fuzz: skip broken splicing paths and handle broadcast channel updates by joostjager · Pull Request #4561 · lightningdevkit/rust-lightning

joostjager · 2026-04-14T06:53:58Z

This PR tightens chanmon_consistency so it stays focused on failures we can currently act on.

Splicing fuzzing has been broken for quite a while, and leaving splice opcodes active in the default configuration makes it harder to spot unrelated regressions because runs terminate in known-bad splicing paths instead of continuing toward other failures. This change makes those opcodes bail out unless the target is built with cfg(splicing) enabled, while still keeping the opcode slots in place for dedicated splicing fuzzing later.

This PR also corrects a message-passing issue in chanmon_consistency introduced by #4508. After broadcast channel announcements started flowing through the broadcast queue, the fuzz target was no longer handling that path correctly, which meant it could trip over a known routing mismatch instead of exercising the rest of the state machine.

ldk-reviews-bot · 2026-04-14T06:54:02Z

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

codecov · 2026-04-14T08:04:19Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.98%. Comparing base (78df66d) to head (9f59b33).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #4561 +/- ##
==========================================
- Coverage 86.99% 86.98% -0.02% 
==========================================
Files 163 163 Lines 108744 108744 Branches 108744 108744 ==========================================
- Hits 94605 94589 -16 - Misses 11658 11672 +14 - Partials 2481 2483 +2

Flag	Coverage Δ
fuzzing	`38.09% <ø> (-2.20%)`	⬇️
tests	`86.09% <ø> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

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ldk-claude-review-bot · 2026-04-14T08:08:04Z

The PR is clean. After thorough review:

test_return!() is the normal termination path for the fuzz loop (also used in get_slice! when input is exhausted), so calling it from the splice opcode gates doesn't introduce false panics.
BroadcastChannelUpdate handling is correctly added in all three places that needed it (push_excess_b_events, both branches of drain_msg_events_on_disconnect), and it was already handled in process_msg_events.
The #[allow(unused_variables)] annotations are correct since loggers and fee_estimators are only used inside the now-gated splice arms.
All 8 splice opcodes (0xa0-0xa7) are consistently gated.

No issues found.

The regression was introduced in d627ce1. That change switched fee update opcodes in chanmon_consistency from maybe_update_chan_fees() to timer_tick_occurred(), which can enqueue BroadcastChannelUpdate events while peers are disconnected. The harness already tolerated those events in one delivery path, but still treated them as unreachable in push_excess_b_events and disconnect draining. Accept BroadcastChannelUpdate in those match arms so the fuzz target no longer panics on valid timer tick driven message queues. AI tools were used in preparing this commit.

Keep the splice opcodes in chanmon_consistency available only when the crate is built with cfg(splicing). When splicing is disabled, return early from those opcode handlers instead of calling splice helpers that are not compiled in. Add cfg(splicing) to fuzz/Cargo.toml check-cfg so the guarded code builds cleanly in the fuzz crate. AI tools were used in preparing this commit.

joostjager · 2026-04-14T06:53:58Z

This PR tightens chanmon_consistency so it stays focused on failures we can currently act on.

Splicing fuzzing has been broken for quite a while, and leaving splice opcodes active in the default configuration makes it harder to spot unrelated regressions because runs terminate in known-bad splicing paths instead of continuing toward other failures. This change makes those opcodes bail out unless the target is built with cfg(splicing) enabled, while still keeping the opcode slots in place for dedicated splicing fuzzing later.

