From 0b493910d38c4f6ed25a196b0e8071dc2afd1fd6 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Mon, 8 Jun 2015 02:19:39 +0200
Subject: [PATCH] core: fix the nonce check one more time

The block nonce verification was effectively disabled by a typo.
This time, there is an actual test for it.
---
 core/chain_manager.go      |  6 ++---
 core/chain_manager_test.go | 53 ++++++++++++++++++++++++++++++++++++++
 core/error.go              | 17 ++++++++++++
 3 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/core/chain_manager.go b/core/chain_manager.go
index 86d1c1454..291e411ae 100644
--- a/core/chain_manager.go
+++ b/core/chain_manager.go
@@ -551,12 +551,12 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
 		bstart := time.Now()
 		// Wait for block i's nonce to be verified before processing
 		// its state transition.
-		for nonceChecked[i] {
+		for !nonceChecked[i] {
 			r := <-nonceDone
 			nonceChecked[r.i] = true
 			if !r.valid {
-				block := chain[i]
-				return i, ValidationError("Block (#%v / %x) nonce is invalid (= %x)", block.Number(), block.Hash(), block.Nonce)
+				block := chain[r.i]
+				return r.i, &BlockNonceErr{Hash: block.Hash(), Number: block.Number(), Nonce: block.Nonce()}
 			}
 		}
 
diff --git a/core/chain_manager_test.go b/core/chain_manager_test.go
index 560e85f77..45bec7140 100644
--- a/core/chain_manager_test.go
+++ b/core/chain_manager_test.go
@@ -3,6 +3,7 @@ package core
 import (
 	"fmt"
 	"math/big"
+	"math/rand"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -426,3 +427,55 @@ func TestReorgShortest(t *testing.T) {
 		}
 	}
 }
+
+func TestInsertNonceError(t *testing.T) {
+	for i := 1; i < 25 && !t.Failed(); i++ {
+		db, _ := ethdb.NewMemDatabase()
+		genesis := GenesisBlock(db)
+		bc := chm(genesis, db)
+		bc.processor = NewBlockProcessor(db, db, bc.pow, bc, bc.eventMux)
+		blocks := makeChain(bc.processor.(*BlockProcessor), bc.currentBlock, i, db, 0)
+
+		fail := rand.Int() % len(blocks)
+		failblock := blocks[fail]
+		bc.pow = failpow{failblock.NumberU64()}
+		n, err := bc.InsertChain(blocks)
+
+		// Check that the returned error indicates the nonce failure.
+		if n != fail {
+			t.Errorf("(i=%d) wrong failed block index: got %d, want %d", i, n, fail)
+		}
+		if !IsBlockNonceErr(err) {
+			t.Fatalf("(i=%d) got %q, want a nonce error", i, err)
+		}
+		nerr := err.(*BlockNonceErr)
+		if nerr.Number.Cmp(failblock.Number()) != 0 {
+			t.Errorf("(i=%d) wrong block number in error, got %v, want %v", i, nerr.Number, failblock.Number())
+		}
+		if nerr.Hash != failblock.Hash() {
+			t.Errorf("(i=%d) wrong block hash in error, got %v, want %v", i, nerr.Hash, failblock.Hash())
+		}
+
+		// Check that all no blocks after the failing block have been inserted.
+		for _, block := range blocks[fail:] {
+			if bc.HasBlock(block.Hash()) {
+				t.Errorf("(i=%d) invalid block %d present in chain", i, block.NumberU64())
+			}
+		}
+	}
+}
+
+// failpow returns false from Verify for a certain block number.
+type failpow struct{ num uint64 }
+
+func (pow failpow) Search(pow.Block, <-chan struct{}) (nonce uint64, mixHash []byte) {
+	return 0, nil
+}
+func (pow failpow) Verify(b pow.Block) bool {
+	return b.NumberU64() != pow.num
+}
+func (pow failpow) GetHashrate() int64 {
+	return 0
+}
+func (pow failpow) Turbo(bool) {
+}
diff --git a/core/error.go b/core/error.go
index 2bdad364f..3f3c350df 100644
--- a/core/error.go
+++ b/core/error.go
@@ -90,6 +90,23 @@ func IsNonceErr(err error) bool {
 	return ok
 }
 
+// BlockNonceErr indicates that a block's nonce is invalid.
+type BlockNonceErr struct {
+	Number *big.Int
+	Hash   common.Hash
+	Nonce  uint64
+}
+
+func (err *BlockNonceErr) Error() string {
+	return fmt.Sprintf("block %d (%v) nonce is invalid (got %d)", err.Number, err.Hash, err.Nonce)
+}
+
+// IsBlockNonceErr returns true for invalid block nonce errors.
+func IsBlockNonceErr(err error) bool {
+	_, ok := err.(*BlockNonceErr)
+	return ok
+}
+
 type InvalidTxErr struct {
 	Message string
 }