core/rawdb: skip missing block bodies during tx unindexing (#33573)

This PR fixes an issue where the tx indexer would repeatedly try to
“unindex” a block with a missing body, causing a spike in CPU usage.
This change skips these blocks and advances the index tail. The fix was
verified both manually on a local development chain and with a new test.

resolves #33371

core/rawdb/chain_iterator.go

@@ -87,6 +87,7 @@ func InitDatabaseFromFreezer(db ethdb.Database) {
 type blockTxHashes struct {
 	number uint64
 	hashes []common.Hash
+	err    error
 }
 
 // iterateTransactions iterates over all transactions in the (canon) block
@@ -144,17 +145,22 @@ func iterateTransactions(db ethdb.Database, from uint64, to uint64, reverse bool
 		}()
 		for data := range rlpCh {
 			var body types.Body
+			var result *blockTxHashes
 			if err := rlp.DecodeBytes(data.rlp, &body); err != nil {
 				log.Warn("Failed to decode block body", "block", data.number, "error", err)
-				return
-			}
-			var hashes []common.Hash
-			for _, tx := range body.Transactions {
-				hashes = append(hashes, tx.Hash())
-			}
-			result := &blockTxHashes{
-				hashes: hashes,
-				number: data.number,
+				result = &blockTxHashes{
+					number: data.number,
+					err:    err,
+				}
+			} else {
+				var hashes []common.Hash
+				for _, tx := range body.Transactions {
+					hashes = append(hashes, tx.Hash())
+				}
+				result = &blockTxHashes{
+					hashes: hashes,
+					number: data.number,
+				}
 			}
 			// Feed the block to the aggregator, or abort on interrupt
 			select {
@@ -214,6 +220,10 @@ func indexTransactions(db ethdb.Database, from uint64, to uint64, interrupt chan
 			// Next block available, pop it off and index it
 			delivery := queue.PopItem()
 			lastNum = delivery.number
+			if delivery.err != nil {
+				log.Warn("Skipping tx indexing for block with missing/corrupt body", "block", delivery.number, "error", delivery.err)
+				continue
+			}
 			WriteTxLookupEntries(batch, delivery.number, delivery.hashes)
 			blocks++
 			txs += len(delivery.hashes)
@@ -307,6 +317,10 @@ func unindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt ch
 			}
 			delivery := queue.PopItem()
 			nextNum = delivery.number + 1
+			if delivery.err != nil {
+				log.Warn("Skipping tx unindexing for block with missing/corrupt body", "block", delivery.number, "error", delivery.err)
+				continue
+			}
 			DeleteTxLookupEntries(batch, delivery.hashes)
 			txs += len(delivery.hashes)
 			blocks++

core/rawdb/chain_iterator_test.go

@@ -218,6 +218,36 @@ func TestIndexTransactions(t *testing.T) {
 	verify(0, 8, false, 8)
 }
 
+func TestUnindexTransactionsMissingBody(t *testing.T) {
+	// Construct test chain db
+	chainDB := NewMemoryDatabase()
+	blocks, _ := initDatabaseWithTransactions(chainDB)
+
+	// Index the entire chain.
+	lastBlock := blocks[len(blocks)-1].NumberU64()
+	IndexTransactions(chainDB, 0, lastBlock+1, nil, false)
+
+	// Prove that block 2 body exists in the database.
+	if raw := ReadCanonicalBodyRLP(chainDB, 2, nil); len(raw) == 0 {
+		t.Fatalf("Block 2 body does not exist in the database.")
+	}
+
+	// Delete body for block 2. This simulates a corrupted database.
+	key := blockBodyKey(2, blocks[2].Hash())
+	if err := chainDB.Delete(key); err != nil {
+		t.Fatalf("Failed to delete block body %v", err)
+	}
+
+	// Unindex blocks [0, 3)
+	UnindexTransactions(chainDB, 0, 3, nil, false)
+
+	// Verify that tx index tail is updated to 3.
+	tail := ReadTxIndexTail(chainDB)
+	if tail == nil || *tail != 3 {
+		t.Fatalf("The tx index tail is wrong: got %v want %d", *tail, 3)
+	}
+}
+
 func TestPruneTransactionIndex(t *testing.T) {
 	chainDB := NewMemoryDatabase()
 	blocks, _ := initDatabaseWithTransactions(chainDB)