Abort block building and sending upon commit of an epoch sealing block

common/msg.go

@@ -25,6 +25,21 @@ type Message struct {
 	BlockDigestRequest          *BlockDigestRequest
 }
 
+func (m *Message) IsReplicationMessage() bool {
+	switch {
+	case m.ReplicationResponse != nil:
+		return true
+	case m.ReplicationRequest != nil:
+		return true
+	case m.VerifiedReplicationResponse != nil:
+		return true
+	case m.BlockDigestRequest != nil:
+		return true
+	default:
+		return false
+	}
+}
+
 type EmptyVoteMetadata struct {
 	Round uint64
 	Epoch uint64

common/msg_test.go

@@ -1,3 +1,6 @@
+// Copyright (C) 2019-2025, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
 package common_test
 
 import (
@@ -9,6 +12,96 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestIsReplicationMessage(t *testing.T) {
+	tests := []struct {
+		name     string
+		msg      common.Message
+		expected bool
+	}{
+		{
+			name:     "empty message",
+			msg:      common.Message{},
+			expected: false,
+		},
+		{
+			name:     "replication request",
+			msg:      common.Message{ReplicationRequest: &common.ReplicationRequest{}},
+			expected: true,
+		},
+		{
+			name:     "replication response",
+			msg:      common.Message{ReplicationResponse: &common.ReplicationResponse{}},
+			expected: true,
+		},
+		{
+			name:     "verified replication response",
+			msg:      common.Message{VerifiedReplicationResponse: &common.VerifiedReplicationResponse{}},
+			expected: true,
+		},
+		{
+			name:     "block message",
+			msg:      common.Message{BlockMessage: &common.BlockMessage{}},
+			expected: false,
+		},
+		{
+			name:     "verified block message",
+			msg:      common.Message{VerifiedBlockMessage: &common.VerifiedBlockMessage{}},
+			expected: false,
+		},
+		{
+			name:     "empty notarization",
+			msg:      common.Message{EmptyNotarization: &common.EmptyNotarization{}},
+			expected: false,
+		},
+		{
+			name:     "vote",
+			msg:      common.Message{VoteMessage: &common.Vote{}},
+			expected: false,
+		},
+		{
+			name:     "empty vote",
+			msg:      common.Message{EmptyVoteMessage: &common.EmptyVote{}},
+			expected: false,
+		},
+		{
+			name:     "notarization",
+			msg:      common.Message{Notarization: &common.Notarization{}},
+			expected: false,
+		},
+		{
+			name:     "finalize vote",
+			msg:      common.Message{FinalizeVote: &common.FinalizeVote{}},
+			expected: false,
+		},
+		{
+			name:     "finalization",
+			msg:      common.Message{Finalization: &common.Finalization{}},
+			expected: false,
+		},
+		{
+			// A block digest request is a request but not a replication message.
+			name:     "block digest request",
+			msg:      common.Message{BlockDigestRequest: &common.BlockDigestRequest{}},
+			expected: true,
+		},
+		{
+			// When several fields are set, any replication field makes it a replication message.
+			name: "block message and replication request",
+			msg: common.Message{
+				BlockMessage:       &common.BlockMessage{},
+				ReplicationRequest: &common.ReplicationRequest{},
+			},
+			expected: true,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			require.Equal(t, test.expected, test.msg.IsReplicationMessage())
+		})
+	}
+}
+
 func TestQuorumRoundMalformed(t *testing.T) {
 	tests := []struct {
 		name        string