add haveBlockAndState to BaseChainDB and use it in engine api

nimbus/db/db_chain.nim

@@ -478,3 +478,10 @@ proc safeHeader*(self: BaseChainDB): BlockHeader =
 
 proc finalizedHeader*(self: BaseChainDB): BlockHeader =
   self.getBlockHeader(self.finalizedHeaderHash)
+
+proc haveBlockAndState*(self: BaseChainDB, headerHash: Hash256): bool =
+  var header: BlockHeader
+  if not self.getBlockHeader(headerHash, header):
+    return false
+  # see if stateRoot exists
+  self.exists(header.stateRoot)

nimbus/merge/mergeutils.nim

@@ -105,6 +105,12 @@ proc invalidStatus*(validHash: Hash256 = Hash256()): PayloadStatusV1 =
     latestValidHash: some(BlockHash validHash.data)
   )
 
+proc acceptedStatus*(validHash: Hash256): PayloadStatusV1 =
+  PayloadStatusV1(
+    status: PayloadExecutionStatus.accepted,
+    latestValidHash: some(BlockHash validHash.data)
+  )
+
 proc toBlockBody*(payload: ExecutionPayloadV1): BlockBody =
   result.transactions.setLen(payload.transactions.len)
   for i, tx in payload.transactions:

nimbus/rpc/engine_api.nim

@@ -20,6 +20,15 @@ import
 
 import eth/common/eth_types except BlockHeader
 
+proc latestValidHash(db: BaseChainDB, parent: EthBlockHeader, ttd: DifficultyInt): Hash256 =
+  let ptd = db.getScore(parent.parentHash)
+  if ptd >= ttd:
+    db.getHeadBlockHash()
+  else:
+    # If the most recent valid ancestor is a PoW block,
+    # latestValidHash MUST be set to ZERO
+    Hash256()
+
 proc setupEngineAPI*(
     sealingEngine: SealingEngineRef,
     server: RpcServer) =
@@ -91,18 +100,20 @@ proc setupEngineAPI*(
         parent = header.timestamp, header = header.timestamp
       return invalidStatus(db.getHeadBlockHash(), "Invalid timestamp")
 
+    if not db.haveBlockAndState(header.parentHash):
+      api.put(blockHash, header)
+      warn "State not available, ignoring new payload",
+        hash = blockHash.data.toHex,
+        number = header.blockNumber
+      let blockHash = latestValidHash(db, parent, ttd)
+      return acceptedStatus(blockHash)
+
     trace "Inserting block without sethead",
       hash = blockHash.data.toHex, number = header.blockNumber
     let body = toBlockBody(payload)
     let vres = sealingEngine.chain.insertBlockWithoutSetHead(header, body)
     if vres != ValidationResult.OK:
-      let ptd = db.getScore(parent.parentHash)
-      let blockHash = if ptd >= ttd:
-                        db.getHeadBlockHash()
-                      else:
-                        # If the most recent valid ancestor is a PoW block,
-                        # latestValidHash MUST be set to ZERO
-                        Hash256()
+      let blockHash = latestValidHash(db, parent, ttd)
       return invalidStatus(blockHash, "Failed to insert block")
 
     # We've accepted a valid payload from the beacon client. Mark the local