fix(consensus): fix private chain initialization (#1987)

* revert: use masternodes from snapshot to verify vote

* fix underflow during chain initialization

* add previously removed test

* rename snapshot > snap for consistency

consensus/XDPoS/engines/engine_v2/timeout.go

@@ -129,7 +129,7 @@ func (x *XDPoS_v2) getTCEpochInfo(chain consensus.ChainReader, timeoutRound type
 		Number: epochSwitchInfo.EpochSwitchBlockInfo.Number,
 	}
 	log.Info("[getTCEpochInfo] Init epochInfo", "number", epochBlockInfo.Number, "round", epochRound, "tcRound", timeoutRound, "tcEpoch", tempTCEpoch)
-	for epochBlockInfo.Round > timeoutRound {
+	for epochBlockInfo.Round > timeoutRound && tempTCEpoch > 0 {
 		tempTCEpoch--
 		epochBlockInfo, err = x.GetBlockByEpochNumber(chain, tempTCEpoch)
 		if err != nil {

consensus/XDPoS/engines/engine_v2/vote.go

@@ -22,29 +22,22 @@ func (x *XDPoS_v2) VerifyVoteMessage(chain consensus.ChainReader, vote *types.Vo
 		return false, nil
 	}
 
-	// If we don't yet have the referenced header locally, defer verification.
+	snap, err := x.getSnapshot(chain, vote.GapNumber, true)
-	// Votes may arrive before the block header itself; avoid logging an error
-	// for that normal timing condition and let the vote be retried later.
-	if chain.GetHeaderByHash(vote.ProposedBlockInfo.Hash) == nil {
-		log.Debug("[VerifyVoteMessage] referenced header not present yet, defer verification", "blockNum", vote.ProposedBlockInfo.Number, "blockHash", vote.ProposedBlockInfo.Hash)
-		return false, nil
-	}
-
-	epochInfo, err := x.getEpochSwitchInfo(chain, nil, vote.ProposedBlockInfo.Hash)
 	if err != nil {
-		log.Error("[VerifyVoteMessage] Fail to get epochInfo when verifying vote message!", "blockNum", vote.ProposedBlockInfo.Number, "blockHash", vote.ProposedBlockInfo.Hash, "voteHash", vote.Hash(), "voteGapNumber", vote.GapNumber, "err", err)
+		log.Error("[VerifyVoteMessage] fail to get snapshot for a vote message", "blockNum", vote.ProposedBlockInfo.Number, "blockHash", vote.ProposedBlockInfo.Hash, "voteHash", vote.Hash(), "err", err)
 		return false, err
 	}
 
 	verified, signer, err := x.verifyMsgSignature(types.VoteSigHash(&types.VoteForSign{
 		ProposedBlockInfo: vote.ProposedBlockInfo,
 		GapNumber:         vote.GapNumber,
-	}), vote.Signature, epochInfo.Masternodes)
+	}), vote.Signature, snap.NextEpochCandidates)
+
 	if err != nil {
-		for i, mn := range epochInfo.Masternodes {
+		for i, mn := range snap.NextEpochCandidates {
 			log.Warn("[VerifyVoteMessage] Master node list item", "index", i, "Master node", mn.Hex())
 		}
-		log.Warn("[VerifyVoteMessage] Error while verifying vote message", "votedBlockNum", vote.ProposedBlockInfo.Number.Uint64(), "votedBlockHash", vote.ProposedBlockInfo.Hash.Hex(), "voteHash", vote.Hash(), "error", err.Error())
+		log.Warn("[VerifyVoteMessage] Error while verifying vote message", "votedBlockNum", vote.ProposedBlockInfo.Number.Uint64(), "votedBlockHash", vote.ProposedBlockInfo.Hash.Hex(), "voteHash", vote.Hash(), "err", err)
 		return false, err
 	}
 	vote.SetSigner(signer)
@@ -198,7 +191,7 @@ func (x *XDPoS_v2) verifyVotes(chain consensus.ChainReader, votes map[common.Has
 			})
 			verified, masterNode, err := x.verifyMsgSignature(signedVote, v.Signature, masternodes)
 			if err != nil {
-				log.Warn("[verifyVotes] error while verifying vote signature", "error", err.Error())
+				log.Warn("[verifyVotes] error while verifying vote signature", "err", err)
 				return
 			}
 

consensus/XDPoS/engines/engine_v2/vote_test.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/XinFinOrg/XDPoSChain/common"
 	"github.com/XinFinOrg/XDPoSChain/core/types"
-	"github.com/XinFinOrg/XDPoSChain/log"
 	"github.com/XinFinOrg/XDPoSChain/params"
 	"github.com/stretchr/testify/assert"
 )
@@ -96,63 +95,6 @@ func (m *MockChainReader) GetBlock(hash common.Hash, number uint64) *types.Block
 	return nil
 }
 
