multi: add itest testSweepAnchorCPFPLocalForceClose

This commit adds an itest case that focuses on validating the CPFP logic
in anchor sweeping.

sweep/fee_bumper.go

@@ -508,7 +508,8 @@ func (t *TxPublisher) createAndCheckTx(req *BumpRequest, f FeeFunction) (
 		return tx, fee, nil
 	}
 
-	return nil, 0, err
+	return nil, 0, fmt.Errorf("tx=%v failed mempool check: %w", tx.TxHash(),
+		err)
 }
 
 // broadcast takes a monitored tx and publishes it to the network. Prior to the
@@ -852,7 +853,7 @@ func (t *TxPublisher) createAndPublishTx(requestID uint64,
 	// directly here.
 	tx, fee, err := t.createAndCheckTx(r.req, r.feeFunction)
 
-	// If the error is fee related, we will return an error and let the fee
+	// If the error is fee related, we will return no error and let the fee
 	// bumper retry it at next block.
 	//
 	// NOTE: we can check the RBF error here and ask the fee function to
@@ -912,6 +913,18 @@ func (t *TxPublisher) createAndPublishTx(requestID uint64,
 		return fn.None[BumpResult]()
 	}
 
+	// If the result error is fee related, we will return no error and let
+	// the fee bumper retry it at next block.
+	//
+	// NOTE: we may get this error if we've bypassed the mempool check,
+	// which means we are suing neutrino backend.
+	if errors.Is(result.Err, rpcclient.ErrInsufficientFee) ||
+		errors.Is(result.Err, lnwallet.ErrMempoolFee) {
+
+		log.Debugf("Failed to bump tx %v: %v", oldTx.TxHash(), err)
+		return fn.None[BumpResult]()
+	}
+
 	// A successful replacement tx is created, attach the old tx.
 	result.ReplacedTx = oldTx
 

sweep/sweeper.go

@@ -931,7 +931,8 @@ func (s *UtxoSweeper) markInputsPublished(tr *TxRecord,
 
 		// Valdiate that the input is in an expected state.
 		if pi.state != PendingPublish {
-			log.Errorf("Expect input %v to have %v, instead it "+
+			// We may get a Published if this is a replacement tx.
+			log.Debugf("Expect input %v to have %v, instead it "+
 				"has %v", input.PreviousOutPoint,
 				PendingPublish, pi.state)