core: properly fixed processBlockHashHistory and added test

Author: MariusVanDerWijden

core/state_processor.go

@@ -296,13 +296,10 @@ func ProcessBlockHashHistory(statedb *state.StateDB, header *types.Header, chain
 	var low uint64
 	if number > params.HistoryServeWindow {
 		low = number - params.HistoryServeWindow
-		if number < params.HistoryServeWindow {
-			low = 0
-		}
 	}
-	for i := prevNumber - 1; i >= low; i-- {
-		ProcessParentBlockHash(statedb, i, parent.ParentHash)
-		parent = chain.GetHeader(parent.ParentHash, i)
+	for i := prevNumber; i > low; i-- {
+		ProcessParentBlockHash(statedb, i-1, parent.ParentHash)
+		parent = chain.GetHeader(parent.ParentHash, i-1)
 	}
 }
 

core/state_processor_test.go

@@ -18,6 +18,7 @@ package core
 
 import (
 	"crypto/ecdsa"
+	"encoding/binary"
 	"math/big"
 	"testing"
 
@@ -29,9 +30,11 @@ import (
 	"github.com/ethereum/go-ethereum/consensus/misc/eip1559"
 	"github.com/ethereum/go-ethereum/consensus/misc/eip4844"
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb/memorydb"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/trie"
 	"github.com/holiman/uint256"
@@ -528,3 +531,55 @@ func TestProcessVerkle(t *testing.T) {
 		}
 	}
 }
+
+type MockChain struct {
+	chain map[common.Hash]*types.Header
+}
+
+func (m *MockChain) Config() *params.ChainConfig { return nil }
+
+func (m *MockChain) CurrentHeader() *types.Header { return nil }
+
+func (m *MockChain) GetHeaderByNumber(number uint64) *types.Header { return nil }
+
+func (m *MockChain) GetTd(hash common.Hash, number uint64) *big.Int { return nil }
+
+func (m *MockChain) GetHeaderByHash(hash common.Hash) *types.Header {
+	return m.chain[hash]
+}
+
+func (m *MockChain) GetHeader(hash common.Hash, number uint64) *types.Header {
+	return m.chain[hash]
+}
+
+func TestProcessBlockHashHistory(t *testing.T) {
+	hashA := common.Hash{0x01}
+	hashB := common.Hash{0x02}
+	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabase(rawdb.NewDatabase(memorydb.New())), nil)
+	header := &types.Header{ParentHash: hashA, Number: big.NewInt(2)}
+	parent := &types.Header{ParentHash: hashB, Number: big.NewInt(1)}
+	parentParent := &types.Header{ParentHash: common.Hash{}, Number: big.NewInt(0)}
+	chainConfig := params.AllDevChainProtocolChanges
+	chainConfig.PragueTime = nil
+	chain := new(MockChain)
+	chain.chain = make(map[common.Hash]*types.Header)
+	chain.chain[hashA] = parent
+	chain.chain[hashB] = parentParent
+
+	ProcessBlockHashHistory(statedb, header, chainConfig, chain)
+
+	// make sure that the state is correct
+	if have := getParentBlockHash(statedb, 1); have != hashA {
+		t.Fail()
+	}
+	if have := getParentBlockHash(statedb, 0); have != hashB {
+		t.Fail()
+	}
+}
+
+func getParentBlockHash(statedb *state.StateDB, number uint64) common.Hash {
+	ringIndex := number % params.HistoryServeWindow
+	var key common.Hash
+	binary.BigEndian.PutUint64(key[24:], ringIndex)
+	return statedb.GetState(params.HistoryStorageAddress, key)
+}