From 2590a7dabbf6781734be0c388b46ecd53ece6155 Mon Sep 17 00:00:00 2001
From: obscuren <geffobscura@gmail.com>
Date: Thu, 30 Apr 2015 00:08:43 +0200
Subject: [PATCH] core: added some additional chain tests for shortest chain

---
 core/chain_manager.go      |  2 +-
 core/chain_manager_test.go | 33 +++++++++++++++++++++++++++++----
 2 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/core/chain_manager.go b/core/chain_manager.go
index 253228bfd8..4fdb2edceb 100644
--- a/core/chain_manager.go
+++ b/core/chain_manager.go
@@ -593,7 +593,7 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
 				}
 			} else {
 				if glog.V(logger.Detail) {
-					glog.Infof("inserted forked block #%d (%d TXs %d UNCs) (%x...)\n", block.Number(), len(block.Transactions()), len(block.Uncles()), block.Hash().Bytes()[0:4])
+					glog.Infof("inserted forked block #%d (TD=%v) (%d TXs %d UNCs) (%x...)\n", block.Number(), block.Difficulty(), len(block.Transactions()), len(block.Uncles()), block.Hash().Bytes()[0:4])
 				}
 
 				queue[i] = ChainSideEvent{block, logs}
diff --git a/core/chain_manager_test.go b/core/chain_manager_test.go
index 8d1b7865df..50915459b9 100644
--- a/core/chain_manager_test.go
+++ b/core/chain_manager_test.go
@@ -9,6 +9,7 @@ import (
 	"strconv"
 	"testing"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethdb"
@@ -369,11 +370,8 @@ func makeChainWithDiff(genesis *types.Block, d []int, seed byte) []*types.Block
 	return chain
 }
 
-func TestReorg(t *testing.T) {
-	db, _ := ethdb.NewMemDatabase()
+func chm(genesis *types.Block, db common.Database) *ChainManager {
 	var eventMux event.TypeMux
-
-	genesis := GenesisBlock(db)
 	bc := &ChainManager{blockDb: db, stateDb: db, genesisBlock: genesis, eventMux: &eventMux}
 	bc.cache = NewBlockCache(100)
 	bc.futureBlocks = NewBlockCache(100)
@@ -381,6 +379,14 @@ func TestReorg(t *testing.T) {
 	bc.ResetWithGenesisBlock(genesis)
 	bc.txState = state.ManageState(bc.State())
 
+	return bc
+}
+
+func TestReorgLongest(t *testing.T) {
+	db, _ := ethdb.NewMemDatabase()
+	genesis := GenesisBlock(db)
+	bc := chm(genesis, db)
+
 	chain1 := makeChainWithDiff(genesis, []int{1, 2, 4}, 10)
 	chain2 := makeChainWithDiff(genesis, []int{1, 2, 3, 4}, 11)
 
@@ -394,3 +400,22 @@ func TestReorg(t *testing.T) {
 		}
 	}
 }
+
+func TestReorgShortest(t *testing.T) {
+	db, _ := ethdb.NewMemDatabase()
+	genesis := GenesisBlock(db)
+	bc := chm(genesis, db)
+
+	chain1 := makeChainWithDiff(genesis, []int{1, 2, 3, 4}, 10)
+	chain2 := makeChainWithDiff(genesis, []int{1, 10}, 11)
+
+	bc.InsertChain(chain1)
+	bc.InsertChain(chain2)
+
+	prev := bc.CurrentBlock()
+	for block := bc.GetBlockByNumber(bc.CurrentBlock().NumberU64() - 1); block.NumberU64() != 0; prev, block = block, bc.GetBlockByNumber(block.NumberU64()-1) {
+		if prev.ParentHash() != block.Hash() {
+			t.Errorf("parent hash mismatch %x - %x", prev.ParentHash(), block.Hash())
+		}
+	}
+}