evm, rpc: disable BaseFee for non London block (#662)

* disable basefee if not london block

* add london block check in state transition

* fix linter

* add unit test

* clean code

* add changelog

x/evm/keeper/state_transition.go

@@ -159,7 +159,10 @@ func (k *Keeper) ApplyTransaction(tx *ethtypes.Transaction) (*types.MsgEthereumT
 	// get the latest signer according to the chain rules from the config
 	signer := ethtypes.MakeSigner(ethCfg, big.NewInt(ctx.BlockHeight()))
 
-	baseFee := k.feeMarketKeeper.GetBaseFee(ctx)
+	var baseFee *big.Int
+	if types.IsLondon(ethCfg, ctx.BlockHeight()) {
+		baseFee = k.feeMarketKeeper.GetBaseFee(ctx)
+	}
 
 	msg, err := tx.AsMessage(signer, baseFee)
 	if err != nil {
@@ -368,7 +371,10 @@ func (k *Keeper) ApplyNativeMessage(msg core.Message) (*types.MsgEthereumTxRespo
 		return nil, stacktrace.Propagate(err, "failed to obtain coinbase address")
 	}
 
-	baseFee := k.feeMarketKeeper.GetBaseFee(ctx)
+	var baseFee *big.Int
+	if types.IsLondon(ethCfg, ctx.BlockHeight()) {
+		baseFee = k.feeMarketKeeper.GetBaseFee(ctx)
+	}
 
 	tracer := types.NewTracer(k.tracer, msg, ethCfg, ctx.BlockHeight(), k.debug)
 	evm := k.NewEVM(msg, ethCfg, params, coinbase, baseFee, tracer)

x/evm/types/params.go

@@ -2,6 +2,9 @@ package types
 
 import (
 	"fmt"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/params"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	paramtypes "github.com/cosmos/cosmos-sdk/x/params/types"
@@ -132,3 +135,8 @@ func validateChainConfig(i interface{}) error {
 
 	return cfg.Validate()
 }
+
+func IsLondon(ethConfig *params.ChainConfig, height int64) bool {
+	rules := ethConfig.Rules(big.NewInt(height))
+	return rules.IsLondon
+}

x/evm/types/params_test.go

@@ -3,6 +3,8 @@ package types
 import (
 	"testing"
 
+	"github.com/ethereum/go-ethereum/params"
+
 	paramtypes "github.com/cosmos/cosmos-sdk/x/params/types"
 	"github.com/stretchr/testify/require"
 )
@@ -104,3 +106,32 @@ func TestValidateChainConfig(t *testing.T) {
 		}
 	}
 }
+
+func TestIsLondon(t *testing.T) {
+	testCases := []struct {
+		name   string
+		height int64
+		result bool
+	}{
+		{
+			"Before london block",
+			5,
+			false,
+		},
+		{
+			"After london block",
+			12_965_001,
+			true,
+		},
+		{
+			"london block",
+			12_965_000,
+			true,
+		},
+	}
+
+	for _, tc := range testCases {
+		ethConfig := params.MainnetChainConfig
+		require.Equal(t, IsLondon(ethConfig, tc.height), tc.result)
+	}
+}