Cancel back outgoing dust htlcs before commitment is confirmed.

contractcourt/briefcase.go

@@ -1475,16 +1475,23 @@ func decodeBreachResolution(r io.Reader, b *BreachResolution) error {
 	return binary.Read(r, endian, &b.FundingOutPoint.Index)
 }
 
-func encodeHtlcSetKey(w io.Writer, h *HtlcSetKey) error {
-	err := binary.Write(w, endian, h.IsRemote)
+func encodeHtlcSetKey(w io.Writer, htlcSetKey HtlcSetKey) error {
+	err := binary.Write(w, endian, htlcSetKey.IsRemote)
 	if err != nil {
 		return err
 	}
-	return binary.Write(w, endian, h.IsPending)
+
+	return binary.Write(w, endian, htlcSetKey.IsPending)
 }
 
 func encodeCommitSet(w io.Writer, c *CommitSet) error {
-	if err := encodeHtlcSetKey(w, c.ConfCommitKey); err != nil {
+	confCommitKey, err := c.ConfCommitKey.UnwrapOrErr(
+		fmt.Errorf("HtlcSetKey is not set"),
+	)
+	if err != nil {
+		return err
+	}
+	if err := encodeHtlcSetKey(w, confCommitKey); err != nil {
 		return err
 	}
 
@@ -1494,8 +1501,7 @@ func encodeCommitSet(w io.Writer, c *CommitSet) error {
 	}
 
 	for htlcSetKey, htlcs := range c.HtlcSets {
-		htlcSetKey := htlcSetKey
-		if err := encodeHtlcSetKey(w, &htlcSetKey); err != nil {
+		if err := encodeHtlcSetKey(w, htlcSetKey); err != nil {
 			return err
 		}
 
@@ -1517,13 +1523,14 @@ func decodeHtlcSetKey(r io.Reader, h *HtlcSetKey) error {
 }
 
 func decodeCommitSet(r io.Reader) (*CommitSet, error) {
-	c := &CommitSet{
-		ConfCommitKey: &HtlcSetKey{},
-		HtlcSets:      make(map[HtlcSetKey][]channeldb.HTLC),
+	confCommitKey := HtlcSetKey{}
+	if err := decodeHtlcSetKey(r, &confCommitKey); err != nil {
+		return nil, err
 	}
 
-	if err := decodeHtlcSetKey(r, c.ConfCommitKey); err != nil {
-		return nil, err
+	c := &CommitSet{
+		ConfCommitKey: fn.Some(confCommitKey),
+		HtlcSets:      make(map[HtlcSetKey][]channeldb.HTLC),
 	}
 
 	var numSets uint8

contractcourt/briefcase_test.go

@@ -14,6 +14,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/davecgh/go-spew/spew"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/kvdb"
 	"github.com/lightningnetwork/lnd/lnmock"
@@ -753,7 +754,7 @@ func TestCommitSetStorage(t *testing.T) {
 	for _, pendingRemote := range []bool{true, false} {
 		for _, confType := range confTypes {
 			commitSet := &CommitSet{
-				ConfCommitKey: &confType,
+				ConfCommitKey: fn.Some(confType),
 				HtlcSets:      make(map[HtlcSetKey][]channeldb.HTLC),
 			}
 			commitSet.HtlcSets[LocalHtlcSet] = activeHTLCs

contractcourt/chain_watcher.go

@@ -93,9 +93,9 @@ type BreachCloseInfo struct {
 // HTLCs to determine if any additional actions need to be made based on the
 // remote party's commitments.
 type CommitSet struct {
-	// ConfCommitKey if non-nil, identifies the commitment that was
+	// When the ConfCommitKey is set, it signals that the commitment tx was
 	// confirmed in the chain.
-	ConfCommitKey *HtlcSetKey
+	ConfCommitKey fn.Option[HtlcSetKey]
 
 	// HtlcSets stores the set of all known active HTLC for each active
 	// commitment at the time of channel closure.
@@ -509,7 +509,7 @@ func (c *chainWatcher) handleUnknownLocalState(
 
 	// If this is our commitment transaction, then we try to act even
 	// though we won't be able to sweep HTLCs.
-	chainSet.commitSet.ConfCommitKey = &LocalHtlcSet
+	chainSet.commitSet.ConfCommitKey = fn.Some(LocalHtlcSet)
 	if err := c.dispatchLocalForceClose(
 		commitSpend, broadcastStateNum, chainSet.commitSet,
 	); err != nil {
@@ -806,7 +806,7 @@ func (c *chainWatcher) handleKnownLocalState(
 		return false, nil
 	}
 
-	chainSet.commitSet.ConfCommitKey = &LocalHtlcSet
+	chainSet.commitSet.ConfCommitKey = fn.Some(LocalHtlcSet)
 	if err := c.dispatchLocalForceClose(
 		commitSpend, broadcastStateNum, chainSet.commitSet,
 	); err != nil {
@@ -844,7 +844,7 @@ func (c *chainWatcher) handleKnownRemoteState(
 		log.Infof("Remote party broadcast base set, "+
 			"commit_num=%v", chainSet.remoteStateNum)
 
-		chainSet.commitSet.ConfCommitKey = &RemoteHtlcSet
+		chainSet.commitSet.ConfCommitKey = fn.Some(RemoteHtlcSet)
 		err := c.dispatchRemoteForceClose(
 			commitSpend, chainSet.remoteCommit,
 			chainSet.commitSet,
@@ -869,7 +869,7 @@ func (c *chainWatcher) handleKnownRemoteState(
 		log.Infof("Remote party broadcast pending set, "+
 			"commit_num=%v", chainSet.remoteStateNum+1)
 
-		chainSet.commitSet.ConfCommitKey = &RemotePendingHtlcSet
+		chainSet.commitSet.ConfCommitKey = fn.Some(RemotePendingHtlcSet)
 		err := c.dispatchRemoteForceClose(
 			commitSpend, *chainSet.remotePendingCommit,
 			chainSet.commitSet,
@@ -936,7 +936,7 @@ func (c *chainWatcher) handlePossibleBreach(commitSpend *chainntnfs.SpendDetail,
 	// only used to ensure a nil-pointer-dereference doesn't occur and is
 	// not used otherwise. The HTLC's may not exist for the
 	// RemotePendingHtlcSet.
-	chainSet.commitSet.ConfCommitKey = &RemoteHtlcSet
+	chainSet.commitSet.ConfCommitKey = fn.Some(RemoteHtlcSet)
 
 	// THEY'RE ATTEMPTING TO VIOLATE THE CONTRACT LAID OUT WITHIN THE
 	// PAYMENT CHANNEL. Therefore we close the signal indicating a revoked
@@ -997,7 +997,7 @@ func (c *chainWatcher) handleUnknownRemoteState(
 	// means we won't be able to recover any HTLC funds.
 	//
 	// TODO(halseth): can we try to recover some HTLCs?
-	chainSet.commitSet.ConfCommitKey = &RemoteHtlcSet
+	chainSet.commitSet.ConfCommitKey = fn.Some(RemoteHtlcSet)
 	err := c.dispatchRemoteForceClose(
 		commitSpend, channeldb.ChannelCommitment{},
 		chainSet.commitSet, commitPoint,