fix: fix index out of range undeterministic error in rpc test (#3718)

dot/state/block.go

@@ -51,11 +51,11 @@ var (
 // BlockState contains the historical block data of the blockchain, including block headers and bodies.
 // It wraps the blocktree (which contains unfinalised blocks) and the database (which contains finalised blocks).
 type BlockState struct {
-	bt        *blocktree.BlockTree
-	baseState *BaseState
-	dbPath    string
-	db        BlockStateDatabase
-	sync.RWMutex
+	bt                *blocktree.BlockTree
+	baseState         *BaseState
+	dbPath            string
+	db                BlockStateDatabase
+	lock              sync.RWMutex
 	genesisHash       common.Hash
 	lastFinalised     common.Hash
 	unfinalisedBlocks *hashToBlockMap
@@ -334,7 +334,7 @@ func (bs *BlockState) GetBlockHashesBySlot(slotNum uint64) ([]common.Hash, error
 		return nil, fmt.Errorf("failed to get descendants: %w", err)
 	}
 
-	blocksWithGivenSlot := []common.Hash{}
+	var blocksWithGivenSlot []common.Hash
 
 	for _, desc := range descendants {
 		descSlot, err := bs.GetSlotForBlock(desc)
@@ -380,8 +380,8 @@ func (bs *BlockState) GetBlockByNumber(num uint) (*types.Block, error) {
 
 // GetBlockByHash returns a block for a given hash
 func (bs *BlockState) GetBlockByHash(hash common.Hash) (*types.Block, error) {
-	bs.RLock()
-	defer bs.RUnlock()
+	bs.lock.RLock()
+	defer bs.lock.RUnlock()
 
 	block := bs.unfinalisedBlocks.getBlock(hash)
 	if block != nil {
@@ -413,8 +413,8 @@ func (bs *BlockState) SetHeader(header *types.Header) error {
 
 // HasBlockBody returns true if the db contains the block body
 func (bs *BlockState) HasBlockBody(hash common.Hash) (bool, error) {
-	bs.RLock()
-	defer bs.RUnlock()
+	bs.lock.RLock()
+	defer bs.lock.RUnlock()
 
 	if bs.unfinalisedBlocks.getBlock(hash) != nil {
 		return true, nil
@@ -471,8 +471,8 @@ func (bs *BlockState) CompareAndSetBlockData(bd *types.BlockData) error {
 
 // AddBlock adds a block to the blocktree and the DB with arrival time as current unix time
 func (bs *BlockState) AddBlock(block *types.Block) error {
-	bs.Lock()
-	defer bs.Unlock()
+	bs.lock.Lock()
+	defer bs.lock.Unlock()
 	return bs.AddBlockWithArrivalTime(block, time.Now())
 }
 
@@ -678,8 +678,7 @@ func (bs *BlockState) retrieveRange(startHash, endHash common.Hash) (hashes []co
 		return nil, fmt.Errorf("retrieving range from database: %w", err)
 	}
 
-	hashes = append(inDatabaseHashes, inMemoryHashes...)
-	return hashes, nil
+	return append(inDatabaseHashes, inMemoryHashes...), nil
 }
 
 var ErrStartHashMismatch = errors.New("start hash mismatch")
@@ -706,11 +705,8 @@ func (bs *BlockState) retrieveRangeFromDatabase(startHash common.Hash,
 
 	lastPosition := blocksInRange - 1
 
-	hashes[0] = startHash
-	hashes[lastPosition] = endHeader.Hash()
-
-	inLoopHash := endHeader.ParentHash
-	for currentPosition := lastPosition - 1; currentPosition > 0; currentPosition-- {
+	inLoopHash := endHeader.Hash()
+	for currentPosition := int(lastPosition); currentPosition >= 0; currentPosition-- {
 		hashes[currentPosition] = inLoopHash
 
 		inLoopHeader, err := bs.loadHeaderFromDatabase(inLoopHash)
@@ -721,9 +717,9 @@ func (bs *BlockState) retrieveRangeFromDatabase(startHash common.Hash,
 		inLoopHash = inLoopHeader.ParentHash
 	}
 
