f always use v2 derivation for splices

Author: TheBlueMatt

lightning/src/sign/mod.rs

@@ -1451,8 +1451,10 @@ impl ChannelSigner for InMemorySigner {
 	fn new_pubkeys(
 		&self, splice_parent_funding_txid: Option<Txid>, secp_ctx: &Secp256k1<secp256k1::All>,
 	) -> ChannelPublicKeys {
+		let use_v2_derivation =
+			self.v2_remote_key_derivation || splice_parent_funding_txid.is_some();
 		let payment_key =
-			if self.v2_remote_key_derivation { &self.payment_key_v2 } else { &self.payment_key_v1 };
+			if use_v2_derivation { &self.payment_key_v2 } else { &self.payment_key_v1 };
 		let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
 		let mut pubkeys = ChannelPublicKeys {
 			funding_pubkey: from_secret(&self.funding_key.0),