core: transaction nonce recovery fix

When the transaction state recovery kicked in it assigned the last
(incorrect) nonce to the pending state which caused transactions with
the same nonce to occur.

Added test for nonce recovery

2 files changed, 21 insertions, 2 deletions

diff --git a/core/transaction_pool.go b/core/transaction_pool.go
index 42e26b3b3..513600be3 100644
--- a/core/transaction_pool.go
+++ b/core/transaction_pool.go
@@ -121,8 +121,8 @@ func (pool *TxPool) resetState() {
 		if addr, err := tx.From(); err == nil {
 			// Set the nonce. Transaction nonce can never be lower
 			// than the state nonce; validatePool took care of that.
-			if pool.pendingState.GetNonce(addr) < tx.Nonce() {
-				pool.pendingState.SetNonce(addr, tx.Nonce())
+			if pool.pendingState.GetNonce(addr) <= tx.Nonce() {
+				pool.pendingState.SetNonce(addr, tx.Nonce()+1)
 			}
 		}
 	}
diff --git a/core/transaction_pool_test.go b/core/transaction_pool_test.go
index 7d0984740..d9267cc43 100644
--- a/core/transaction_pool_test.go
+++ b/core/transaction_pool_test.go
@@ -219,3 +219,22 @@ func TestMissingNonce(t *testing.T) {
 		t.Error("expected 1 queued transaction, got", len(pool.queue[addr]))
 	}
 }
+
+func TestNonceRecovery(t *testing.T) {
+	const n = 10
+	pool, key := setupTxPool()
+	addr := crypto.PubkeyToAddress(key.PublicKey)
+	pool.currentState().SetNonce(addr, n)
+	pool.currentState().AddBalance(addr, big.NewInt(100000000000000))
+	pool.resetState()
+	tx := transaction(n, big.NewInt(100000), key)
+	if err := pool.Add(tx); err != nil {
+		t.Error(err)
+	}
+	// simulate some weird re-order of transactions and missing nonce(s)
+	pool.currentState().SetNonce(addr, n-1)
+	pool.resetState()
+	if fn := pool.pendingState.GetNonce(addr); fn != n+1 {
+		t.Errorf("expected nonce to be %d, got %d", n+1, fn)
+	}
+}