Limit the scope of get_funding_created_msg to outbound channels

Since we no longer use `ChannelContext::get_funding_created_msg`,
it can be moved back into `UnfundedOutboundV1` channels only,
where it realistically belongs.

Author: TheBlueMatt

lightning/src/ln/channel.rs

@@ -2176,38 +2176,6 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
 		}
 	}
 
-	/// Only allowed after [`Self::channel_transaction_parameters`] is set.
-	fn get_funding_created_msg<L: Deref>(&mut self, logger: &L) -> Option<msgs::FundingCreated> where L::Target: Logger {
-		let counterparty_keys = self.build_remote_transaction_keys();
-		let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
-		let signature = match &self.holder_signer {
-			// TODO (taproot|arik): move match into calling method for Taproot
-			ChannelSignerType::Ecdsa(ecdsa) => {
-				ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), Vec::new(), &self.secp_ctx)
-					.map(|(sig, _)| sig).ok()?
-			},
-			// TODO (taproot|arik)
-			#[cfg(taproot)]
-			_ => todo!()
-		};
-
-		if self.signer_pending_funding {
-			log_trace!(logger, "Counterparty commitment signature ready for funding_created message: clearing signer_pending_funding");
-			self.signer_pending_funding = false;
-		}
-
-		Some(msgs::FundingCreated {
-			temporary_channel_id: self.temporary_channel_id.unwrap(),
-			funding_txid: self.channel_transaction_parameters.funding_outpoint.as_ref().unwrap().txid,
-			funding_output_index: self.channel_transaction_parameters.funding_outpoint.as_ref().unwrap().index,
-			signature,
-			#[cfg(taproot)]
-			partial_signature_with_nonce: None,
-			#[cfg(taproot)]
-			next_local_nonce: None,
-		})
-	}
-
 	/// Only allowed after [`Self::channel_transaction_parameters`] is set.
 	fn get_funding_signed_msg<L: Deref>(&mut self, logger: &L) -> (CommitmentTransaction, Option<msgs::FundingSigned>) where L::Target: Logger {
 		let counterparty_keys = self.build_remote_transaction_keys();
@@ -6104,6 +6072,38 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 		})
 	}
 
+	/// Only allowed after [`ChannelContext::channel_transaction_parameters`] is set.
+	fn get_funding_created_msg<L: Deref>(&mut self, logger: &L) -> Option<msgs::FundingCreated> where L::Target: Logger {
+		let counterparty_keys = self.context.build_remote_transaction_keys();
+		let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
+		let signature = match &self.context.holder_signer {
+			// TODO (taproot|arik): move match into calling method for Taproot
+			ChannelSignerType::Ecdsa(ecdsa) => {
+				ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), Vec::new(), &self.context.secp_ctx)
+					.map(|(sig, _)| sig).ok()?
+			},
+			// TODO (taproot|arik)
+			#[cfg(taproot)]
+			_ => todo!()
+		};
+
+		if self.context.signer_pending_funding {
+			log_trace!(logger, "Counterparty commitment signature ready for funding_created message: clearing signer_pending_funding");
+			self.context.signer_pending_funding = false;
+		}
+
+		Some(msgs::FundingCreated {
+			temporary_channel_id: self.context.temporary_channel_id.unwrap(),
+			funding_txid: self.context.channel_transaction_parameters.funding_outpoint.as_ref().unwrap().txid,
+			funding_output_index: self.context.channel_transaction_parameters.funding_outpoint.as_ref().unwrap().index,
+			signature,
+			#[cfg(taproot)]
+			partial_signature_with_nonce: None,
+			#[cfg(taproot)]
+			next_local_nonce: None,
+		})
+	}
+
 	/// Updates channel state with knowledge of the funding transaction's txid/index, and generates
 	/// a funding_created message for the remote peer.
 	/// Panics if called at some time other than immediately after initial handshake, if called twice,
@@ -6144,7 +6144,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 		self.context.funding_transaction = Some(funding_transaction);
 		self.context.is_batch_funding = Some(()).filter(|_| is_batch_funding);
 
-		let funding_created = self.context.get_funding_created_msg(logger);
+		let funding_created = self.get_funding_created_msg(logger);
 		if funding_created.is_none() {
 			if !self.context.signer_pending_funding {
 				log_trace!(logger, "funding_created awaiting signer; setting signer_pending_funding");
@@ -6490,7 +6490,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 	pub fn signer_maybe_unblocked<L: Deref>(&mut self, logger: &L) -> Option<msgs::FundingCreated> where L::Target: Logger {
 		if self.context.signer_pending_funding && self.context.is_outbound() {
 			log_trace!(logger, "Signer unblocked a funding_created");
-			self.context.get_funding_created_msg(logger)
+			self.get_funding_created_msg(logger)
 		} else { None }
 	}
 }