acounts/keystore, cmd/faucet: fix faucet double import (ethereum#21172)

accounts/keystore/keystore.go

@@ -43,6 +43,10 @@ var (
 	ErrLocked  = accounts.NewAuthNeededError("password or unlock")
 	ErrNoMatch = errors.New("no key for given address or file")
 	ErrDecrypt = errors.New("could not decrypt key with given password")
+
+	// ErrAccountAlreadyExists is returned if an account attempted to import is
+	// already present in the keystore.
+	ErrAccountAlreadyExists = errors.New("account alreaady exists")
 )
 
 // KeyStoreType is the reflect type of a keystore backend.
@@ -453,7 +457,7 @@ func (ks *KeyStore) Import(keyJSON []byte, passphrase, newPassphrase string) (ac
 	ks.importMu.Lock()
 	defer ks.importMu.Unlock()
 	if ks.cache.hasAddress(key.Address) {
-		return accounts.Account{}, errors.New("account already exists")
+		return accounts.Account{}, ErrAccountAlreadyExists
 	}
 	return ks.importKey(key, newPassphrase)
 }
@@ -464,7 +468,7 @@ func (ks *KeyStore) ImportECDSA(priv *ecdsa.PrivateKey, passphrase string) (acco
 	ks.importMu.Lock()
 	defer ks.importMu.Unlock()
 	if ks.cache.hasAddress(key.Address) {
-		return accounts.Account{}, errors.New("account already exists")
+		return accounts.Account{}, ErrAccountAlreadyExists
 	}
 	return ks.importKey(key, passphrase)
 }

cmd/faucet/faucet.go

@@ -163,7 +163,7 @@ func main() {
 		log.Crit("Failed to read account key contents", "file", *accJSONFlag, "err", err)
 	}
 	acc, err := ks.Import(blob, pass, pass)
-	if err != nil {
+	if err != nil && err != keystore.ErrAccountAlreadyExists {
 		log.Crit("Failed to import faucet signer account", "err", err)
 	}
 	ks.Unlock(acc, pass)
@@ -710,8 +710,11 @@ func authTwitter(url string) (string, string, common.Address, error) {
 		return "", "", common.Address{}, errors.New("invalid Twitter status URL")
 	}
 	// Twitter's API isn't really friendly with direct links. Still, we don't
-	// want to do ask read permissions from users, so just load the public posts and
-	// scrape it for the Ethereum address and profile URL.
+	// want to do ask read permissions from users, so just load the public posts
+	// and scrape it for the Ethereum address and profile URL. We need to load
+	// the mobile page though since the main page loads tweet contents via JS.
+	url = strings.Replace(url, "https://twitter.com/", "https://mobile.twitter.com/", 1)
+
 	res, err := http.Get(url)
 	if err != nil {
 		return "", "", common.Address{}, err