Merge pull request #2028 from nspcc-dev/core/fix-add-headers

core: allow to add several headers with StateRootInHeader on

pkg/core/blockchain.go

@@ -782,6 +782,15 @@ func (bc *Blockchain) storeBlock(block *block.Block, txpool *mempool.Pool) error
 		// because changes applied are the ones from HALTed transactions.
 		return fmt.Errorf("error while trying to apply MPT changes: %w", err)
 	}
+	if bc.config.StateRootInHeader && bc.HeaderHeight() > sr.Index {
+		h, err := bc.GetHeader(bc.GetHeaderHash(int(sr.Index) + 1))
+		if err != nil {
+			return fmt.Errorf("failed to get next header: %w", err)
+		}
+		if h.PrevStateRoot != sr.Root {
+			return fmt.Errorf("local stateroot and next header's PrevStateRoot mismatch: %s vs %s", sr.Root.StringBE(), h.PrevStateRoot.StringBE())
+		}
+	}
 
 	if bc.config.SaveStorageBatch {
 		bc.lastBatch = cache.DAO.GetBatch()
@@ -1430,9 +1439,11 @@ var (
 
 func (bc *Blockchain) verifyHeader(currHeader, prevHeader *block.Header) error {
 	if bc.config.StateRootInHeader {
-		if sr := bc.stateRoot.CurrentLocalStateRoot(); currHeader.PrevStateRoot != sr {
-			return fmt.Errorf("%w: %s != %s",
-				ErrHdrInvalidStateRoot, currHeader.PrevStateRoot.StringLE(), sr.StringLE())
+		if bc.stateRoot.CurrentLocalHeight() == prevHeader.Index {
+			if sr := bc.stateRoot.CurrentLocalStateRoot(); currHeader.PrevStateRoot != sr {
+				return fmt.Errorf("%w: %s != %s",
+					ErrHdrInvalidStateRoot, currHeader.PrevStateRoot.StringLE(), sr.StringLE())
+			}
 		}
 	}
 	if prevHeader.Hash() != currHeader.PrevHash {

pkg/core/blockchain_test.go

@@ -158,6 +158,28 @@ func TestAddBlockStateRoot(t *testing.T) {
 	require.NoError(t, bc.AddBlock(b))
 }
 
+func TestAddHeadersStateRoot(t *testing.T) {
+	bc := newTestChainWithCustomCfg(t, func(c *config.Config) {
+		c.ProtocolConfiguration.StateRootInHeader = true
+	})
+
+	r := bc.stateRoot.CurrentLocalStateRoot()
+	h1 := bc.newBlock().Header
+
+	// invalid stateroot
+	h1.PrevStateRoot[0] ^= 0xFF
+	require.True(t, errors.Is(bc.AddHeaders(&h1), ErrHdrInvalidStateRoot))
+
+	// valid stateroot
+	h1.PrevStateRoot = r
+	require.NoError(t, bc.AddHeaders(&h1))
+
+	// unable to verify stateroot (stateroot is computed for block #0 only => can
+	// verify stateroot of header #1 only) => just store the header
+	h2 := newBlockWithState(bc.config, 2, h1.Hash(), nil).Header
+	require.NoError(t, bc.AddHeaders(&h2))
+}
+
 func TestAddBadBlock(t *testing.T) {
 	bc := newTestChain(t)
 	// It has ValidUntilBlock == 0, which is wrong

pkg/core/stateroot/module.go

@@ -70,6 +70,11 @@ func (s *Module) CurrentLocalStateRoot() util.Uint256 {
 	return s.currentLocal.Load().(util.Uint256)
 }
 
+// CurrentLocalHeight returns height of the local state root.
+func (s *Module) CurrentLocalHeight() uint32 {
+	return s.localHeight.Load()
+}
+
 // CurrentValidatedHeight returns current state root validated height.
 func (s *Module) CurrentValidatedHeight() uint32 {
 	return s.validatedHeight.Load()