-	// here we ensure that we finished up the loop
+	// here we ensure that we finished up the loop with the hash we used as start
 	// with the same hash as the startHash
-	if inLoopHash != startHash {
+	if hashes[0] != startHash {
 		return nil, fmt.Errorf("%w: expecting %s, found: %s", ErrStartHashMismatch, startHash.Short(), inLoopHash.Short())
 	}
 

dot/state/block_finalisation.go

@@ -38,8 +38,8 @@ func (bs *BlockState) NumberIsFinalised(num uint) (bool, error) {
 
 // GetFinalisedHeader returns the finalised block header by round and setID
 func (bs *BlockState) GetFinalisedHeader(round, setID uint64) (*types.Header, error) {
-	bs.Lock()
-	defer bs.Unlock()
+	bs.lock.Lock()
+	defer bs.lock.Unlock()
 
 	h, err := bs.GetFinalisedHash(round, setID)
 	if err != nil {
@@ -116,8 +116,8 @@ func (bs *BlockState) GetHighestFinalisedHeader() (*types.Header, error) {
 
 // SetFinalisedHash sets the latest finalised block hash
 func (bs *BlockState) SetFinalisedHash(hash common.Hash, round, setID uint64) error {
-	bs.Lock()
-	defer bs.Unlock()
+	bs.lock.Lock()
+	defer bs.lock.Unlock()
 
 	has, err := bs.HasHeader(hash)
 	if err != nil {

dot/state/block_test.go

@@ -1099,3 +1099,35 @@ func Test_GetRuntime_StoreRuntime(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, runtimeInstance, sameRuntimeOnDiffHash)
 }
+
+const headerHex = "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" //nolint:lll
+//nolint:lll
+// This decodes to next Header -> ParentHash=0x276bfa91f70859348285599321ea96afd3ae681f0be47d36196bac8075ea32e8 Number=1 StateRoot=0x496b5fbd26d7014ba2ef84b588859428e334549d374726263ea894691ff78a0d ExtrinsicsRoot=0x34aea7c0b7cdadce2f44389a28d4200e522cec26d4eae828183ce40bd57ebeee Digest=[PreRuntimeDigest ConsensusEngineID=BABE Data=0x03000000002792f1100000000068ab0948ad2f3194f94c4a584bb8dc118d354316c10a51e04ce4ca7aed4a971c046b5dc4704d9fa43daad797291efa00a1070970f979d4593888dbcb7a628b08667ca7a2850eed67f908d9fce9ec45e6e688341d054d3f074ec102ae3844ca0f, ConsensusDigest ConsensusEngineID=BABE Data=0x0104d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d01000000000000000000000000000000000000000000000000000000000000000000000000000000, SealDigest ConsensusEngineID=BABE Data=0x6425bfe39b70f23a0de6b4e8159cf513c25cb7e18f52c6ba889f426211bb787dbe0f0a237cc93052f9fa8a68386722299b6c8ba0d8060ad6a1cbdb9688e9a982] Hash=0x885d464b8c8753f88973cfa457d385c8fe9c9d90a6a2f62e013cf81de3666812 //nolint:lll
+
+func Test_retrieveRangeFromDatabaseWithOneBlock(t *testing.T) {
+	ctrl := gomock.NewController(t)
+
+	telemetryMock := NewMockTelemetry(ctrl)
+	telemetryMock.EXPECT().SendMessage(gomock.Any()).AnyTimes()
+	db := NewInMemoryDB(t)
+	genesisHeader := &types.Header{
+		Number:    0,
+		StateRoot: trie.EmptyHash,
+		Digest:    types.NewDigest(),
+	}
+	bs, err := NewBlockStateFromGenesis(db, newTriesEmpty(), genesisHeader, telemetryMock)
+	require.NoError(t, err)
+
+	headerBytes, err := common.HexToBytes(headerHex)
+	require.NoError(t, err)
+
+	headerType := types.NewEmptyHeader()
+	err = scale.Unmarshal(headerBytes, headerType)
+	require.NoError(t, err)
+	err = bs.SetHeader(headerType)
+	require.NoError(t, err)
+
+	hashes, err := bs.retrieveRangeFromDatabase(headerType.Hash(), headerType)
+	require.NoError(t, err)
+	require.Equal(t, len(hashes), 1)
+}