eth/catalyst: allow payload attributes v1 in fcu v2 (#28882)

At some point, `ForkchoiceUpdatedV2` stopped working for `PayloadAttributesV1` while `paris` was active. This was causing a few failures in hive. This PR fixes that, and also adds a gate in `ForkchoiceUpdatedV1` to disallow `PayloadAttributesV3`.

eth/catalyst/api.go

@@ -173,8 +173,8 @@ func newConsensusAPIWithoutHeartbeat(eth *eth.Ethereum) *ConsensusAPI {
 // and return its payloadID.
 func (api *ConsensusAPI) ForkchoiceUpdatedV1(update engine.ForkchoiceStateV1, payloadAttributes *engine.PayloadAttributes) (engine.ForkChoiceResponse, error) {
 	if payloadAttributes != nil {
-		if payloadAttributes.Withdrawals != nil {
+		if payloadAttributes.Withdrawals != nil || payloadAttributes.BeaconRoot != nil {
-			return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("withdrawals not supported in V1"))
+			return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("withdrawals and beacon root not supported in V1"))
 		}
 		if api.eth.BlockChain().Config().IsShanghai(api.eth.BlockChain().Config().LondonBlock, payloadAttributes.Timestamp) {
 			return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("forkChoiceUpdateV1 called post-shanghai"))
@@ -183,23 +183,31 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV1(update engine.ForkchoiceStateV1, pa
 	return api.forkchoiceUpdated(update, payloadAttributes, engine.PayloadV1, false)
 }
 
-// ForkchoiceUpdatedV2 is equivalent to V1 with the addition of withdrawals in the payload attributes.
+// ForkchoiceUpdatedV2 is equivalent to V1 with the addition of withdrawals in the payload
+// attributes. It supports both PayloadAttributesV1 and PayloadAttributesV2.
 func (api *ConsensusAPI) ForkchoiceUpdatedV2(update engine.ForkchoiceStateV1, params *engine.PayloadAttributes) (engine.ForkChoiceResponse, error) {
 	if params != nil {
-		if params.Withdrawals == nil {
+		switch api.eth.BlockChain().Config().LatestFork(params.Timestamp) {
-			return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("missing withdrawals"))
+		case forks.Paris:
+			if params.Withdrawals != nil {
+				return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("withdrawals before shanghai"))
+			}
+		case forks.Shanghai:
+			if params.Withdrawals == nil {
+				return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("missing withdrawals"))
+			}
+		default:
+			return engine.STATUS_INVALID, engine.UnsupportedFork.With(errors.New("forkchoiceUpdatedV2 must only be called with paris and shanghai payloads"))
 		}
 		if params.BeaconRoot != nil {
 			return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("unexpected beacon root"))
 		}
-		if api.eth.BlockChain().Config().LatestFork(params.Timestamp) != forks.Shanghai {
-			return engine.STATUS_INVALID, engine.UnsupportedFork.With(errors.New("forkchoiceUpdatedV2 must only be called for shanghai payloads"))
-		}
 	}
 	return api.forkchoiceUpdated(update, params, engine.PayloadV2, false)
 }
 
-// ForkchoiceUpdatedV3 is equivalent to V2 with the addition of parent beacon block root in the payload attributes.
+// ForkchoiceUpdatedV3 is equivalent to V2 with the addition of parent beacon block root
+// in the payload attributes. It supports only PayloadAttributesV3.
 func (api *ConsensusAPI) ForkchoiceUpdatedV3(update engine.ForkchoiceStateV1, params *engine.PayloadAttributes) (engine.ForkChoiceResponse, error) {
 	if params != nil {
 		// TODO(matt): according to https://github.com/ethereum/execution-apis/pull/498,