Detect duplicate BOLT11 invoices

Outbound BOLT11 payments now use random payment IDs.

A payment ID lookup no longer catches same-invoice retries.

Scan outbound BOLT11 records by payment hash instead.

Reject pending or succeeded matches while allowing failed retries.

Co-Authored-By: HAL 9000

Author: tnull

src/payment/bolt11.rs

@@ -203,6 +203,17 @@ mod tests {
 }
 
 impl Bolt11Payment {
+	fn has_pending_or_succeeded_outbound_payment(&self, payment_hash: &PaymentHash) -> bool {
+		!self
+			.payment_store
+			.list_filter(|payment| {
+				payment.direction == PaymentDirection::Outbound
+					&& matches!(&payment.kind, PaymentKind::Bolt11 { hash, .. } if hash == payment_hash)
+					&& matches!(payment.status, PaymentStatus::Pending | PaymentStatus::Succeeded)
+			})
+			.is_empty()
+	}
+
 	fn send_internal(
 		&self, invoice: &LdkBolt11Invoice, amount_msat: Option<u64>,
 		route_parameters: Option<RouteParametersConfig>,
@@ -213,16 +224,12 @@ impl Bolt11Payment {
 		}
 
 		let payment_hash = invoice.payment_hash();
+		if self.has_pending_or_succeeded_outbound_payment(&payment_hash) {
+			log_error!(self.logger, "Payment error: an invoice must not be paid twice.");
+			return Err(Error::DuplicatePayment);
+		}
+
 		let payment_id = PaymentId(self.keys_manager.get_secure_random_bytes());
-		// TODO: re-add checking for duplicate payments?
-		//if let Some(payment) = self.payment_store.get(&payment_id) {
-		//	if payment.status == PaymentStatus::Pending
-		//		|| payment.status == PaymentStatus::Succeeded
-		//	{
-		//		log_error!(self.logger, "Payment error: an invoice must not be paid twice.");
-		//		return Err(Error::DuplicatePayment);
-		//	}
-		//}
 
 		let route_params_config =
 			route_parameters.or(self.config.route_parameters).unwrap_or_default();