Update the AcceptChannel message for Taproot support.

Author: arik-so

lightning/src/ln/channel.rs

@@ -5332,6 +5332,8 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 				None => Builder::new().into_script(),
 			}),
 			channel_type: Some(self.channel_type.clone()),
+			#[cfg(taproot)]
+			next_local_nonce: None,
 		}
 	}
 

lightning/src/ln/msgs.rs

@@ -249,6 +249,9 @@ pub struct AcceptChannel {
 	/// our feature bits with our counterparty's feature bits from the [`Init`] message.
 	/// This is required to match the equivalent field in [`OpenChannel::channel_type`].
 	pub channel_type: Option<ChannelTypeFeatures>,
+	#[cfg(taproot)]
+	/// Next nonce the channel initiator should use to create a funding output signature against
+	pub next_local_nonce: Option<musig2::types::PublicNonce>,
 }
 
 /// A [`funding_created`] message to be sent to or received from a peer.
@@ -1293,7 +1296,28 @@ impl Readable for OptionalField<u64> {
 	}
 }
 
+#[cfg(not(taproot))]
+impl_writeable_msg!(AcceptChannel, {
+	temporary_channel_id,
+	dust_limit_satoshis,
+	max_htlc_value_in_flight_msat,
+	channel_reserve_satoshis,
+	htlc_minimum_msat,
+	minimum_depth,
+	to_self_delay,
+	max_accepted_htlcs,
+	funding_pubkey,
+	revocation_basepoint,
+	payment_point,
+	delayed_payment_basepoint,
+	htlc_basepoint,
+	first_per_commitment_point,
+	shutdown_scriptpubkey
+}, {
+	(1, channel_type, option),
+});
 
+#[cfg(taproot)]
 impl_writeable_msg!(AcceptChannel, {
 	temporary_channel_id,
 	dust_limit_satoshis,
@@ -1312,6 +1336,7 @@ impl_writeable_msg!(AcceptChannel, {
 	shutdown_scriptpubkey
 }, {
 	(1, channel_type, option),
+	(4, next_local_nonce, option),
 });
 
 impl_writeable_msg!(AnnouncementSignatures, {
@@ -2449,6 +2474,8 @@ mod tests {
 			first_per_commitment_point: pubkey_6,
 			shutdown_scriptpubkey: if shutdown { OptionalField::Present(Address::p2pkh(&::bitcoin::PublicKey{compressed: true, inner: pubkey_1}, Network::Testnet).script_pubkey()) } else { OptionalField::Absent },
 			channel_type: None,
+			#[cfg(taproot)]
+			next_local_nonce: None,
 		};
 		let encoded_value = accept_channel.encode();
 		let mut target_value = hex::decode("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").unwrap();