Adjust for optional totalDifficulty in JSON-RPC BlockObject

execution_chain/rpc/rpc_utils.nim

@@ -128,7 +128,7 @@ proc populateTransactionObject*(tx: Transaction,
 
 proc populateBlockObject*(blockHash: Hash32,
                           blk: Block,
-                          totalDifficulty: UInt256,
+                          totalDifficulty: Opt[UInt256],
                           fullTx: bool,
                           withUncles: bool = false): BlockObject =
   template header: auto = blk.header
@@ -389,3 +389,7 @@ proc getEthConfigObject*(com: CommonRef,
     res.last = Opt.none(ConfigObject)
 
   return res
+
+proc getTotalDifficulty*(chain: ForkedChainRef, blockHash: Hash32): Opt[UInt256] =
+  # Note: It's ok to use baseTxFrame for TD as this is for historical blocks
+  chain.baseTxFrame().getScore(blockHash)

execution_chain/rpc/server_api.nim

@@ -48,11 +48,8 @@ template chain(api: ServerAPIRef): ForkedChainRef =
 func newServerAPI*(txPool: TxPoolRef): ServerAPIRef =
   ServerAPIRef(txPool: txPool)
 
-proc getTotalDifficulty*(api: ServerAPIRef, blockHash: Hash32): UInt256 =
-  # TODO forkedchain!
-  let totalDifficulty = api.com.db.baseTxFrame().getScore(blockHash).valueOr:
-    return api.com.db.baseTxFrame().headTotalDifficulty()
-  return totalDifficulty
+proc getTotalDifficulty*(api: ServerAPIRef, blockHash: Hash32): Opt[UInt256] =
+  api.txPool.chain.getTotalDifficulty(blockHash)
 
 proc getProof*(
     accDB: LedgerRef, address: Address, slots: seq[UInt256]

portal/bridge/common/rpc_helpers.nim

@@ -145,7 +145,7 @@ proc getHeaderByNumber*(
 
 proc getBlockByNumber*(
     client: RpcClient, blockId: BlockIdentifier
-): Future[Result[(Header, BlockBody, UInt256), string]] {.
+): Future[Result[(Header, BlockBody, Opt[UInt256]), string]] {.
     async: (raises: [CancelledError])
 .} =
   let blockObject =

portal/tools/eth_data_exporter.nim

@@ -109,7 +109,7 @@ proc cmdExportEra1(config: ExporterConf) =
       var headerRecords: seq[historical_hashes_accumulator.HeaderRecord]
       for blockNumber in startNumber .. endNumber:
         let
-          (header, body, totalDifficulty) = (
+          (header, body, totalDifficultyOpt) = (
             waitFor noCancel(client.getBlockByNumber(blockId(blockNumber)))
           ).valueOr:
             error "Failed retrieving block, skip creation of era1 file",
@@ -121,6 +121,10 @@ proc cmdExportEra1(config: ExporterConf) =
             error "Failed retrieving receipts, skip creation of era1 file",
               blockNumber, error
             break writeFileBlock
+          totalDifficulty = totalDifficultyOpt.valueOr:
+            error "Pre-merge block request failed returning total difficulty, era1 file will not be fully valid",
+              blockNumber
+            0.u256
 
         headerRecords.add(
           historical_hashes_accumulator.HeaderRecord(