problem: chainid should be allowed to be 0 (zero-value), but not nil

solution: don't check against 0 in ChainConfig.GetChainID uses and simplify ChainIdSigner.Equal

core/config_test.go

@@ -435,12 +435,19 @@ func TestChainConfig_GetSigner(t *testing.T) {
 func TestChainConfig_GetChainID(t *testing.T) {
 	d := DefaultConfig
 	cid := d.GetChainID()
+	// check is not zero
 	if cid.Cmp(new(big.Int)) == 0 {
 		t.Errorf("got: %v, want: %v", cid, DefaultChainConfigChainID)
 	}
+	// check is expected default 61
+	if cid.Cmp(DefaultChainConfigChainID) != 0 {
+		t.Errorf("got: %v, want: %v", cid, DefaultChainConfigChainID)
+	}
 
-	d = &ChainConfig{} // no chain id feature
+	// no chain id feature configured, should return zero-value (0)
+	d = &ChainConfig{}
 	cid = d.GetChainID()
+	// check is zero
 	if cid.Cmp(new(big.Int)) != 0 {
 		t.Errorf("got: %v, want: %v", cid, new(big.Int))
 	}

core/tx_pool.go

@@ -43,7 +43,6 @@ var (
 	ErrIntrinsicGas       = errors.New("Intrinsic gas too low")
 	ErrGasLimit           = errors.New("Exceeds block gas limit")
 	ErrNegativeValue      = errors.New("Negative value")
-	ErrChainID = errors.New("Invalid (zero-value) chain id")
 )
 
 const (
@@ -79,13 +78,9 @@ type TxPool struct {
 }
 
 func NewTxPool(config *ChainConfig, eventMux *event.TypeMux, currentStateFn stateFn, gasLimitFn func() *big.Int) *TxPool {
-	chainid := config.GetChainID()
-	if chainid.Cmp(new(big.Int)) == 0 {
-		panic(ErrChainID)
-	}
 	pool := &TxPool{
 		config:       config,
-		signer:       types.NewChainIdSigner(chainid),
+		signer:       types.NewChainIdSigner(config.GetChainID()),
 		pending:      make(map[common.Hash]*types.Transaction),
 		queue:        make(map[common.Address]map[common.Hash]*types.Transaction),
 		eventMux:     eventMux,

core/types/transaction_signing.go

@@ -137,10 +137,7 @@ func (s ChainIdSigner) Equal(s2 Signer) bool {
 	if !ok {
 		return false
 	}
-	if  other.chainId.Cmp(new(big.Int)) == 0 || other.chainId == nil {
-		return false
-	}
-	if s.chainId.Cmp(new(big.Int)) == 0 || s.chainId == nil {
+	if other.chainId == nil || s.chainId == nil {
 		return false
 	}
 

eth/api.go

@@ -825,11 +825,7 @@ func (s *PublicBlockChainAPI) rpcOutputBlock(b *types.Block, inclTx bool, fullTx
 		if fullTx {
 			formatTx = func(tx *types.Transaction) (interface{}, error) {
 				if tx.Protected() {
-					chainid := s.bc.Config().GetChainID()
-					if chainid.Cmp(new(big.Int)) == 0 {
-						return nil, errors.New("invalid chain configuration: chainid is zero-value")
-					}
-					tx.SetSigner(types.NewChainIdSigner(chainid))
+					tx.SetSigner(types.NewChainIdSigner(s.bc.Config().GetChainID()))
 				}
 				return newRPCTransaction(b, tx.Hash())
 			}

miner/worker.go

@@ -24,7 +24,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	"errors"
 	"github.com/ethereumproject/go-ethereum/accounts"
 	"github.com/ethereumproject/go-ethereum/common"
 	"github.com/ethereumproject/go-ethereum/core"
@@ -357,13 +356,9 @@ func (self *worker) makeCurrent(parent *types.Block, header *types.Header) error
 	if err != nil {
 		return err
 	}
-	chainid := self.config.GetChainID()
-	if chainid.Cmp(new(big.Int)) == 0 {
-		return errors.New("invalid chain configuration: chainid is zero-value")
-	}
 	work := &Work{
 		config:    self.config,
-		signer:    types.NewChainIdSigner(chainid),
+		signer:    types.NewChainIdSigner(self.config.GetChainID()),
 		state:     state,
 		ancestors: set.New(),
 		family:    set.New(),