From ee870396538cb548f26ecc24482b24b4915155d5 Mon Sep 17 00:00:00 2001
From: Maciej Skrzypkowski <mskr@gmx.com>
Date: Thu, 2 Jan 2025 11:06:37 +0100
Subject: [PATCH] Empty blocks built by using calldata

---
 packages/taiko-client/proposer/proposer.go | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/packages/taiko-client/proposer/proposer.go b/packages/taiko-client/proposer/proposer.go
index 411c3ef86be..4d1202a2c31 100644
--- a/packages/taiko-client/proposer/proposer.go
+++ b/packages/taiko-client/proposer/proposer.go
@@ -64,7 +64,7 @@ type Proposer struct {
 	checkProfitability bool
 
 	allowEmptyBlocks bool
-	initDone bool
+	initDone         bool
 }
 
 // InitFromCli initializes the given proposer instance based on the command line flags.
@@ -461,7 +461,7 @@ func (p *Proposer) ProposeTxListOntake(
 		return errors.New("insufficient prover balance")
 	}
 
-	txCandidate, cost, err := p.buildCheaperOnTakeTransaction(ctx, txListsBytesArray)
+	txCandidate, cost, err := p.buildCheaperOnTakeTransaction(ctx, txListsBytesArray, p.isEmptyBlock(txLists))
 	if err != nil {
 		log.Warn("Failed to build TaikoL1.proposeBlocksV2 transaction", "error", encoding.TryParsingCustomError(err))
 		return err
@@ -491,7 +491,7 @@ func (p *Proposer) ProposeTxListOntake(
 }
 
 func (p *Proposer) buildCheaperOnTakeTransaction(ctx context.Context,
-	txListsBytesArray [][]byte) (*txmgr.TxCandidate, *big.Int, error) {
+	txListsBytesArray [][]byte, isEmptyBlock bool) (*txmgr.TxCandidate, *big.Int, error) {
 	txCallData, err := p.txCallDataBuilder.BuildOntake(ctx, txListsBytesArray)
 	if err != nil {
 		return nil, nil, err
@@ -500,7 +500,7 @@ func (p *Proposer) buildCheaperOnTakeTransaction(ctx context.Context,
 	var tx *txmgr.TxCandidate
 	var cost *big.Int
 
-	if p.txBlobBuilder != nil {
+	if p.txBlobBuilder != nil && !isEmptyBlock {
 		txBlob, err := p.txBlobBuilder.BuildOntake(ctx, txListsBytesArray)
 		if err != nil {
 			return nil, nil, err
@@ -521,6 +521,17 @@ func (p *Proposer) buildCheaperOnTakeTransaction(ctx context.Context,
 	return tx, cost, nil
 }
 
+func (p *Proposer) isEmptyBlock(txLists []types.Transactions) bool {
+	for _, txs := range txLists {
+		for _, tx := range txs {
+			if tx.To() != nil {
+				return false
+			}
+		}
+	}
+	return true
+}
+
 func (p *Proposer) chooseCheaperTransaction(
 	txCallData *txmgr.TxCandidate,
 	txBlob *txmgr.TxCandidate,