chancloser: add nil-tx guard to legacy close test
What the developer wrote
Authored by Jared Tobin
chancloser: add nil-tx guard to legacy close test
Add call tracking to the legacy mockChannel so that every
MarkCoopBroadcasted invocation is recorded. TestTaprootFastClose
now asserts that at least one call was made and that every call
carried a non-nil tx, guarding against the limbo state described
in https://github.com/lightninglabs/taproot-assets/issues/2108.
What changed, and why it matters
This commit only changes a test file. It adds a safety check to make sure a function called during cooperative channel closes is always given a real transaction, not a blank one. The test now records every call and fails if any call has a nil transaction. It does not change the actual production code that users run, so it cannot by itself fix or introduce a live bug.
Treat this as a test-hardening commit. If the referenced limbo state is a real production concern, review the chancloser production code that calls MarkCoopBroadcasted to ensure it never passes a nil transaction, and consider adding a runtime guard or explicit error return there. No urgent deployment action is needed for this test-only change.
Security signals we found
Test-only regression guard for nil transaction in cooperative close path
References external issue about a 'limbo state' when ChanStatusCoopBroadcasted is set without a stored transaction
No production code change; no patch to the actual MarkCoopBroadcasted caller or channel state machine
Evidence from the diff
The change is in lnwallet/chancloser/chancloser_test.go. The legacy mockChannel now tracks each MarkCoopBroadcasted invocation in coopBroadcastTxns. TestTaprootFastClose asserts that both alice and bob made at least one MarkCoopBroadcasted call and that none of those calls passed a nil *wire.MsgTx. The commit message links this to a ‘limbo state’ in a taproot-assets issue, but the patch is purely a regression test guard; no implementation logic is modified.
Changed components
lnwallet/chancloser/chancloser_test.golegacy mockChannel test helperTestTaprootFastCloseInspect captured patch +25 / −2
diff --git a/lnwallet/chancloser/chancloser_test.go b/lnwallet/chancloser/chancloser_test.go
index 5d96b96..16afb65 100644
--- a/lnwallet/chancloser/chancloser_test.go
+++ b/lnwallet/chancloser/chancloser_test.go
@@ -147,6 +147,8 @@ type mockChannel struct {
chanType channeldb.ChannelType
localKey keychain.KeyDescriptor
remoteKey keychain.KeyDescriptor
+
+ coopBroadcastTxns []*wire.MsgTx
}
func (m *mockChannel) ChannelPoint() wire.OutPoint {
@@ -161,8 +163,10 @@ func (m *mockChannel) FundingBlob() fn.Option[tlv.Blob] {
return fn.None[tlv.Blob]()
}
-func (m *mockChannel) MarkCoopBroadcasted(*wire.MsgTx,
- lntypes.ChannelParty) error {
+func (m *mockChannel) MarkCoopBroadcasted(tx *wire.MsgTx,
+ _ lntypes.ChannelParty) error {
+
+ m.coopBroadcastTxns = append(m.coopBroadcastTxns, tx)
return nil
}
@@ -643,4 +647,23 @@ func TestTaprootFastClose(t *testing.T) {
tx, _ = bobCloser.ClosingTx()
require.NotNil(t, tx)
require.True(t, oClosingSigned.IsNone())
+
+ // Every MarkCoopBroadcasted call must have a real close tx.
+ // A nil tx would set ChanStatusCoopBroadcasted without a
+ // stored transaction, creating the limbo state described in
+ // https://github.com/lightninglabs/taproot-assets/issues/2108.
+ require.NotEmpty(t, aliceChan.coopBroadcastTxns,
+ "expected at least one MarkCoopBroadcasted call "+
+ "from alice")
+ require.NotEmpty(t, bobChan.coopBroadcastTxns,
+ "expected at least one MarkCoopBroadcasted call "+
+ "from bob")
+ for i, broadcastTx := range aliceChan.coopBroadcastTxns {
+ require.NotNilf(t, broadcastTx,
+ "alice MarkCoopBroadcasted call %d had nil tx", i)
+ }
+ for i, broadcastTx := range bobChan.coopBroadcastTxns {
+ require.NotNilf(t, broadcastTx,
+ "bob MarkCoopBroadcasted call %d had nil tx", i)
+ }
}
Why this scored 22/100
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