Merge pull request #9627 from yyforyongyu/sweep-under-budget

Sweep inputs even the budget cannot be covered

Author: yyforyongyu

docs/release-notes/release-notes-0.19.0.md

@@ -162,6 +162,12 @@ close transaction.
   tests to set a lower value for faster funding confirmation timeout while
   keeping the default of 2016 blocks for production stability.
 
+* Previously when sweeping inputs, the sweeper will wait until the specified
+  budget can be covered by the inputs, which could cause the sweep to be
+  delayed, and the sweeping tx ends up using large fees. This is now
+  [changed](https://github.com/lightningnetwork/lnd/pull/9627) so the sweeper
+  will always attempt the sweep as long as the budget can be partially covered.
+
 ## RPC Additions
 
 * [Add a new rpc endpoint](https://github.com/lightningnetwork/lnd/pull/8843)

itest/list_on_test.go

@@ -690,6 +690,10 @@ var allTestCases = []*lntest.TestCase{
 		Name:     "rbf coop close",
 		TestFunc: testCoopCloseRbf,
 	},
+	{
+		Name:     "bump fee low budget",
+		TestFunc: testBumpFeeLowBudget,
+	},
 }
 
 // appendPrefixed is used to add a prefix to each test name in the subtests

itest/lnd_funding_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/txscript"
+	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainreg"
 	"github.com/lightningnetwork/lnd/funding"
 	"github.com/lightningnetwork/lnd/labels"
@@ -466,20 +467,29 @@ func runChannelFundingInputTypes(ht *lntest.HarnessTest, alice,
 		burnAddr = "bcrt1qxsnqpdc842lu8c0xlllgvejt6rhy49u6fmpgyz"
 	)
 
-	fundMixed := func(amt btcutil.Amount, target *node.HarnessNode) {
+	fundMixed := func(amt btcutil.Amount,
+		target *node.HarnessNode) *wire.MsgTx {
+
 		ht.FundCoins(amt/5, target)
 		ht.FundCoins(amt/5, target)
 		ht.FundCoinsP2TR(amt/5, target)
 		ht.FundCoinsP2TR(amt/5, target)
 		ht.FundCoinsP2TR(amt/5, target)
+
+		return nil
 	}
-	fundMultipleP2TR := func(amt btcutil.Amount, target *node.HarnessNode) {
+	fundMultipleP2TR := func(amt btcutil.Amount,
+		target *node.HarnessNode) *wire.MsgTx {
+
 		ht.FundCoinsP2TR(amt/4, target)
 		ht.FundCoinsP2TR(amt/4, target)
 		ht.FundCoinsP2TR(amt/4, target)
 		ht.FundCoinsP2TR(amt/4, target)
+
+		return nil
 	}
-	fundWithTypes := []func(amt btcutil.Amount, target *node.HarnessNode){
+	fundWithTypes := []func(amt btcutil.Amount,
+		target *node.HarnessNode) *wire.MsgTx{
 		ht.FundCoins, ht.FundCoinsNP2WKH, ht.FundCoinsP2TR, fundMixed,
 		fundMultipleP2TR,
 	}

itest/lnd_multi-hop_force_close_test.go

@@ -2570,7 +2570,7 @@ func runLocalPreimageClaimLeased(ht *lntest.HarnessTest,
 	// We'll now mine enough blocks so Carol decides that she needs to go
 	// on-chain to claim the HTLC as Bob has been inactive.
 	numBlocks := padCLTV(
-		invoiceExpiry - ht.CurrentHeight() - incomingBroadcastDelta - 1,
+		invoiceExpiry - ht.CurrentHeight() - incomingBroadcastDelta,
 	)
 	ht.MineBlocks(int(numBlocks))