This PR also corrects a message-passing issue in chanmon_consistency introduced by #4508. After broadcast channel announcements started flowing through the broadcast queue, the fuzz target was no longer handling that path correctly, which meant it could trip over a known routing mismatch instead of exercising the rest of the state machine.

ldk-reviews-bot · 2026-04-14T06:54:02Z

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

codecov · 2026-04-14T08:04:19Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.98%. Comparing base (78df66d) to head (9f59b33).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #4561 +/- ##
==========================================
- Coverage 86.99% 86.98% -0.02% 
==========================================
Files 163 163 Lines 108744 108744 Branches 108744 108744 ==========================================
- Hits 94605 94589 -16 - Misses 11658 11672 +14 - Partials 2481 2483 +2

Flag	Coverage Δ
fuzzing	`38.09% <ø> (-2.20%)`	⬇️
tests	`86.09% <ø> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

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ldk-claude-review-bot · 2026-04-14T08:08:04Z

The PR is clean. After thorough review:

test_return!() is the normal termination path for the fuzz loop (also used in get_slice! when input is exhausted), so calling it from the splice opcode gates doesn't introduce false panics.
BroadcastChannelUpdate handling is correctly added in all three places that needed it (push_excess_b_events, both branches of drain_msg_events_on_disconnect), and it was already handled in process_msg_events.
The #[allow(unused_variables)] annotations are correct since loggers and fee_estimators are only used inside the now-gated splice arms.
All 8 splice opcodes (0xa0-0xa7) are consistently gated.

No issues found.

The regression was introduced in d627ce1. That change switched fee update opcodes in chanmon_consistency from maybe_update_chan_fees() to timer_tick_occurred(), which can enqueue BroadcastChannelUpdate events while peers are disconnected. The harness already tolerated those events in one delivery path, but still treated them as unreachable in push_excess_b_events and disconnect draining. Accept BroadcastChannelUpdate in those match arms so the fuzz target no longer panics on valid timer tick driven message queues. AI tools were used in preparing this commit.

Keep the splice opcodes in chanmon_consistency available only when the crate is built with cfg(splicing). When splicing is disabled, return early from those opcode handlers instead of calling splice helpers that are not compiled in. Add cfg(splicing) to fuzz/Cargo.toml check-cfg so the guarded code builds cleanly in the fuzz crate. AI tools were used in preparing this commit.

joostjager · 2026-04-14T06:53:58Z

This PR tightens chanmon_consistency so it stays focused on failures we can currently act on.

Splicing fuzzing has been broken for quite a while, and leaving splice opcodes active in the default configuration makes it harder to spot unrelated regressions because runs terminate in known-bad splicing paths instead of continuing toward other failures. This change makes those opcodes bail out unless the target is built with cfg(splicing) enabled, while still keeping the opcode slots in place for dedicated splicing fuzzing later.

This PR also corrects a message-passing issue in chanmon_consistency introduced by #4508. After broadcast channel announcements started flowing through the broadcast queue, the fuzz target was no longer handling that path correctly, which meant it could trip over a known routing mismatch instead of exercising the rest of the state machine.

ldk-reviews-bot · 2026-04-14T06:54:02Z

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

codecov · 2026-04-14T08:04:19Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.98%. Comparing base (78df66d) to head (9f59b33).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #4561 +/- ##
==========================================
- Coverage 86.99% 86.98% -0.02% 
==========================================
Files 163 163 Lines 108744 108744 Branches 108744 108744 ==========================================
- Hits 94605 94589 -16 - Misses 11658 11672 +14 - Partials 2481 2483 +2

Flag	Coverage Δ
fuzzing	`38.09% <ø> (-2.20%)`	⬇️
tests	`86.09% <ø> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

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ldk-claude-review-bot · 2026-04-14T08:08:04Z

The PR is clean. After thorough review:

test_return!() is the normal termination path for the fuzz loop (also used in get_slice! when input is exhausted), so calling it from the splice opcode gates doesn't introduce false panics.
BroadcastChannelUpdate handling is correctly added in all three places that needed it (push_excess_b_events, both branches of drain_msg_events_on_disconnect), and it was already handled in process_msg_events.
The #[allow(unused_variables)] annotations are correct since loggers and fee_estimators are only used inside the now-gated splice arms.
All 8 splice opcodes (0xa0-0xa7) are consistently gated.

