node: fix setDefaultMinerGasLimit (#19112)

Fix for Issue #18424

Author: yperbasis

execution/protocol/misc/gaslimit_test.go

@@ -0,0 +1,32 @@
+// Copyright 2026 The Erigon Authors
+// This file is part of Erigon.
+//
+// Erigon is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Erigon is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with Erigon. If not, see <http://www.gnu.org/licenses/>.
+
+package misc
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// A test for https://github.com/erigontech/erigon/issues/18424
+func TestCalcGasLimit(t *testing.T) {
+	// https://gnosisscan.io//block/43788389
+	parentGasLimit := uint64(16_999_984)
+	desiredLimit := uint64(17_000_000)
+	gasLimit := CalcGasLimit(parentGasLimit, desiredLimit)
+	assert.Equal(t, desiredLimit, gasLimit)
+}

node/eth/backend.go

@@ -394,8 +394,8 @@ func New(ctx context.Context, stack *node.Node, config *ethconfig.Config, logger
 	backend.genesisBlock = genesis
 	backend.genesisHash = genesis.Hash()
 
-	setDefaultMinerGasLimit(chainConfig, config, logger)
-	setBorDefaultTxPoolPriceLimit(chainConfig, &config.TxPool, logger)
+	setDefaultMinerGasLimit(config, chainConfig)
+	setBorDefaultTxPoolPriceLimit(&config.TxPool, chainConfig, logger)
 
 	logger.Info("Initialised chain configuration", "config", chainConfig, "genesis", genesis.Hash())
 	if dbg.OnlyCreateDB {
@@ -1745,15 +1745,15 @@ func (s *Ethereum) DataDir() string {
 	return s.config.Dirs.DataDir
 }
 
-func setDefaultMinerGasLimit(chainConfig *chain.Config, config *ethconfig.Config, logger log.Logger) {
+func setDefaultMinerGasLimit(config *ethconfig.Config, chainConfig *chain.Config) {
 	if config.Miner.GasLimit == nil {
-		gasLimit := ethconfig.DefaultBlockGasLimitByChain(config)
+		gasLimit := ethconfig.DefaultBlockGasLimitByChain(chainConfig)
 		config.Miner.GasLimit = &gasLimit
 	}
 }
 
 // setBorDefaultTxPoolPriceLimit enforces MinFeeCap to be equal to BorDefaultTxPoolPriceLimit (25gwei by default)
-func setBorDefaultTxPoolPriceLimit(chainConfig *chain.Config, config *txpoolcfg.Config, logger log.Logger) {
+func setBorDefaultTxPoolPriceLimit(config *txpoolcfg.Config, chainConfig *chain.Config, logger log.Logger) {
 	if chainConfig.Bor != nil && config.MinFeeCap != txpoolcfg.BorDefaultTxPoolPriceLimit {
 		logger.Warn("Sanitizing invalid bor min fee cap", "provided", config.MinFeeCap, "updated", txpoolcfg.BorDefaultTxPoolPriceLimit)
 		config.MinFeeCap = txpoolcfg.BorDefaultTxPoolPriceLimit

node/ethconfig/config.go

@@ -53,11 +53,11 @@ var BorDefaultMinerGasPrice = big.NewInt(25 * common.GWei)
 // Fail-back block gas limit. Better specify one in the chain config.
 const DefaultBlockGasLimit uint64 = 60_000_000
 
-func DefaultBlockGasLimitByChain(config *Config) uint64 {
-	if config.Genesis == nil || config.Genesis.Config == nil || config.Genesis.Config.DefaultBlockGasLimit == nil {
+func DefaultBlockGasLimitByChain(chainConfig *chain.Config) uint64 {
+	if chainConfig.DefaultBlockGasLimit == nil {
 		return DefaultBlockGasLimit
 	}
-	return *config.Genesis.Config.DefaultBlockGasLimit
+	return *chainConfig.DefaultBlockGasLimit
 }
 
 // FullNodeGPO contains default gasprice oracle settings for full node.