wallet: drop publicKey from Account

It's not very useful and it's only available when we have a private key
anyway.

pkg/wallet/account.go

@@ -1,7 +1,6 @@
 package wallet
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 
@@ -21,9 +20,6 @@ type Account struct {
 	// NEO private key.
 	privateKey *keys.PrivateKey
 
-	// NEO public key.
-	publicKey []byte
-
 	// NEO public address.
 	Address string `json:"address"`
 
@@ -160,8 +156,6 @@ func (a *Account) Decrypt(passphrase string, scrypt keys.ScryptParams) error {
 		return err
 	}
 
-	a.publicKey = a.privateKey.PublicKey().Bytes()
-
 	return nil
 }
 
@@ -208,9 +202,13 @@ func (a *Account) ConvertMultisig(m int, pubs []*keys.PublicKey) error {
 	if a.Locked {
 		return errors.New("account is locked")
 	}
+	if a.privateKey == nil {
+		return errors.New("account key is not available (need to decrypt?)")
+	}
 	var found bool
+	accKey := a.privateKey.PublicKey()
 	for i := range pubs {
-		if bytes.Equal(a.publicKey, pubs[i].Bytes()) {
+		if accKey.Equal(pubs[i]) {
 			found = true
 			break
 		}
@@ -240,7 +238,6 @@ func NewAccountFromPrivateKey(p *keys.PrivateKey) *Account {
 	pubAddr := p.Address()
 
 	a := &Account{
-		publicKey:  pubKey.Bytes(),
 		privateKey: p,
 		Address:    pubAddr,
 		Contract: &Contract{

pkg/wallet/account_test.go

@@ -185,6 +185,13 @@ func TestAccount_ConvertMultisig(t *testing.T) {
 		require.Error(t, a.ConvertMultisig(1, pubs))
 		a.Locked = false
 	})
+	t.Run("no private key", func(t *testing.T) {
+		pk := a.privateKey
+		a.privateKey = nil
+		pubs := convertPubs(t, hexs)
+		require.Error(t, a.ConvertMultisig(0, pubs))
+		a.privateKey = pk
+	})
 	t.Run("invalid number of signatures", func(t *testing.T) {
 		pubs := convertPubs(t, hexs)
 		require.Error(t, a.ConvertMultisig(0, pubs))
@@ -223,7 +230,7 @@ func compareFields(t *testing.T, tk keytestcases.Ktype, acc *Account) {
 	require.Equalf(t, want, have, "expected address %s got %s", want, have)
 	want, have = tk.Wif, acc.privateKey.WIF()
 	require.Equalf(t, want, have, "expected wif %s got %s", want, have)
-	want, have = tk.PublicKey, hex.EncodeToString(acc.publicKey)
+	want, have = tk.PublicKey, hex.EncodeToString(acc.privateKey.PublicKey().Bytes())
 	require.Equalf(t, want, have, "expected pub key %s got %s", want, have)
 	want, have = tk.PrivateKey, acc.privateKey.String()
 	require.Equalf(t, want, have, "expected priv key %s got %s", want, have)

pkg/wallet/wallet_test.go

@@ -48,7 +48,6 @@ func TestAddAccount(t *testing.T) {
 
 	wallet.AddAccount(&Account{
 		privateKey:   nil,
-		publicKey:    nil,
 		Address:      "real",
 		EncryptedWIF: "",
 		Label:        "",
@@ -77,7 +76,6 @@ func TestSave(t *testing.T) {
 
 	wallet.AddAccount(&Account{
 		privateKey:   nil,
-		publicKey:    nil,
 		Address:      "",
 		EncryptedWIF: "",
 		Label:        "",