No issues found.

The regression was introduced in d627ce1. That change switched fee update opcodes in chanmon_consistency from maybe_update_chan_fees() to timer_tick_occurred(), which can enqueue BroadcastChannelUpdate events while peers are disconnected. The harness already tolerated those events in one delivery path, but still treated them as unreachable in push_excess_b_events and disconnect draining. Accept BroadcastChannelUpdate in those match arms so the fuzz target no longer panics on valid timer tick driven message queues. AI tools were used in preparing this commit.

Keep the splice opcodes in chanmon_consistency available only when the crate is built with cfg(splicing). When splicing is disabled, return early from those opcode handlers instead of calling splice helpers that are not compiled in. Add cfg(splicing) to fuzz/Cargo.toml check-cfg so the guarded code builds cleanly in the fuzz crate. AI tools were used in preparing this commit.

joostjager · 2026-04-14T06:53:58Z

This PR tightens chanmon_consistency so it stays focused on failures we can currently act on.

Splicing fuzzing has been broken for quite a while, and leaving splice opcodes active in the default configuration makes it harder to spot unrelated regressions because runs terminate in known-bad splicing paths instead of continuing toward other failures. This change makes those opcodes bail out unless the target is built with cfg(splicing) enabled, while still keeping the opcode slots in place for dedicated splicing fuzzing later.

This PR also corrects a message-passing issue in chanmon_consistency introduced by #4508. After broadcast channel announcements started flowing through the broadcast queue, the fuzz target was no longer handling that path correctly, which meant it could trip over a known routing mismatch instead of exercising the rest of the state machine.

ldk-reviews-bot · 2026-04-14T06:54:02Z

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

codecov · 2026-04-14T08:04:19Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.98%. Comparing base (78df66d) to head (9f59b33).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #4561 +/- ##
==========================================
- Coverage 86.99% 86.98% -0.02% 
==========================================
Files 163 163 Lines 108744 108744 Branches 108744 108744 ==========================================
- Hits 94605 94589 -16 - Misses 11658 11672 +14 - Partials 2481 2483 +2

Flag	Coverage Δ
fuzzing	`38.09% <ø> (-2.20%)`	⬇️
tests	`86.09% <ø> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
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❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

ldk-claude-review-bot · 2026-04-14T08:08:04Z

The PR is clean. After thorough review:

test_return!() is the normal termination path for the fuzz loop (also used in get_slice! when input is exhausted), so calling it from the splice opcode gates doesn't introduce false panics.
BroadcastChannelUpdate handling is correctly added in all three places that needed it (push_excess_b_events, both branches of drain_msg_events_on_disconnect), and it was already handled in process_msg_events.
The #[allow(unused_variables)] annotations are correct since loggers and fee_estimators are only used inside the now-gated splice arms.
All 8 splice opcodes (0xa0-0xa7) are consistently gated.

No issues found.

The regression was introduced in d627ce1. That change switched fee update opcodes in chanmon_consistency from maybe_update_chan_fees() to timer_tick_occurred(), which can enqueue BroadcastChannelUpdate events while peers are disconnected. The harness already tolerated those events in one delivery path, but still treated them as unreachable in push_excess_b_events and disconnect draining. Accept BroadcastChannelUpdate in those match arms so the fuzz target no longer panics on valid timer tick driven message queues. AI tools were used in preparing this commit.

Keep the splice opcodes in chanmon_consistency available only when the crate is built with cfg(splicing). When splicing is disabled, return early from those opcode handlers instead of calling splice helpers that are not compiled in. Add cfg(splicing) to fuzz/Cargo.toml check-cfg so the guarded code builds cleanly in the fuzz crate. AI tools were used in preparing this commit.

joostjager · 2026-04-14T06:53:58Z

This PR tightens chanmon_consistency so it stays focused on failures we can currently act on.

