Fix off-by-one in PushBlock that causes nil dereference panic#2924
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wen-coding wants to merge 7 commits intomainfrom
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Fix off-by-one in PushBlock that causes nil dereference panic#2924wen-coding wants to merge 7 commits intomainfrom
wen-coding wants to merge 7 commits intomainfrom
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PushBlock's WaitUntil used n <= inner.nextQC, allowing it to proceed when n == nextQC. Since inner.qcs stores [first, nextQC), the lookup returns nil, causing a panic on qc.Headers(). Changed to n < nextQC to match every other waiter in the file. Added defense-in-depth nil check with a descriptive error message. Co-authored-by: Cursor <cursoragent@cursor.com>
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## main #2924 +/- ##
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- Coverage 57.35% 57.33% -0.02%
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Files 2095 2095
Lines 172870 172870
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- Hits 99142 99110 -32
- Misses 64842 64869 +27
- Partials 8886 8891 +5
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WaitUntil(n < nextQC) guarantees inner.qcs[n] is non-nil, making the defense-in-depth nil check dead code that triggers coverage complaints. Co-authored-by: Cursor <cursoragent@cursor.com>
pompon0
reviewed
Feb 19, 2026
| "github.com/sei-protocol/sei-chain/sei-tendermint/internal/autobahn/types" | ||
| "github.com/sei-protocol/sei-chain/sei-tendermint/libs/utils" | ||
| "github.com/sei-protocol/sei-chain/sei-tendermint/libs/utils/scope" | ||
| "github.com/stretchr/testify/require" |
Contributor
There was a problem hiding this comment.
libs/utils/require. It contains a strongly typed wrappers of testify/require. If you are missing any wrappers, you can add them there.
pompon0
reviewed
Feb 19, 2026
| _, err := state.TryBlock(gr2.First) | ||
| require.ErrorIs(t, err, ErrNotFound) | ||
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| // PushBlock for a block in qc2's range. With the off-by-one bug |
pompon0
reviewed
Feb 19, 2026
| // (n <= inner.nextQC), this would immediately dereference a nil QC | ||
| // pointer and panic. With the fix, it waits for the QC. | ||
| errc := make(chan error, 1) | ||
| go func() { |
Contributor
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this looks like a great use case for https://go.dev/blog/synctest . Do you want to give it a try?
pompon0
approved these changes
Feb 19, 2026
Replace manual goroutine + channel pattern with synctest.Test/Wait, enabling a stronger intermediate assertion that the block is absent while PushBlock is blocked. Also switch to libs/utils/require. Co-authored-by: Cursor <cursoragent@cursor.com>
arajasek
approved these changes
Feb 19, 2026
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Summary
PushBlock: TheWaitUntilcondition usedn <= inner.nextQC, which allowsPushBlockto proceed whenn == nextQC. Sinceinner.qcsstores entries for the half-open range[first, nextQC), the map lookup returnsnil, and the subsequentqc.Headers()call panics with a nil pointer dereference. Changed ton < inner.nextQCto match every other waiter in the file (QC,Block,GlobalBlock,AppProposal).