f - DRY

Author: jkczyz

lightning/src/ln/channel.rs

@@ -10847,6 +10847,32 @@ where
 		}
 
 		let their_funding_contribution = SignedAmount::from_sat(msg.funding_contribution_satoshis);
+		self.validate_splice_contribution(their_funding_contribution)?;
+
+		// TODO(splicing): Check that channel balance does not go below the channel reserve
+
+		let splice_funding = FundingScope::for_splice(
+			&self.funding,
+			&self.context,
+			our_funding_contribution,
+			their_funding_contribution,
+			msg.funding_pubkey,
+		)?;
+
+		// TODO(splicing): Once splice acceptor can contribute, check that inputs are sufficient,
+		// similarly to the check in `splice_channel`.
+
+		// Note on channel reserve requirement pre-check: as the splice acceptor does not contribute,
+		// it can't go below reserve, therefore no pre-check is done here.
+
+		// TODO(splicing): Early check for reserve requirement
+
+		Ok(splice_funding)
+	}
+
+	fn validate_splice_contribution(
+		&self, their_funding_contribution: SignedAmount,
+	) -> Result<(), ChannelError> {
 		if their_funding_contribution > SignedAmount::MAX_MONEY {
 			return Err(ChannelError::WarnAndDisconnect(format!(
 				"Channel {} cannot be spliced in; their {} contribution exceeds the total bitcoin supply",
@@ -10879,25 +10905,7 @@ where
 			)));
 		}
 
-		// TODO(splicing): Check that channel balance does not go below the channel reserve
-
-		let splice_funding = FundingScope::for_splice(
-			&self.funding,
-			&self.context,
-			our_funding_contribution,
-			their_funding_contribution,
-			msg.funding_pubkey,
-		)?;
-
-		// TODO(splicing): Once splice acceptor can contribute, check that inputs are sufficient,
-		// similarly to the check in `splice_channel`.
-
-		// Note on channel reserve requirement pre-check: as the splice acceptor does not contribute,
-		// it can't go below reserve, therefore no pre-check is done here.
-
-		// TODO(splicing): Early check for reserve requirement
-
-		Ok(splice_funding)
+		Ok(())
 	}
 
 	/// See also [`validate_splice_init`]
@@ -11013,37 +11021,7 @@ where
 		debug_assert!(our_funding_contribution <= SignedAmount::MAX_MONEY);
 
 		let their_funding_contribution = SignedAmount::from_sat(msg.funding_contribution_satoshis);
-		if their_funding_contribution > SignedAmount::MAX_MONEY {
-			return Err(ChannelError::WarnAndDisconnect(format!(
-				"Channel {} cannot be spliced in; their {} contribution exceeds the total bitcoin supply",
-				self.context.channel_id(),
-				their_funding_contribution,
-			)));
-		}
-
-		if their_funding_contribution < -SignedAmount::MAX_MONEY {
-			return Err(ChannelError::WarnAndDisconnect(format!(
-				"Channel {} cannot be spliced out; their {} contribution exhausts the total bitcoin supply",
-				self.context.channel_id(),
-				their_funding_contribution,
-			)));
-		}
-
-		let their_channel_balance = Amount::from_sat(self.funding.get_value_satoshis())
-			- Amount::from_sat(self.funding.get_value_to_self_msat() / 1000);
-		let post_channel_balance = AddSigned::checked_add_signed(
-			their_channel_balance.to_sat(),
-			their_funding_contribution.to_sat(),
-		);
-
-		if post_channel_balance.is_none() {
-			return Err(ChannelError::WarnAndDisconnect(format!(
-				"Channel {} cannot be spliced out; their {} contribution exhausts their channel balance: {}",
-				self.context.channel_id(),
-				their_funding_contribution,
-				their_channel_balance,
-			)));
-		}
+		self.validate_splice_contribution(their_funding_contribution)?;
 
 		let splice_funding = FundingScope::for_splice(
 			&self.funding,
@@ -11081,6 +11059,9 @@ where
 		let tx_msg_opt = interactive_tx_constructor.take_initiator_first_message();
 
 		debug_assert!(self.interactive_tx_signing_session.is_none());
+
+		let pending_splice =
+			self.pending_splice.as_mut().expect("pending_splice should still be set");
 		pending_splice.funding_negotiation = Some(FundingNegotiation::ConstructingTransaction(
 			splice_funding,
 			interactive_tx_constructor,