Splicing fuzzing has been broken for quite a while, and leaving splice opcodes active in the default configuration makes it harder to spot unrelated regressions because runs terminate in known-bad splicing paths instead of continuing toward other failures. This change makes those opcodes bail out unless the target is built with cfg(splicing) enabled, while still keeping the opcode slots in place for dedicated splicing fuzzing later.

This PR also corrects a message-passing issue in chanmon_consistency introduced by #4508. After broadcast channel announcements started flowing through the broadcast queue, the fuzz target was no longer handling that path correctly, which meant it could trip over a known routing mismatch instead of exercising the rest of the state machine.

ldk-reviews-bot · 2026-04-14T06:54:02Z

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

codecov · 2026-04-14T08:04:19Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.98%. Comparing base (78df66d) to head (9f59b33).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #4561 +/- ##
==========================================
- Coverage 86.99% 86.98% -0.02% 
==========================================
Files 163 163 Lines 108744 108744 Branches 108744 108744 ==========================================
- Hits 94605 94589 -16 - Misses 11658 11672 +14 - Partials 2481 2483 +2

Flag	Coverage Δ
fuzzing	`38.09% <ø> (-2.20%)`	⬇️
tests	`86.09% <ø> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

ldk-claude-review-bot · 2026-04-14T08:08:04Z

The PR is clean. After thorough review:

test_return!() is the normal termination path for the fuzz loop (also used in get_slice! when input is exhausted), so calling it from the splice opcode gates doesn't introduce false panics.
BroadcastChannelUpdate handling is correctly added in all three places that needed it (push_excess_b_events, both branches of drain_msg_events_on_disconnect), and it was already handled in process_msg_events.
The #[allow(unused_variables)] annotations are correct since loggers and fee_estimators are only used inside the now-gated splice arms.
All 8 splice opcodes (0xa0-0xa7) are consistently gated.

No issues found.

The regression was introduced in d627ce1. That change switched fee update opcodes in chanmon_consistency from maybe_update_chan_fees() to timer_tick_occurred(), which can enqueue BroadcastChannelUpdate events while peers are disconnected. The harness already tolerated those events in one delivery path, but still treated them as unreachable in push_excess_b_events and disconnect draining. Accept BroadcastChannelUpdate in those match arms so the fuzz target no longer panics on valid timer tick driven message queues. AI tools were used in preparing this commit.

Keep the splice opcodes in chanmon_consistency available only when the crate is built with cfg(splicing). When splicing is disabled, return early from those opcode handlers instead of calling splice helpers that are not compiled in. Add cfg(splicing) to fuzz/Cargo.toml check-cfg so the guarded code builds cleanly in the fuzz crate. AI tools were used in preparing this commit.

joostjager · 2026-04-14T06:53:58Z

This PR tightens chanmon_consistency so it stays focused on failures we can currently act on.

Splicing fuzzing has been broken for quite a while, and leaving splice opcodes active in the default configuration makes it harder to spot unrelated regressions because runs terminate in known-bad splicing paths instead of continuing toward other failures. This change makes those opcodes bail out unless the target is built with cfg(splicing) enabled, while still keeping the opcode slots in place for dedicated splicing fuzzing later.

This PR also corrects a message-passing issue in chanmon_consistency introduced by #4508. After broadcast channel announcements started flowing through the broadcast queue, the fuzz target was no longer handling that path correctly, which meant it could trip over a known routing mismatch instead of exercising the rest of the state machine.

ldk-reviews-bot · 2026-04-14T06:54:02Z

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

codecov · 2026-04-14T08:04:19Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.98%. Comparing base (78df66d) to head (9f59b33).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #4561 +/- ##
==========================================
- Coverage 86.99% 86.98% -0.02% 
==========================================
Files 163 163 Lines 108744 108744 Branches 108744 108744 ==========================================
- Hits 94605 94589 -16 - Misses 11658 11672 +14 - Partials 2481 2483 +2