-// TestVerifyVoteMessage_HeaderNotPresent tests the behavior when a vote arrives
-// before its corresponding block header is available.
-//
-// This test verifies that VerifyVoteMessage handles the normal timing condition
-// where votes may arrive before the block header itself, returning (false, nil)
-// and logging at Debug level rather than Error level.
-func TestVerifyVoteMessage_HeaderNotPresent(t *testing.T) {
-	// Create a mock chain reader with no headers
-	mockChain := NewMockChainReader()
-
-	// Capture logs to ensure Debug (and no Error) is emitted
-	memHandler := newMemoryHandler()
-	log.SetDefault(log.NewLogger(memHandler))
-	defer log.SetDefault(log.NewLogger(log.DiscardHandler()))
-
-	// Create the XDPoS_v2 engine
-	engine := &XDPoS_v2{
-		currentRound: 10,
-		lock:         sync.RWMutex{},
-	}
-
-	// Create a vote for a block that doesn't exist in the chain
-	vote := &types.Vote{
-		ProposedBlockInfo: &types.BlockInfo{
-			Hash:   common.StringToHash("nonexistent-block"),
-			Round:  10,
-			Number: big.NewInt(100),
-		},
-		Signature: make([]byte, 65),
-		GapNumber: 0,
-	}
-
-	// Call VerifyVoteMessage
-	verified, err := engine.VerifyVoteMessage(mockChain, vote)
-
-	// Verify the expected behavior:
-	// 1. Should return false (not verified)
-	assert.False(t, verified, "Should return false when header is not present")
-
-	// 2. Should return nil error (deferred verification)
-	assert.NoError(t, err, "Should not error when header is absent; vote will be retried")
-
-	// 3. Should log at Debug level and not emit Error-level logs
-	records := memHandler.Records()
-	var hasDebug, hasError bool
-	for _, rec := range records {
-		switch rec.Level {
-		case slog.LevelDebug:
-			hasDebug = true
-		case slog.LevelError, log.LevelCrit:
-			hasError = true
-		}
-	}
-	assert.True(t, hasDebug, "Expected a debug log when header is missing")
-	assert.False(t, hasError, "Should not emit error-level logs for missing header")
-}
-
 // TestVerifyVoteMessage_VoteRoundTooOld tests that votes with rounds below
 // the current round are rejected immediately
 func TestVerifyVoteMessage_VoteRoundTooOld(t *testing.T) {

consensus/tests/engine_v2_tests/vote_test.go

@@ -536,6 +536,32 @@ func TestVerifyVoteMsg(t *testing.T) {
 	assert.Nil(t, err)
 }
 
+func TestVoteMsgMissingSnapshot(t *testing.T) {
+	blockchain, _, currentBlock, signer, signFn, _ := PrepareXDCTestBlockChainForV2Engine(t, 915, params.TestXDPoSMockChainConfig, nil)
+	engineV2 := blockchain.Engine().(*XDPoS.XDPoS).EngineV2
+
+	blockInfo := &types.BlockInfo{
+		Hash:   currentBlock.Hash(),
+		Round:  types.Round(14),
+		Number: big.NewInt(915),
+	}
+	voteForSign := &types.VoteForSign{
+		ProposedBlockInfo: blockInfo,
+		GapNumber:         450,
+	}
+
+	signHash, _ := signFn(accounts.Account{Address: signer}, types.VoteSigHash(voteForSign).Bytes())
+	voteMsg := &types.Vote{
+		ProposedBlockInfo: blockInfo,
+		Signature:         signHash,
+		GapNumber:         1350, // missing 1350 snapshot
+	}
+	engineV2.SetNewRoundFaker(blockchain, types.Round(14), false)
+	verified, err := engineV2.VerifyVoteMessage(blockchain, voteMsg)
+	assert.False(t, verified)
+	assert.NotNil(t, err)
+}
+
 func TestVoteMessageHandlerWrongGapNumber(t *testing.T) {
 	blockchain, _, currentBlock, signer, signFn, _ := PrepareXDCTestBlockChainForV2Engine(t, 905, params.TestXDPoSMockChainConfig, nil)
 	engineV2 := blockchain.Engine().(*XDPoS.XDPoS).EngineV2