fix: tracing system transactions failed due to wrong state (ethereum#374

)

* fixed wrong state creation which resulted in fail of tracing transaction

* sorted package imports

* added the check to `standardTraceBlockToFile` that resolves the ethereum#314

Co-authored-by: alexqrid <>

eth/state_accessor.go

@@ -19,9 +19,11 @@ package eth
 import (
 	"errors"
 	"fmt"
+	"math/big"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -170,6 +172,14 @@ func (eth *Ethereum) stateAtTransaction(block *types.Block, txIndex int, reexec
 		}
 		// Not yet the searched for transaction, execute on top of the current state
 		vmenv := vm.NewEVM(context, txContext, statedb, eth.blockchain.Config(), vm.Config{})
+		if posa, ok := eth.Engine().(consensus.PoSA); ok && msg.From() == context.Coinbase &&
+			posa.IsSystemContract(msg.To()) && msg.GasPrice().Cmp(big.NewInt(0)) == 0 {
+			balance := statedb.GetBalance(consensus.SystemAddress)
+			if balance.Cmp(common.Big0) > 0 {
+				statedb.SetBalance(consensus.SystemAddress, big.NewInt(0))
+				statedb.AddBalance(context.Coinbase, balance)
+			}
+		}
 		statedb.Prepare(tx.Hash(), block.Hash(), idx)
 		if _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas())); err != nil {
 			return nil, vm.BlockContext{}, nil, fmt.Errorf("transaction %#x failed: %v", tx.Hash(), err)

eth/tracers/api.go

@@ -673,6 +673,15 @@ func (api *API) standardTraceBlockToFile(ctx context.Context, block *types.Block
 		}
 		// Execute the transaction and flush any traces to disk
 		vmenv := vm.NewEVM(vmctx, txContext, statedb, chainConfig, vmConf)
+		if posa, ok := api.backend.Engine().(consensus.PoSA); ok {
+			if isSystem, _ := posa.IsSystemTransaction(tx, block.Header()); isSystem {
+				balance := statedb.GetBalance(consensus.SystemAddress)
+				if balance.Cmp(common.Big0) > 0 {
+					statedb.SetBalance(consensus.SystemAddress, big.NewInt(0))
+					statedb.AddBalance(vmctx.Coinbase, balance)
+				}
+			}
+		}
 		statedb.Prepare(tx.Hash(), block.Hash(), i)
 		_, err = core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(msg.Gas()))
 		if writer != nil {