Fix minor issue in blsToExecChange validator (#13498)

Co-authored-by: Nishant Das <nishdas93@gmail.com>

beacon-chain/p2p/message_id.go

@@ -83,7 +83,7 @@ func postAltairMsgID(pmsg *pubsubpb.Message, fEpoch primitives.Epoch) string {
 	decodedData, err := encoder.DecodeSnappy(pmsg.Data, gossipPubSubSize)
 	if err != nil {
 		totalLength, err := math.AddInt(
-			len(params.BeaconConfig().MessageDomainValidSnappy),
+			len(params.BeaconConfig().MessageDomainInvalidSnappy),
 			len(topicLenBytes),
 			topicLen,
 			len(pmsg.Data),

beacon-chain/sync/initial-sync/blocks_fetcher.go

@@ -517,7 +517,7 @@ func (f *blocksFetcher) requestBlobs(ctx context.Context, req *p2ppb.BlobSidecar
 		"capacity": f.rateLimiter.Remaining(pid.String()),
 		"score":    f.p2p.Peers().Scorers().BlockProviderScorer().FormatScorePretty(pid),
 	}).Debug("Requesting blobs")
-	// We're intentionally abusing the block rate limit here, treating blob requests as if they were blob requests.
+	// We're intentionally abusing the block rate limit here, treating blob requests as if they were block requests.
 	// Since blob requests take more bandwidth than blocks, we should improve how we account for the different kinds
 	// of requests, more in proportion to the cost of serving them.
 	if f.rateLimiter.Remaining(pid.String()) < int64(req.Count) {

beacon-chain/sync/validate_bls_to_execution_change.go

@@ -38,6 +38,9 @@ func (s *Service) validateBlsToExecutionChange(ctx context.Context, pid peer.ID,
 	}
 
 	// Check that the validator hasn't submitted a previous execution change.
+	if blsChange.Message == nil {
+		return pubsub.ValidationReject, errNilMessage
+	}
 	if s.cfg.blsToExecPool.ValidatorExists(blsChange.Message.ValidatorIndex) {
 		return pubsub.ValidationIgnore, nil
 	}