Flag	Coverage Δ
fuzzing	`38.09% <ø> (-2.20%)`	⬇️
tests	`86.09% <ø> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

ldk-claude-review-bot · 2026-04-14T08:08:04Z

The PR is clean. After thorough review:

test_return!() is the normal termination path for the fuzz loop (also used in get_slice! when input is exhausted), so calling it from the splice opcode gates doesn't introduce false panics.
BroadcastChannelUpdate handling is correctly added in all three places that needed it (push_excess_b_events, both branches of drain_msg_events_on_disconnect), and it was already handled in process_msg_events.
The #[allow(unused_variables)] annotations are correct since loggers and fee_estimators are only used inside the now-gated splice arms.
All 8 splice opcodes (0xa0-0xa7) are consistently gated.

No issues found.

The regression was introduced in d627ce1. That change switched fee update opcodes in chanmon_consistency from maybe_update_chan_fees() to timer_tick_occurred(), which can enqueue BroadcastChannelUpdate events while peers are disconnected. The harness already tolerated those events in one delivery path, but still treated them as unreachable in push_excess_b_events and disconnect draining. Accept BroadcastChannelUpdate in those match arms so the fuzz target no longer panics on valid timer tick driven message queues. AI tools were used in preparing this commit.

Keep the splice opcodes in chanmon_consistency available only when the crate is built with cfg(splicing). When splicing is disabled, return early from those opcode handlers instead of calling splice helpers that are not compiled in. Add cfg(splicing) to fuzz/Cargo.toml check-cfg so the guarded code builds cleanly in the fuzz crate. AI tools were used in preparing this commit.

joostjager · 2026-04-14T06:53:58Z

This PR tightens chanmon_consistency so it stays focused on failures we can currently act on.

Splicing fuzzing has been broken for quite a while, and leaving splice opcodes active in the default configuration makes it harder to spot unrelated regressions because runs terminate in known-bad splicing paths instead of continuing toward other failures. This change makes those opcodes bail out unless the target is built with cfg(splicing) enabled, while still keeping the opcode slots in place for dedicated splicing fuzzing later.

This PR also corrects a message-passing issue in chanmon_consistency introduced by #4508. After broadcast channel announcements started flowing through the broadcast queue, the fuzz target was no longer handling that path correctly, which meant it could trip over a known routing mismatch instead of exercising the rest of the state machine.

ldk-reviews-bot · 2026-04-14T06:54:02Z

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

codecov · 2026-04-14T08:04:19Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.98%. Comparing base (78df66d) to head (9f59b33).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #4561 +/- ##
==========================================
- Coverage 86.99% 86.98% -0.02% 
==========================================
Files 163 163 Lines 108744 108744 Branches 108744 108744 ==========================================
- Hits 94605 94589 -16 - Misses 11658 11672 +14 - Partials 2481 2483 +2

Flag	Coverage Δ
fuzzing	`38.09% <ø> (-2.20%)`	⬇️
tests	`86.09% <ø> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

ldk-claude-review-bot · 2026-04-14T08:08:04Z

The PR is clean. After thorough review:

test_return!() is the normal termination path for the fuzz loop (also used in get_slice! when input is exhausted), so calling it from the splice opcode gates doesn't introduce false panics.
BroadcastChannelUpdate handling is correctly added in all three places that needed it (push_excess_b_events, both branches of drain_msg_events_on_disconnect), and it was already handled in process_msg_events.
The #[allow(unused_variables)] annotations are correct since loggers and fee_estimators are only used inside the now-gated splice arms.
All 8 splice opcodes (0xa0-0xa7) are consistently gated.

No issues found.

The regression was introduced in d627ce1. That change switched fee update opcodes in chanmon_consistency from maybe_update_chan_fees() to timer_tick_occurred(), which can enqueue BroadcastChannelUpdate events while peers are disconnected. The harness already tolerated those events in one delivery path, but still treated them as unreachable in push_excess_b_events and disconnect draining. Accept BroadcastChannelUpdate in those match arms so the fuzz target no longer panics on valid timer tick driven message queues. AI tools were used in preparing this commit.

