fix markCanonicalChain bug

nimbus/db/db_chain.nim

@@ -332,13 +332,26 @@ proc headerExists*(self: BaseChainDB; blockHash: Hash256): bool =
   ## Returns True if the header with the given block hash is in our DB.
   self.db.contains(genericHashKey(blockHash).toOpenArray)
 
-proc markCanonicalChain(self: BaseChainDB, header: BlockHeader, headerHash: Hash256) =
+proc markCanonicalChain(self: BaseChainDB, header: BlockHeader, headerHash: Hash256): bool =
   ## mark this chain as canonical by adding block number to hash lookup
   ## down to forking point
   var
     currHash = headerHash
     currHeader = header
 
+  # mark current header as canonical
+  let key = blockNumberToHashKey(currHeader.blockNumber)
+  self.db.put(key.toOpenArray, rlp.encode(currHash))
+
+  # it is a genesis block, done
+  if currHeader.parentHash == Hash256():
+    return true
+
+  # mark ancestor blocks as canonical too
+  currHash = currHeader.parentHash
+  if not self.getBlockHeader(currHeader.parentHash, currHeader):
+    return false
+
   while currHash != Hash256():
     let key = blockNumberToHashKey(currHeader.blockNumber)
     let data = self.db.get(key.toOpenArray)
@@ -352,24 +365,34 @@ proc markCanonicalChain(self: BaseChainDB, header: BlockHeader, headerHash: Hash
       # forking point, done
       break
 
+    if currHeader.parentHash == Hash256():
+      break
+
     currHash = currHeader.parentHash
-    currHeader = self.getBlockHeader(currHeader.parentHash)
+    if not self.getBlockHeader(currHeader.parentHash, currHeader):
+      return false
+
+  return true
 
 proc setHead*(self: BaseChainDB, blockHash: Hash256): bool =
   var header: BlockHeader
   if not self.getBlockHeader(blockHash, header):
     return false
 
-  self.markCanonicalChain(header, blockHash)
+  if not self.markCanonicalChain(header, blockHash):
+    return false
+
   self.db.put(canonicalHeadHashKey().toOpenArray, rlp.encode(blockHash))
   return true
 
-proc setHead*(self: BaseChainDB, header: BlockHeader, writeHeader = false) =
+proc setHead*(self: BaseChainDB, header: BlockHeader, writeHeader = false): bool =
   var headerHash = rlpHash(header)
   if writeHeader:
     self.db.put(genericHashKey(headerHash).toOpenArray, rlp.encode(header))
-  self.markCanonicalChain(header, headerHash)
+  if not self.markCanonicalChain(header, headerHash):
+    return false
   self.db.put(canonicalHeadHashKey().toOpenArray, rlp.encode(headerHash))
+  return true
 
 proc persistReceipts*(self: BaseChainDB, receipts: openArray[Receipt]): Hash256 =
   var trie = initHexaryTrie(self.db)

nimbus/rpc/debug.nim

@@ -114,10 +114,10 @@ proc setupDebugRpc*(chainDB: BaseChainDB, rpcsrv: RpcServer) =
 
     result = traceBlock(chainDB, header, body, flags)
 
-  rpcsrv.rpc("debug_setHead") do(quantityTag: string):
+  rpcsrv.rpc("debug_setHead") do(quantityTag: string) -> bool:
     ## Sets the current head of the local chain by block number.
     ## Note, this is a destructive action and may severely damage your chain.
     ## Use with extreme caution.
     let
       header = chainDB.headerFromTag(quantityTag)
-    chainDB.setHead(header)
+    result = chainDB.setHead(header)

premix/dumper.nim

@@ -28,7 +28,7 @@ proc dumpDebug(chainDB: BaseChainDB, blockNumber: UInt256) =
     body = captureChainDB.getBlockBody(headerHash)
     vmState = BaseVMState.new(parent, header, captureChainDB)
 
-  captureChainDB.setHead(parent, true)
+  discard captureChainDB.setHead(parent, true)
   discard vmState.processBlockNotPoA(header, body)
 
   transaction.rollback()

premix/hunter.nim

@@ -95,7 +95,7 @@ proc huntProblematicBlock(blockNumber: UInt256): ValidationResult =
     # try to execute current block
     chainDB = newBaseChainDB(memoryDB, false)
 
-  chainDB.setHead(parentBlock.header, true)
+  discard chainDB.setHead(parentBlock.header, true)
 
   let transaction = memoryDB.beginTransaction()
   defer: transaction.dispose()

premix/persist.nim

@@ -47,7 +47,7 @@ proc main() {.used.} =
   # move head to block number ...
   if conf.head != 0.u256:
     var parentBlock = requestBlock(conf.head)
-    chainDB.setHead(parentBlock.header)
+    discard chainDB.setHead(parentBlock.header)
 
   if canonicalHeadHashKey().toOpenArray notin trieDB:
     persistToDb(db):

premix/prestate.nim

@@ -12,7 +12,7 @@ proc generatePrestate*(nimbus, geth: JsonNode, blockNumber: UInt256, parent, hea
     memoryDB = newMemoryDB()
     chainDB = newBaseChainDB(memoryDB, false)
 
-  chainDB.setHead(parent, true)
+  discard chainDB.setHead(parent, true)
   discard chainDB.persistTransactions(blockNumber, body.transactions)
   discard chainDB.persistUncles(body.uncles)
 

tests/persistBlockTestGen.nim

@@ -24,7 +24,7 @@ proc dumpTest(chainDB: BaseChainDB, blockNumber: int) =
     headers = @[header]
     bodies = @[blockBody]
 
-  captureChainDB.setHead(parent, true)
+  discard captureChainDB.setHead(parent, true)
   discard chain.persistBlocks(headers, bodies)
 
   var metaData = %{

tests/test_persistblock_json.nim

@@ -34,7 +34,8 @@ proc testFixture(node: JsonNode, testStatusIMPL: var TestStatus) =
     headers = @[header]
     bodies = @[blockBody]
 
-  chainDB.setHead(parent, true)
+  # it's ok if setHead fails here because of missing ancestors
+  discard chainDB.setHead(parent, true)
   let validationResult = chain.persistBlocks(headers, bodies)
   check validationResult == ValidationResult.OK