Respond With Empty Payloads Pre-Merge (#11184)

* regression test

* build

* nil check

* fix test

* gazelle

* lint

beacon-chain/execution/BUILD.bazel

@@ -38,6 +38,7 @@ go_library(
         "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/state/v1:go_default_library",
         "//config/features:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",

beacon-chain/execution/engine_client.go

@@ -13,6 +13,7 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/holiman/uint256"
 	"github.com/pkg/errors"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
@@ -329,6 +330,17 @@ func (s *Service) ReconstructFullBellatrixBlock(
 	if err != nil {
 		return nil, err
 	}
+	if header.IsNil() {
+		return nil, errors.New("execution payload header in blinded block was nil")
+	}
+
+	// If the payload header has a block hash of 0x0, it means we are pre-merge and should
+	// simply return the block with an empty execution payload.
+	if bytes.Equal(header.BlockHash(), params.BeaconConfig().ZeroHash[:]) {
+		payload := buildEmptyExecutionPayload()
+		return blocks.BuildSignedBeaconBlockFromExecutionPayload(blindedBlock, payload)
+	}
+
 	executionBlockHash := common.BytesToHash(header.BlockHash())
 	executionBlock, err := s.ExecutionBlockByHash(ctx, executionBlockHash, true /* with txs */)
 	if err != nil {
@@ -460,3 +472,18 @@ func tDStringToUint256(td string) (*uint256.Int, error) {
 	}
 	return i, nil
 }
+
+func buildEmptyExecutionPayload() *pb.ExecutionPayload {
+	return &pb.ExecutionPayload{
+		ParentHash:    make([]byte, fieldparams.RootLength),
+		FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
+		StateRoot:     make([]byte, fieldparams.RootLength),
+		ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+		LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
+		PrevRandao:    make([]byte, fieldparams.RootLength),
+		BaseFeePerGas: make([]byte, fieldparams.RootLength),
+		BlockHash:     make([]byte, fieldparams.RootLength),
+		Transactions:  make([][]byte, 0),
+		ExtraData:     make([]byte, 0),
+	}
+}

beacon-chain/execution/engine_client_test.go

@@ -420,6 +420,22 @@ func TestReconstructFullBellatrixBlock(t *testing.T) {
 		_, err = service.ReconstructFullBellatrixBlock(ctx, wrapped)
 		require.ErrorContains(t, want, err)
 	})
+	t.Run("pre-merge execution payload", func(t *testing.T) {
+		service := &Service{}
+		bellatrixBlock := util.NewBlindedBeaconBlockBellatrix()
+		wanted := util.NewBeaconBlockBellatrix()
+		wanted.Block.Slot = 1
+		// Make sure block hash is the zero hash.
+		bellatrixBlock.Block.Body.ExecutionPayloadHeader.BlockHash = make([]byte, 32)
+		bellatrixBlock.Block.Slot = 1
+		wrapped, err := blocks.NewSignedBeaconBlock(bellatrixBlock)
+		require.NoError(t, err)
+		wantedWrapped, err := blocks.NewSignedBeaconBlock(wanted)
+		require.NoError(t, err)
+		reconstructed, err := service.ReconstructFullBellatrixBlock(ctx, wrapped)
+		require.NoError(t, err)
+		require.DeepEqual(t, wantedWrapped, reconstructed)
+	})
 	t.Run("properly reconstructs block with correct payload", func(t *testing.T) {
 		fix := fixtures()
 		payload, ok := fix["ExecutionPayload"].(*pb.ExecutionPayload)

consensus-types/blocks/BUILD.bazel

@@ -40,6 +40,7 @@ go_test(
         "//config/fieldparams:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//encoding/bytesutil:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/validator-client:go_default_library",

consensus-types/blocks/factory.go

@@ -154,20 +154,30 @@ func BuildSignedBeaconBlockFromExecutionPayload(
 		return nil, errors.Wrap(err, "could not get execution payload header")
 	default:
 	}
-	payloadRoot, err := payload.HashTreeRoot()
+	wrappedPayload, err := WrappedExecutionPayload(payload)
 	if err != nil {
-		return nil, errors.Wrap(err, "could not hash tree root execution payload")
+		return nil, err
 	}
-	payloadHeaderRoot, err := payloadHeader.HashTreeRoot()
+	empty, err := IsEmptyExecutionData(wrappedPayload)
 	if err != nil {
-		return nil, errors.Wrap(err, "could not hash tree root payload header")
+		return nil, err
 	}
-	if payloadRoot != payloadHeaderRoot {
-		return nil, fmt.Errorf(
-			"payload %#x and header %#x roots do not match",
-			payloadRoot,
-			payloadHeaderRoot,
-		)
+	if !empty {
+		payloadRoot, err := payload.HashTreeRoot()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not hash tree root execution payload")
+		}
+		payloadHeaderRoot, err := payloadHeader.HashTreeRoot()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not hash tree root payload header")
+		}
+		if payloadRoot != payloadHeaderRoot {
+			return nil, fmt.Errorf(
+				"payload %#x and header %#x roots do not match",
+				payloadRoot,
+				payloadHeaderRoot,
+			)
+		}
 	}
 	syncAgg, err := b.Body().SyncAggregate()
 	if err != nil {

consensus-types/blocks/factory_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	enginev1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
 	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/runtime/version"
@@ -241,6 +242,7 @@ func TestBuildSignedBeaconBlockFromExecutionPayload(t *testing.T) {
 		require.Equal(t, true, errors.Is(err, ErrUnsupportedGetter))
 	})
 	t.Run("payload header root and payload root mismatch", func(t *testing.T) {
+		blockHash := bytesutil.Bytes32(1)
 		payload := &enginev1.ExecutionPayload{
 			ParentHash:    make([]byte, fieldparams.RootLength),
 			FeeRecipient:  make([]byte, 20),
@@ -249,7 +251,7 @@ func TestBuildSignedBeaconBlockFromExecutionPayload(t *testing.T) {
 			LogsBloom:     make([]byte, 256),
 			PrevRandao:    make([]byte, fieldparams.RootLength),
 			BaseFeePerGas: make([]byte, fieldparams.RootLength),
-			BlockHash:     make([]byte, fieldparams.RootLength),
+			BlockHash:     blockHash,
 			Transactions:  make([][]byte, 0),
 		}
 		wrapped, err := WrappedExecutionPayload(payload)

testing/util/block.go

@@ -749,6 +749,8 @@ func HydrateBeaconBlockBodyBellatrix(b *ethpb.BeaconBlockBodyBellatrix) *ethpb.B
 			PrevRandao:    make([]byte, fieldparams.RootLength),
 			BaseFeePerGas: make([]byte, fieldparams.RootLength),
 			BlockHash:     make([]byte, fieldparams.RootLength),
+			Transactions:  make([][]byte, 0),
+			ExtraData:     make([]byte, 0),
 		}
 	}
 	return b
@@ -815,6 +817,7 @@ func HydrateBlindedBeaconBlockBodyBellatrix(b *ethpb.BlindedBeaconBlockBodyBella
 			BaseFeePerGas:    make([]byte, 32),
 			BlockHash:        make([]byte, 32),
 			TransactionsRoot: make([]byte, fieldparams.RootLength),
+			ExtraData:        make([]byte, 0),
 		}
 	}
 	return b