Keep the splice opcodes in chanmon_consistency available only when the crate is built with cfg(splicing). When splicing is disabled, return early from those opcode handlers instead of calling splice helpers that are not compiled in. Add cfg(splicing) to fuzz/Cargo.toml check-cfg so the guarded code builds cleanly in the fuzz crate. AI tools were used in preparing this commit.

joostjager · 2026-04-14T06:53:58Z

This PR tightens chanmon_consistency so it stays focused on failures we can currently act on.

Splicing fuzzing has been broken for quite a while, and leaving splice opcodes active in the default configuration makes it harder to spot unrelated regressions because runs terminate in known-bad splicing paths instead of continuing toward other failures. This change makes those opcodes bail out unless the target is built with cfg(splicing) enabled, while still keeping the opcode slots in place for dedicated splicing fuzzing later.

This PR also corrects a message-passing issue in chanmon_consistency introduced by #4508. After broadcast channel announcements started flowing through the broadcast queue, the fuzz target was no longer handling that path correctly, which meant it could trip over a known routing mismatch instead of exercising the rest of the state machine.

ldk-reviews-bot · 2026-04-14T06:54:02Z

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

codecov · 2026-04-14T08:04:19Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.98%. Comparing base (78df66d) to head (9f59b33).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #4561 +/- ##
==========================================
- Coverage 86.99% 86.98% -0.02% 
==========================================
Files 163 163 Lines 108744 108744 Branches 108744 108744 ==========================================
- Hits 94605 94589 -16 - Misses 11658 11672 +14 - Partials 2481 2483 +2

Flag	Coverage Δ
fuzzing	`38.09% <ø> (-2.20%)`	⬇️
tests	`86.09% <ø> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

ldk-claude-review-bot · 2026-04-14T08:08:04Z

The PR is clean. After thorough review:

test_return!() is the normal termination path for the fuzz loop (also used in get_slice! when input is exhausted), so calling it from the splice opcode gates doesn't introduce false panics.
BroadcastChannelUpdate handling is correctly added in all three places that needed it (push_excess_b_events, both branches of drain_msg_events_on_disconnect), and it was already handled in process_msg_events.
The #[allow(unused_variables)] annotations are correct since loggers and fee_estimators are only used inside the now-gated splice arms.
All 8 splice opcodes (0xa0-0xa7) are consistently gated.

No issues found.

The regression was introduced in d627ce1. That change switched fee update opcodes in chanmon_consistency from maybe_update_chan_fees() to timer_tick_occurred(), which can enqueue BroadcastChannelUpdate events while peers are disconnected. The harness already tolerated those events in one delivery path, but still treated them as unreachable in push_excess_b_events and disconnect draining. Accept BroadcastChannelUpdate in those match arms so the fuzz target no longer panics on valid timer tick driven message queues. AI tools were used in preparing this commit.

Keep the splice opcodes in chanmon_consistency available only when the crate is built with cfg(splicing). When splicing is disabled, return early from those opcode handlers instead of calling splice helpers that are not compiled in. Add cfg(splicing) to fuzz/Cargo.toml check-cfg so the guarded code builds cleanly in the fuzz crate. AI tools were used in preparing this commit.

joostjager changed the title ~~Fuzz disable splices~~fuzz: skip broken splicing paths and handle broadcast channel updatesApr 14, 2026

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Split fuzz runners by hash mode #4565
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Fix chanmon_consistency fuzz test for splice RBF #4536
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fuzz: remove the splicing cfg gate from chanmon_consistency #4581
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Fix chanmon_consistency fuzz test for splice RBF #4536
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Fix chanmon_consistency fuzz test for splice RBF #4536
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