From 7946d0a25645f80883b264a5a2a0ab595c3b3b7f Mon Sep 17 00:00:00 2001
From: Wilmer Paulino <wilmer.paulino@gmail.com>
Date: Wed, 20 Feb 2019 15:06:57 -0800
Subject: [PATCH] multi: remove ErrDoubleSpend check for PublishTransaction

In this commit, we address a lingering issue within some subsystems that
are responsible for broadcasting transactions. Previously,
ErrDoubleSpend indicated that a transaction was already included in the
mempool/chain. This error was then modified to actually be returned for
conflicting transactions, but its callers were not modified accordingly.
This would lead to conflicting transactions to be interpreted as valid,
when they shouldn't be.
---
 contractcourt/htlc_success_resolver.go | 5 ++---
 fundingmanager.go                      | 2 +-
 utxonursery.go                         | 2 +-
 watchtower/lookout/punisher.go         | 3 +--
 4 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/contractcourt/htlc_success_resolver.go b/contractcourt/htlc_success_resolver.go
index 82fbdc02..abad34b4 100644
--- a/contractcourt/htlc_success_resolver.go
+++ b/contractcourt/htlc_success_resolver.go
@@ -7,7 +7,6 @@ import (
 
 	"github.com/btcsuite/btcd/wire"
 	"github.com/davecgh/go-spew/spew"
-
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/lntypes"
@@ -148,7 +147,7 @@ func (h *htlcSuccessResolver) Resolve() (ContractResolver, error) {
 		// constructed, we'll broadcast the sweep transaction to the
 		// network.
 		err := h.PublishTx(h.sweepTx)
-		if err != nil && err != lnwallet.ErrDoubleSpend {
+		if err != nil {
 			log.Infof("%T(%x): unable to publish tx: %v",
 				h, h.payHash[:], err)
 			return nil, err
@@ -200,7 +199,7 @@ func (h *htlcSuccessResolver) Resolve() (ContractResolver, error) {
 	//
 	// TODO(roasbeef): after changing sighashes send to tx bundler
 	err := h.PublishTx(h.htlcResolution.SignedSuccessTx)
-	if err != nil && err != lnwallet.ErrDoubleSpend {
+	if err != nil {
 		return nil, err
 	}
 
diff --git a/fundingmanager.go b/fundingmanager.go
index a86b1747..49b560a5 100644
--- a/fundingmanager.go
+++ b/fundingmanager.go
@@ -508,7 +508,7 @@ func (f *fundingManager) Start() error {
 			channel.IsInitiator {
 
 			err := f.cfg.PublishTransaction(channel.FundingTxn)
-			if err != nil && err != lnwallet.ErrDoubleSpend {
+			if err != nil {
 				fndgLog.Errorf("Unable to rebroadcast funding "+
 					"tx for ChannelPoint(%v): %v",
 					channel.FundingOutpoint, err)
diff --git a/utxonursery.go b/utxonursery.go
index 36b97815..829d4ba0 100644
--- a/utxonursery.go
+++ b/utxonursery.go
@@ -894,7 +894,7 @@ func (u *utxoNursery) sweepCribOutput(classHeight uint32, baby *babyOutput) erro
 	// We'll now broadcast the HTLC transaction, then wait for it to be
 	// confirmed before transitioning it to kindergarten.
 	err := u.cfg.PublishTransaction(baby.timeoutTx)
-	if err != nil && err != lnwallet.ErrDoubleSpend {
+	if err != nil {
 		utxnLog.Errorf("Unable to broadcast baby tx: "+
 			"%v, %v", err, spew.Sdump(baby.timeoutTx))
 		return err
diff --git a/watchtower/lookout/punisher.go b/watchtower/lookout/punisher.go
index fb441430..eb9c058c 100644
--- a/watchtower/lookout/punisher.go
+++ b/watchtower/lookout/punisher.go
@@ -2,7 +2,6 @@ package lookout
 
 import (
 	"github.com/btcsuite/btcd/wire"
-	"github.com/lightningnetwork/lnd/lnwallet"
 )
 
 // PunisherConfig houses the resources required by the Punisher.
@@ -44,7 +43,7 @@ func (p *BreachPunisher) Punish(desc *JusticeDescriptor, quit <-chan struct{}) e
 		desc.SessionInfo.ID, justiceTxn.TxHash())
 
 	err = p.cfg.PublishTx(justiceTxn)
-	if err != nil && err != lnwallet.ErrDoubleSpend {
+	if err != nil {
 		log.Errorf("Unable to publish justice txn for client=%s"+
 			"with breach-txid=%s: %v",
 			desc.SessionInfo.ID, desc.BreachedCommitTx.TxHash(), err)