:    "Minimum free disk space in MB, once reached triggers auto shut down (default = --cache.gc converted to MB, 0 = disabled)",
@@ -1041,6 +1036,12 @@ Please note that --` + MetricsHTTPFlag.Name + ` must be set to start the server.
 		Value:    metrics.DefaultConfig.InfluxDBOrganization,
 		Category: flags.MetricsCategory,
 	}
+
+	// Era flags are a group of flags related to the era archive format.
+	EraFormatFlag = &cli.StringFlag{
+		Name:  "era.format",
+		Usage: "Archive format: 'era1' or 'erae'",
+	}
 )
 
 var (
diff --git a/internal/era/execdb/builder.go b/internal/era/execdb/builder.go
index 101e09cd56..047986a17c 100644
--- a/internal/era/execdb/builder.go
+++ b/internal/era/execdb/builder.go
@@ -51,11 +51,9 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/history"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/internal/era"
 	"github.com/ethereum/go-ethereum/internal/era/e2store"
-	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/golang/snappy"
 )
@@ -90,6 +88,9 @@ type Builder struct {
 	startNum      *uint64
 	written       uint64
 	expectsProofs bool
+	isPreMerge    bool
+	numPreMerge   int      // number of pre-merge blocks
+	finalTD       *big.Int // final total difficulty, used for pre-merge and merge straddling files
 }
 
 // NewBuilder returns a new Builder instance.
@@ -151,19 +152,27 @@ func (b *Builder) AddRLP(headerRLP []byte, bodyRLP []byte, receipts []byte, proo
 	if len(b.buff.headers) >= era.MaxSize {
 		return fmt.Errorf("exceeds max size %d", era.MaxSize)
 	}
+	if len(b.buff.headers) == 0 && td != nil {
+		if td.Sign() > 0 {
+			b.isPreMerge = true
+		}
+	}
 
 	b.buff.headers = append(b.buff.headers, headerRLP)
 	b.buff.bodies = append(b.buff.bodies, bodyRLP)
 	b.buff.receipts = append(b.buff.receipts, receipts)
-	b.buff.tds = append(b.buff.tds, new(big.Int).Set(td))
-	b.hashes = append(b.hashes, blockHash)
-	if proof != nil {
-		b.buff.proofs = append(b.buff.proofs, proof)
+	if td != nil {
+		if b.isPreMerge && td.Sign() > 0 {
+			b.buff.tds = append(b.buff.tds, new(big.Int).Set(td))
+			b.finalTD = new(big.Int).Set(td)
+			b.hashes = append(b.hashes, blockHash)
+		} else if b.isPreMerge {
+			b.buff.tds = append(b.buff.tds, new(big.Int).Set(b.finalTD))
+		}
 	}
 
-	mergeblock := history.PrunePoints[params.MainnetGenesisHash]
-	if mergeblock != nil && blockNum <= mergeblock.BlockNumber {
-		b.buff.tds = append(b.buff.tds, new(big.Int).Set(td))
+	if proof != nil {
+		b.buff.proofs = append(b.buff.proofs, proof)
 	}
 
 	// Write Era2 version before writing any blocks.
@@ -233,7 +242,7 @@ func (b *Builder) Finalize() (common.Hash, error) {
 	var accRoot common.Hash
 	if len(b.hashes) > 0 {
 		var err error
-		accRoot, err = era.ComputeAccumulator(b.hashes, b.buff.tds)
+		accRoot, err = era.ComputeAccumulator(b.hashes, b.buff.tds[:len(b.hashes)])
 		if err != nil {
 			return common.Hash{}, fmt.Errorf("compute accumulator: %w", err)
 		}
diff --git a/internal/era/execdb/era_test.go b/internal/era/execdb/era_test.go
index f9ccc35254..a841820e15 100644
--- a/internal/era/execdb/era_test.go
+++ b/internal/era/execdb/era_test.go
@@ -54,7 +54,7 @@ func TestEra2Builder(t *testing.T) {
 		chain.headers = append(chain.headers, types.Header{Number: big.NewInt(int64(i))})
 		chain.bodies = append(chain.bodies, types.Body{Transactions: []*types.Transaction{types.NewTransaction(0, common.Address{byte(i)}, nil, 0, nil, nil)}})
 		chain.receipts = append(chain.receipts, types.Receipts{{CumulativeGasUsed: uint64(i)}})
-		chain.tds = append(chain.tds, big.NewInt(int64(i)))
+		chain.tds = append(chain.tds, big.NewInt(int64(i+1)))
 	}
 
 	// Write blocks to Era1.