pmproxy/UBSAN: fix out-of-bounds access

[rmetrich]

Pull Request Description

This is seen in pmproxy.log as:

query.c:240:29: runtime error: index 1 out of bounds for type 'seriesGetSID [*]'

Pull Request Description

Related PR

See also ASAN+UBSAN PR

[coderabbitai]

Important

Review skipped

Review was skipped as selected files did not have any reviewable changes.

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📥 Commits

Reviewing files that changed from the base of the PR and between 7f218c8 and 5d89a9e.

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⚙️ Run configuration

• Configuration used: Repository YAML (base), Repository UI (inherited), Organization UI (inherited)
• Review profile: CHILL
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📥 Commits

Reviewing files that changed from the base of the PR and between f042c2e and 7f218c8.

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📒 Files selected for processing (1)

• src/libpcp_web/src/query.c

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📝 Summary

Summary by CodeRabbit

• No user-facing changes
  • This update changes internal storage only; no end-user behavior is affected.

Walkthrough

The seriesGetLookup.series member changes from a zero-length array to a flexible array member. Existing allocation and lookup logic still use nseries to size and access the trailing entries.

Changes

Series lookup storage

Layer / File(s)	Summary
Flexible array declaration src/libpcp_web/src/query.c	seriesGetLookup.series is now a flexible array member. Allocation and lookup continue to use nseries.

Suggested reviewers: natoscott

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Priority: ⬇️ Low

Change: Bug fix

Merge Risk: ⚪ Minimal · up to 7f218

This is a one-line declaration change that silences a sanitizer out-of-bounds report for series lookups. It does not change allocation or lookup behavior, so it adds no new risk and is ready to merge.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the UBSAN out-of-bounds access fix in pmproxy.
Description check	✅ Passed	The description reports the UBSAN error that this change addresses and links a related PR.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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_{A rabbit checks the trailing array,
One more neat entry tucked away.
The count still guides each lookup right,
The series rest in flexible flight.
Then hops off, pleased with the change.}

_{Comment @coderabbitai help to get the list of available commands.}