From d207654dbd8cb14f195a9f15c44f9f43c1ad8740 Mon Sep 17 00:00:00 2001
From: Justin Florentine <justin+github@florentine.us>
Date: Thu, 5 Oct 2023 17:03:59 -0400
Subject: [PATCH] hive tests explicitly attempt zero

Signed-off-by: Justin Florentine <justin+github@florentine.us>
---
 .../internal/methods/engine/EngineForkchoiceUpdatedV2.java   | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineForkchoiceUpdatedV2.java b/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineForkchoiceUpdatedV2.java
index 44ba15cae8d..e7a3ba9f537 100644
--- a/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineForkchoiceUpdatedV2.java
+++ b/ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineForkchoiceUpdatedV2.java
@@ -58,6 +58,11 @@ protected Optional<JsonRpcErrorResponse> isPayloadAttributesValid(
       final Optional<List<Withdrawal>> maybeWithdrawals,
       final BlockHeader headBlockHeader) {
     if (payloadAttributes.getTimestamp() >= cancunTimestamp) {
+      if (payloadAttributes.getParentBeaconBlockRoot() == null
+          || payloadAttributes.getParentBeaconBlockRoot().isEmpty()
+          || payloadAttributes.getParentBeaconBlockRoot().isZero()) {
+        return Optional.of(new JsonRpcErrorResponse(requestId, RpcErrorType.INVALID_PARAMS));
+      }
       return Optional.of(new JsonRpcErrorResponse(requestId, RpcErrorType.UNSUPPORTED_FORK));
     } else if (payloadAttributes.getParentBeaconBlockRoot() != null) {
       LOG.error(