From cae4f43c19fdba1bbd85edb7213c74694b914cc1 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@lightning.engineering>
Date: Wed, 17 Oct 2018 16:21:06 -0700
Subject: [PATCH] sweep/sweeper: ignore unknown witness types

This commit restores the sweep behavior of
filtering inputs with unknown witness types
from the final sweep transaction. Currently,
such inputs will be included without adding
anything to the weight estimate, possibly
creating a transaction with insufficient fees.
---
 sweep/sweeper.go | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/sweep/sweeper.go b/sweep/sweeper.go
index 0bd101b2..a3484614 100644
--- a/sweep/sweeper.go
+++ b/sweep/sweeper.go
@@ -65,14 +65,13 @@ func (s *UtxoSweeper) CreateSweepTx(inputs []Input,
 		return nil, err
 	}
 
-	txWeight, csvCount, cltvCount := s.getWeightEstimate(inputs)
-
 	// Using the txn weight estimate, compute the required txn fee.
 	feePerKw, err := s.cfg.Estimator.EstimateFeePerKW(s.cfg.ConfTarget)
 	if err != nil {
 		return nil, err
 	}
 
+	inputs, txWeight, csvCount, cltvCount := s.getWeightEstimate(inputs)
 	log.Infof("Creating sweep transaction for %v inputs (%v CSV, %v CLTV) "+
 		"using %v sat/kw", len(inputs), csvCount, cltvCount,
 		int64(feePerKw))
@@ -149,7 +148,7 @@ func (s *UtxoSweeper) CreateSweepTx(inputs []Input,
 
 // getWeightEstimate returns a weight estimate for the given inputs.
 // Additionally, it returns counts for the number of csv and cltv inputs.
-func (s *UtxoSweeper) getWeightEstimate(inputs []Input) (int64, int, int) {
+func (s *UtxoSweeper) getWeightEstimate(inputs []Input) ([]Input, int64, int, int) {
 
 	// Create a transaction which sweeps all the newly mature outputs into
 	// an output controlled by the wallet.
@@ -169,6 +168,7 @@ func (s *UtxoSweeper) getWeightEstimate(inputs []Input) (int64, int, int) {
 	csvCount := 0
 	cltvCount := 0
 
+	var sweepInputs []Input
 	for i := range inputs {
 		input := inputs[i]
 
@@ -178,6 +178,7 @@ func (s *UtxoSweeper) getWeightEstimate(inputs []Input) (int64, int, int) {
 		// to us.
 		case lnwallet.CommitmentNoDelay:
 			weightEstimate.AddP2WKHInput()
+			sweepInputs = append(sweepInputs, input)
 
 		// Outputs on a past commitment transaction that pay directly
 		// to us.
@@ -185,6 +186,7 @@ func (s *UtxoSweeper) getWeightEstimate(inputs []Input) (int64, int, int) {
 			weightEstimate.AddWitnessInput(
 				lnwallet.ToLocalTimeoutWitnessSize,
 			)
+			sweepInputs = append(sweepInputs, input)
 			csvCount++
 
 		// Outgoing second layer HTLC's that have confirmed within the
@@ -194,6 +196,7 @@ func (s *UtxoSweeper) getWeightEstimate(inputs []Input) (int64, int, int) {
 			weightEstimate.AddWitnessInput(
 				lnwallet.ToLocalTimeoutWitnessSize,
 			)
+			sweepInputs = append(sweepInputs, input)
 			csvCount++
 
 		// Incoming second layer HTLC's that have confirmed within the
@@ -203,6 +206,7 @@ func (s *UtxoSweeper) getWeightEstimate(inputs []Input) (int64, int, int) {
 			weightEstimate.AddWitnessInput(
 				lnwallet.ToLocalTimeoutWitnessSize,
 			)
+			sweepInputs = append(sweepInputs, input)
 			csvCount++
 
 		// An HTLC on the commitment transaction of the remote party,
@@ -211,6 +215,7 @@ func (s *UtxoSweeper) getWeightEstimate(inputs []Input) (int64, int, int) {
 			weightEstimate.AddWitnessInput(
 				lnwallet.AcceptedHtlcTimeoutWitnessSize,
 			)
+			sweepInputs = append(sweepInputs, input)
 			cltvCount++
 
 		// An HTLC on the commitment transaction of the remote party,
@@ -219,16 +224,16 @@ func (s *UtxoSweeper) getWeightEstimate(inputs []Input) (int64, int, int) {
 			weightEstimate.AddWitnessInput(
 				lnwallet.OfferedHtlcSuccessWitnessSize,
 			)
+			sweepInputs = append(sweepInputs, input)
 
 		default:
 			log.Warnf("kindergarten output in nursery store "+
 				"contains unexpected witness type: %v",
 				input.WitnessType())
-			continue
 		}
 	}
 
 	txWeight := int64(weightEstimate.Weight())
 
-	return txWeight, csvCount, cltvCount
+	return sweepInputs, txWeight, csvCount, cltvCount
 }