Minor adjustment to fee rate handling in RBF fee bumping

Use user-provided fee rate for bumping transaction and return an error if
it is too low, otherwise use system estimated fee rate and retry mechanism.

Also adds a test for the low-fee rejection provided by user, switches the
RBF test to use `random_chain_source`, and removes unnecessary sleep-based
waits.

Author: Camillarhi

src/wallet/mod.rs

@@ -378,8 +378,8 @@ impl Wallet {
 					);
 					let payment =
 						self.payment_store.get(&payment_id).ok_or(Error::InvalidPaymentId)?;
-					let pending_payment_details = self
-						.create_pending_payment_from_tx(payment.clone(), conflict_txids.clone());
+					let pending_payment_details =
+						self.create_pending_payment_from_tx(payment, conflict_txids.clone());
 
 					self.pending_payment_store.insert_or_update(pending_payment_details)?;
 				},
@@ -1125,13 +1125,13 @@ impl Wallet {
 			old_fee_rate.to_sat_per_kwu() + INCREMENTAL_RELAY_FEE_SAT_PER_1000_WEIGHT as u64;
 
 		let confirmation_target = ConfirmationTarget::OnchainPayment;
-		let estimated_fee_rate =
-			fee_rate.unwrap_or_else(|| self.fee_estimator.estimate_fee_rate(confirmation_target));
+		let estimated_fee_rate = self.fee_estimator.estimate_fee_rate(confirmation_target);
 
 		// Use the higher of minimum RBF requirement or current network estimate
 		let final_fee_rate_sat_per_kwu =
 			min_required_fee_rate_sat_per_kwu.max(estimated_fee_rate.to_sat_per_kwu());
-		let final_fee_rate = FeeRate::from_sat_per_kwu(final_fee_rate_sat_per_kwu);
+		let final_fee_rate =
+			fee_rate.unwrap_or_else(|| FeeRate::from_sat_per_kwu(final_fee_rate_sat_per_kwu));
 
 		let mut psbt = {
 			let mut builder = locked_wallet.build_fee_bump(txid).map_err(|e| {
@@ -1156,6 +1156,17 @@ impl Wallet {
 			match builder.finish() {
 				Ok(psbt) => Ok(psbt),
 				Err(CreateTxError::FeeRateTooLow { required: required_fee_rate }) => {
+					if fee_rate.is_some() {
+						log_error!(
+							self.logger,
+							"Provided fee rate {} is too low for RBF fee bump of txid {}, required minimum fee rate: {}",
+							fee_rate.unwrap(),
+							txid,
+							required_fee_rate
+						);
+						return Err(Error::InvalidFeeRate);
+					}
+
 					log_info!(self.logger, "BDK requires higher fee rate: {}", required_fee_rate);
 
 					// BDK may require a higher fee rate than our estimate due to

tests/integration_tests_rust.rs

@@ -2466,7 +2466,7 @@ async fn persistence_backwards_compatibility() {
 #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
 async fn onchain_fee_bump_rbf() {
 	let (bitcoind, electrsd) = setup_bitcoind_and_electrsd();
-	let chain_source = TestChainSource::Esplora(&electrsd);
+	let chain_source = random_chain_source(&bitcoind, &electrsd);
 	let (node_a, node_b) = setup_two_nodes(&chain_source, false, true, false);
 
 	// Fund both nodes
@@ -2516,9 +2516,6 @@ async fn onchain_fee_bump_rbf() {
 	let new_txid = node_b.onchain_payment().bump_fee_rbf(payment_id, None).unwrap();
 	wait_for_tx(&electrsd.client, new_txid).await;
 
-	// Sleep to allow for transaction propagation
-	tokio::time::sleep(std::time::Duration::from_secs(5)).await;
-
 	node_a.sync_wallets().unwrap();
 	node_b.sync_wallets().unwrap();
 
@@ -2557,9 +2554,6 @@ async fn onchain_fee_bump_rbf() {
 	let second_bump_txid = node_b.onchain_payment().bump_fee_rbf(payment_id, None).unwrap();
 	wait_for_tx(&electrsd.client, second_bump_txid).await;
 
-	// Sleep to allow for transaction propagation
-	tokio::time::sleep(std::time::Duration::from_secs(5)).await;
-
 	node_a.sync_wallets().unwrap();
 	node_b.sync_wallets().unwrap();