From 9af2d97deb4386f124065893b6ca11400d17d882 Mon Sep 17 00:00:00 2001
From: Mateusz Morusiewicz <11313015+Ruteri@users.noreply.github.com>
Date: Tue, 11 Oct 2022 16:34:36 +0200
Subject: [PATCH] Do not commit failing payment txs (#43)

---
 miner/algo_common.go      | 45 ++++++++++++++++++++++++---------------
 miner/algo_common_test.go |  8 +++++--
 2 files changed, 34 insertions(+), 19 deletions(-)

diff --git a/miner/algo_common.go b/miner/algo_common.go
index 9c399936126b..90f4b2a79eb4 100644
--- a/miner/algo_common.go
+++ b/miner/algo_common.go
@@ -293,25 +293,24 @@ func estimatePayoutTxGas(env *environment, sender, receiver common.Address, prv
 }
 
 func insertPayoutTx(env *environment, sender, receiver common.Address, gas uint64, isEOA bool, availableFunds *big.Int, prv *ecdsa.PrivateKey, chData chainData) (*types.Receipt, error) {
-	diff := newEnvironmentDiff(env)
-	applyTx := func(gas uint64) (*types.Receipt, error) {
+	applyTx := func(envDiff *environmentDiff, gas uint64) (*types.Receipt, error) {
 		fee := new(big.Int).Mul(env.header.BaseFee, new(big.Int).SetUint64(gas))
 		amount := new(big.Int).Sub(availableFunds, fee)
 		if amount.Sign() < 0 {
 			return nil, errors.New("not enough funds available")
 		}
-		rec, err := diff.commitPayoutTx(amount, sender, receiver, gas, prv, chData)
+		rec, err := envDiff.commitPayoutTx(amount, sender, receiver, gas, prv, chData)
 		if err != nil {
 			return nil, fmt.Errorf("failed to commit payment tx: %w", err)
-		}
-		if rec.Status != types.ReceiptStatusSuccessful {
+		} else if rec.Status != types.ReceiptStatusSuccessful {
 			return nil, fmt.Errorf("payment tx failed")
 		}
 		return rec, nil
 	}
 
 	if isEOA {
-		rec, err := applyTx(gas)
+		diff := newEnvironmentDiff(env)
+		rec, err := applyTx(diff, gas)
 		if err != nil {
 			return nil, err
 		}
@@ -319,24 +318,36 @@ func insertPayoutTx(env *environment, sender, receiver common.Address, gas uint6
 		return rec, nil
 	}
 
-	var (
-		rec *types.Receipt
-		err error
-	)
+	var err error
 	for i := 0; i < 6; i++ {
-		rec, err = applyTx(gas)
+		diff := newEnvironmentDiff(env)
+		var rec *types.Receipt
+		rec, err = applyTx(diff, gas)
 		if err != nil {
 			gas += 1000
-		} else {
-			break
+			continue
+		}
+
+		if gas == rec.GasUsed {
+			diff.applyToBaseEnv()
+			return rec, nil
+		}
+
+		exactEnvDiff := newEnvironmentDiff(env)
+		exactRec, err := applyTx(exactEnvDiff, rec.GasUsed)
+		if err != nil {
+			diff.applyToBaseEnv()
+			return rec, nil
 		}
+		exactEnvDiff.applyToBaseEnv()
+		return exactRec, nil
 	}
 
-	if err != nil {
-		return nil, err
+	if err == nil {
+		return nil, errors.New("could not estimate gas")
 	}
-	diff.applyToBaseEnv()
-	return rec, nil
+
+	return nil, err
 }
 
 func (envDiff *environmentDiff) commitPayoutTx(amount *big.Int, sender, receiver common.Address, gas uint64, prv *ecdsa.PrivateKey, chData chainData) (*types.Receipt, error) {
diff --git a/miner/algo_common_test.go b/miner/algo_common_test.go
index b94198608f4e..84fd4a935762 100644
--- a/miner/algo_common_test.go
+++ b/miner/algo_common_test.go
@@ -548,6 +548,7 @@ func TestPayoutTxUtils(t *testing.T) {
 	require.Equal(t, types.ReceiptStatusSuccessful, rec.Status)
 	require.Equal(t, uint64(21000), rec.GasUsed)
 	require.True(t, new(big.Int).Sub(balanceAfter, balanceBefore).Cmp(expectedPayment) == 0)
+	require.Equal(t, env.state.GetNonce(signers.addresses[1]), uint64(1))
 
 	// Sending payment to the contract that logs event of the amount
 	gas, isEOA, err = estimatePayoutTxGas(env, signers.addresses[1], logContractAddress, signers.signers[1], chData)
@@ -564,10 +565,10 @@ func TestPayoutTxUtils(t *testing.T) {
 	require.Equal(t, types.ReceiptStatusSuccessful, rec.Status)
 	require.Equal(t, uint64(22025), rec.GasUsed)
 	require.True(t, new(big.Int).Sub(balanceAfter, balanceBefore).Cmp(expectedPayment) == 0)
+	require.Equal(t, env.state.GetNonce(signers.addresses[1]), uint64(2))
 
 	// Try requesting less gas for contract tx. We request 21k gas, but we must pay 22025
-	// iteration logic should set gas limit to 23k
-	expectedPayment = new(big.Int).Sub(availableFunds, big.NewInt(23000))
+	expectedPayment = new(big.Int).Sub(availableFunds, big.NewInt(22025))
 	balanceBefore = env.state.GetBalance(logContractAddress)
 	rec, err = insertPayoutTx(env, signers.addresses[1], logContractAddress, 21000, isEOA, availableFunds, signers.signers[1], chData)
 	balanceAfter = env.state.GetBalance(logContractAddress)
@@ -576,6 +577,7 @@ func TestPayoutTxUtils(t *testing.T) {
 	require.Equal(t, types.ReceiptStatusSuccessful, rec.Status)
 	require.Equal(t, uint64(22025), rec.GasUsed)
 	require.True(t, new(big.Int).Sub(balanceAfter, balanceBefore).Cmp(expectedPayment) == 0)
+	require.Equal(t, env.state.GetNonce(signers.addresses[1]), uint64(3))
 
 	// errors
 
@@ -591,4 +593,6 @@ func TestPayoutTxUtils(t *testing.T) {
 
 	_, err = insertPayoutTx(env, signers.addresses[1], signers.addresses[2], 20000, true, availableFunds, signers.signers[1], chData)
 	require.ErrorContains(t, err, "not enough gas")
+
+	require.Equal(t, env.state.GetNonce(signers.addresses[1]), uint64(3))
 }