core: check of ancientdb, backport bnb-chain/bsc#817

Signed-off-by: Delweng <delweng@gmail.com>

core/headerchain.go

@@ -168,6 +168,9 @@ func (hc *HeaderChain) Reorg(headers []*types.Header) error {
 			headHash   = header.Hash()
 		)
 		for rawdb.ReadCanonicalHash(hc.chainDb, headNumber) != headHash {
+			if frozen, _ := hc.chainDb.Ancients(); frozen == headNumber {
+				break
+			}
 			rawdb.WriteCanonicalHash(batch, headHash, headNumber)
 			if headNumber == 0 {
 				break // It shouldn't be reached

core/rawdb/chain_iterator.go

@@ -99,7 +99,10 @@ func iterateTransactions(db ethdb.Database, from uint64, to uint64, reverse bool
 		number uint64
 		rlp    rlp.RawValue
 	}
-	if to == from {
+	if offset := db.AncientOffSet(); offset > from {
+		from = offset
+	}
+	if to <= from {
 		return nil
 	}
 	threads := to - from

eth/state_accessor.go

@@ -72,6 +72,9 @@ func (eth *Ethereum) StateAtBlock(block *types.Block, reexec uint64, base *state
 		// The optional base statedb is given, mark the start point as parent block
 		statedb, database, report = base, base.Database(), false
 		current = eth.blockchain.GetBlock(block.ParentHash(), block.NumberU64()-1)
+		if current == nil {
+			return nil, fmt.Errorf("missing parent block %v %d", block.ParentHash(), block.NumberU64()-1)
+		}
 	} else {
 		// Otherwise try to reexec blocks until we find a state or reach our limit
 		current = block

internal/ethapi/api.go

@@ -636,6 +636,9 @@ func (s *PublicBlockChainAPI) GetTransactionReceiptsByBlock(ctx context.Context,
 	if err != nil {
 		return nil, err
 	}
+	if receipts == nil {
+		return nil, fmt.Errorf("block %d receipts not found", block.NumberU64())
+	}
 
 	txs := block.Transactions()