From 92af2342daaf0cb4220c74794d05cfcf97f20c09 Mon Sep 17 00:00:00 2001
From: "Johan T. Halseth" <johanth@gmail.com>
Date: Fri, 6 Mar 2020 16:11:47 +0100
Subject: [PATCH] lnwallet+nursery+input: set sequence=1 for direct HTLC spends

---
 contractcourt/htlc_success_resolver.go |  1 +
 input/input.go                         | 13 +++++++------
 lnwallet/channel.go                    |  9 ++++++---
 utxonursery.go                         | 10 ++++++----
 utxonursery_test.go                    |  3 ++-
 5 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/contractcourt/htlc_success_resolver.go b/contractcourt/htlc_success_resolver.go
index c13c52e8..38fa7fd0 100644
--- a/contractcourt/htlc_success_resolver.go
+++ b/contractcourt/htlc_success_resolver.go
@@ -118,6 +118,7 @@ func (h *htlcSuccessResolver) Resolve() (ContractResolver, error) {
 				&h.htlcResolution.SweepSignDesc,
 				h.htlcResolution.Preimage[:],
 				h.broadcastHeight,
+				h.htlcResolution.CsvDelay,
 			)
 
 			// With the input created, we can now generate the full
diff --git a/input/input.go b/input/input.go
index 7f5593ec..38a1651e 100644
--- a/input/input.go
+++ b/input/input.go
@@ -156,15 +156,16 @@ type HtlcSucceedInput struct {
 // MakeHtlcSucceedInput assembles a new redeem input that can be used to
 // construct a sweep transaction.
 func MakeHtlcSucceedInput(outpoint *wire.OutPoint,
-	signDescriptor *SignDescriptor,
-	preimage []byte, heightHint uint32) HtlcSucceedInput {
+	signDescriptor *SignDescriptor, preimage []byte, heightHint,
+	blocksToMaturity uint32) HtlcSucceedInput {
 
 	return HtlcSucceedInput{
 		inputKit: inputKit{
-			outpoint:    *outpoint,
-			witnessType: HtlcAcceptedRemoteSuccess,
-			signDesc:    *signDescriptor,
-			heightHint:  heightHint,
+			outpoint:        *outpoint,
+			witnessType:     HtlcAcceptedRemoteSuccess,
+			signDesc:        *signDescriptor,
+			heightHint:      heightHint,
+			blockToMaturity: blocksToMaturity,
 		},
 		preimage: preimage,
 	}
diff --git a/lnwallet/channel.go b/lnwallet/channel.go
index dbb2000a..a348254d 100644
--- a/lnwallet/channel.go
+++ b/lnwallet/channel.go
@@ -5253,7 +5253,8 @@ type IncomingHtlcResolution struct {
 	// pass after the SignedSuccessTx is confirmed in the chain before the
 	// output can be swept.
 	//
-	// NOTE: If SignedSuccessTx is nil, then this field isn't needed.
+	// NOTE: If SignedTimeoutTx is nil, then this field denotes the CSV
+	// delay needed to spend from the commitment transaction.
 	CsvDelay uint32
 
 	// ClaimOutpoint is the final outpoint that needs to be spent in order
@@ -5293,7 +5294,8 @@ type OutgoingHtlcResolution struct {
 	// pass after the SignedTimeoutTx is confirmed in the chain before the
 	// output can be swept.
 	//
-	// NOTE: If SignedTimeoutTx is nil, then this field isn't needed.
+	// NOTE: If SignedTimeoutTx is nil, then this field denotes the CSV
+	// delay needed to spend from the commitment transaction.
 	CsvDelay uint32
 
 	// ClaimOutpoint is the final outpoint that needs to be spent in order
@@ -5366,6 +5368,7 @@ func newOutgoingHtlcResolution(signer input.Signer,
 				},
 				HashType: txscript.SigHashAll,
 			},
+			CsvDelay: HtlcSecondLevelInputSequence(chanType),
 		}, nil
 	}
 
@@ -5487,7 +5490,6 @@ func newIncomingHtlcResolution(signer input.Signer,
 		// SignDescriptor needed to sweep the output.
 		return &IncomingHtlcResolution{
 			ClaimOutpoint: op,
-			CsvDelay:      csvDelay,
 			SweepSignDesc: input.SignDescriptor{
 				KeyDesc:       localChanCfg.HtlcBasePoint,
 				SingleTweak:   keyRing.LocalHtlcKeyTweak,
@@ -5498,6 +5500,7 @@ func newIncomingHtlcResolution(signer input.Signer,
 				},
 				HashType: txscript.SigHashAll,
 			},
+			CsvDelay: HtlcSecondLevelInputSequence(chanType),
 		}, nil
 	}
 
diff --git a/utxonursery.go b/utxonursery.go
index d05a04ed..abff3547 100644
--- a/utxonursery.go
+++ b/utxonursery.go
@@ -397,10 +397,11 @@ func (u *utxoNursery) IncubateOutputs(chanPoint wire.OutPoint,
 
 		// Otherwise, this is actually a kid output as we can sweep it
 		// once the commitment transaction confirms, and the absolute
-		// CLTV lock has expired. We set the CSV delay to zero to
-		// indicate this is actually a CLTV output.
+		// CLTV lock has expired. We set the CSV delay what the
+		// resolution encodes, since the sequence number must be set
+		// accordingly.
 		htlcOutput := makeKidOutput(
-			&htlcRes.ClaimOutpoint, &chanPoint, 0,
+			&htlcRes.ClaimOutpoint, &chanPoint, htlcRes.CsvDelay,
 			input.HtlcOfferedRemoteTimeout,
 			&htlcRes.SweepSignDesc, htlcRes.Expiry,
 		)
@@ -1271,7 +1272,8 @@ type kidOutput struct {
 	// output.
 	//
 	// NOTE: This will be set for: commitment outputs, and incoming HTLC's.
-	// Otherwise, this will be zero.
+	// Otherwise, this will be zero. It will also be non-zero for
+	// commitment types which requires confirmed spends.
 	blocksToMaturity uint32
 
 	// absoluteMaturity is the absolute height that this output will be
diff --git a/utxonursery_test.go b/utxonursery_test.go
index 579bddcf..cbc91269 100644
--- a/utxonursery_test.go
+++ b/utxonursery_test.go
@@ -603,7 +603,6 @@ func createOutgoingRes(onLocalCommitment bool) *lnwallet.OutgoingHtlcResolution
 				Value: 10000,
 			},
 		},
-		CsvDelay: 2,
 	}
 
 	if onLocalCommitment {
@@ -620,8 +619,10 @@ func createOutgoingRes(onLocalCommitment bool) *lnwallet.OutgoingHtlcResolution
 		}
 
 		outgoingRes.SignedTimeoutTx = timeoutTx
+		outgoingRes.CsvDelay = 2
 	} else {
 		outgoingRes.ClaimOutpoint = htlcOp
+		outgoingRes.CsvDelay = 0
 	}
 
 	return &outgoingRes