From 4b4980d949d33c2efa60866dd715ade32d89469c Mon Sep 17 00:00:00 2001
From: Daniel Liu <139250065@qq.com>
Date: Thu, 17 Jul 2025 17:54:23 +0800
Subject: [PATCH] core/vm: set basefee to 0 internally on eth_call #28470
 (#1238)

---
 core/state_transition.go |  4 +++-
 core/vm/evm.go           | 18 ++++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/core/state_transition.go b/core/state_transition.go
index 3c829f7983..854ce14cec 100644
--- a/core/state_transition.go
+++ b/core/state_transition.go
@@ -271,10 +271,12 @@ func (st *StateTransition) preCheck() error {
 				msg.From().Hex(), codeHash)
 		}
 	}
+
 	// Make sure that transaction gasFeeCap is greater than the baseFee (post london)
 	if st.evm.ChainConfig().IsEIP1559(st.evm.Context.BlockNumber) {
 		// Skip the checks if gas fields are zero and baseFee was explicitly disabled (eth_call)
-		if !st.evm.Config.NoBaseFee || st.gasFeeCap.BitLen() > 0 || st.gasTipCap.BitLen() > 0 {
+		skipCheck := st.evm.Config.NoBaseFee && st.gasFeeCap.BitLen() == 0 && st.gasTipCap.BitLen() == 0
+		if !skipCheck {
 			if l := st.gasFeeCap.BitLen(); l > 256 {
 				return fmt.Errorf("%w: address %v, maxFeePerGas bit length: %d", ErrFeeCapVeryHigh,
 					msg.From().Hex(), l)
diff --git a/core/vm/evm.go b/core/vm/evm.go
index e5461e7b8e..1b1283dba0 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -74,7 +74,7 @@ type BlockContext struct {
 	BlockNumber *big.Int       // Provides information for NUMBER
 	Time        *big.Int       // Provides information for TIME
 	Difficulty  *big.Int       // Provides information for DIFFICULTY
-	BaseFee     *big.Int       // Provides information for BASEFEE
+	BaseFee     *big.Int       // Provides information for BASEFEE (0 if vm runs with NoBaseFee flag and 0 gas price)
 	Random      *common.Hash   // Provides information for PREVRANDAO
 }
 
@@ -83,7 +83,7 @@ type BlockContext struct {
 type TxContext struct {
 	// Message information
 	Origin   common.Address // Provides information for ORIGIN
-	GasPrice *big.Int       // Provides information for GASPRICE
+	GasPrice *big.Int       // Provides information for GASPRICE (and is used to zero the basefee if NoBaseFee is set)
 }
 
 // EVM is the Ethereum Virtual Machine base object and provides
@@ -128,6 +128,14 @@ type EVM struct {
 // NewEVM returns a new EVM. The returned EVM is not thread safe and should
 // only ever be used *once*.
 func NewEVM(blockCtx BlockContext, txCtx TxContext, statedb StateDB, tradingStateDB *tradingstate.TradingStateDB, chainConfig *params.ChainConfig, config Config) *EVM {
+	// If basefee tracking is disabled (eth_call, eth_estimateGas, etc), and no
+	// gas prices were specified, lower the basefee to 0 to avoid breaking EVM
+	// invariants (basefee < feecap)
+	if config.NoBaseFee {
+		if txCtx.GasPrice.BitLen() == 0 {
+			blockCtx.BaseFee = new(big.Int)
+		}
+	}
 	evm := &EVM{
 		Context:        blockCtx,
 		TxContext:      txCtx,
@@ -165,12 +173,6 @@ func (evm *EVM) Interpreter() *EVMInterpreter {
 	return evm.interpreter
 }
 
-// SetBlockContext updates the block context of the EVM.
-func (evm *EVM) SetBlockContext(blockCtx BlockContext) {
-	evm.Context = blockCtx
-	evm.chainRules = evm.chainConfig.Rules(blockCtx.BlockNumber)
-}
-
 // Call executes the contract associated with the addr with the given input as
 // parameters. It also handles any necessary value transfer required and takes
 // the necessary steps to create accounts and reverses the state in case of an