lnwire: add local_nonces field to revoke_and_ack

diff --git a/lnwire/revoke_and_ack.go b/lnwire/revoke_and_ack.go
index 3c9775c..676ac01 100644
--- a/lnwire/revoke_and_ack.go
+++ b/lnwire/revoke_and_ack.go
@@ -38,6 +38,10 @@ type RevokeAndAck struct {
 	// remote nonce and the sender's local nonce.
 	LocalNonce OptMusig2NonceTLV
 
+	// LocalNonces is an optional field that stores a map of local musig2
+	// nonces, keyed by TXID. This is used for splice nonce coordination.
+	LocalNonces OptLocalNonces
+
 	// ExtraData is the set of data that was appended to this message to
 	// fill out the full maximum transport message size. These fields can
 	// be used to specify optional data such as custom TLV fields.
@@ -78,8 +82,14 @@ func (c *RevokeAndAck) Decode(r io.Reader, pver uint32) error {
 		return err
 	}
 
-	localNonce := c.LocalNonce.Zero()
-	typeMap, err := tlvRecords.ExtractRecords(&localNonce)
+	var (
+		localNonce      = c.LocalNonce.Zero()
+		localNoncesData LocalNoncesData
+	)
+
+	typeMap, err := tlvRecords.ExtractRecords(
+		&localNonce, &localNoncesData,
+	)
 	if err != nil {
 		return err
 	}
@@ -88,6 +98,9 @@ func (c *RevokeAndAck) Decode(r io.Reader, pver uint32) error {
 	if val, ok := typeMap[c.LocalNonce.TlvType()]; ok && val == nil {
 		c.LocalNonce = tlv.SomeRecordT(localNonce)
 	}
+	if val, ok := typeMap[(LocalNoncesRecordTypeDef)(nil).TypeVal()]; ok && val == nil {
+		c.LocalNonces = SomeLocalNonces(localNoncesData)
+	}
 
 	if len(tlvRecords) != 0 {
 		c.ExtraData = tlvRecords
@@ -101,10 +114,13 @@ func (c *RevokeAndAck) Decode(r io.Reader, pver uint32) error {
 //
 // This is part of the lnwire.Message interface.
 func (c *RevokeAndAck) Encode(w *bytes.Buffer, pver uint32) error {
-	recordProducers := make([]tlv.RecordProducer, 0, 1)
+	recordProducers := make([]tlv.RecordProducer, 0, 2)
 	c.LocalNonce.WhenSome(func(localNonce Musig2NonceTLV) {
 		recordProducers = append(recordProducers, &localNonce)
 	})
+	c.LocalNonces.WhenSome(func(ln LocalNoncesData) {
+		recordProducers = append(recordProducers, &ln)
+	})
 	err := EncodeMessageExtraData(&c.ExtraData, recordProducers...)
 	if err != nil {
 		return err
diff --git a/lnwire/test_message.go b/lnwire/test_message.go
index 0d95db2..5fee057 100644
--- a/lnwire/test_message.go
+++ b/lnwire/test_message.go
@@ -1854,6 +1854,27 @@ func (c *RevokeAndAck) RandTestMessage(t *rapid.T) Message {
 		)
 	}
 
+	if rapid.Bool().Draw(t, "includeLocalNonces") {
+		numNonces := rapid.IntRange(0, 3).Draw(t, "numLocalNonces")
+		nonces := make(map[chainhash.Hash]Musig2Nonce)
+		for i := 0; i < numNonces; i++ {
+			txid := RandChainHash(t)
+
+			// Ensure unique txids for the map.
+			for {
+				_, ok := nonces[txid]
+				if !ok {
+					break
+				}
+				txid = RandChainHash(t)
+			}
+
+			nonces[txid] = RandMusig2Nonce(t)
+		}
+
+		msg.LocalNonces = SomeLocalNonces(LocalNoncesData{NoncesMap: nonces})
+	}
+
 	return msg
 }