Fluentbit crashes when channel does not exists or it is ignored

[ashinde-ai]

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Backporting

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Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

Summary by CodeRabbit

• Bug Fixes
  • Improved stability by adding safety checks to prevent crashes in Windows Event Log collection when no event channels are configured or active.
  • Enhanced shutdown process reliability with additional protective checks.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

Walkthrough

Added null-safety guards to the Windows Event Log input plugin. A check skips collection when active channels are absent in in_winevtlog_collect, and in_winevtlog_exit now null-checks before dereferencing the active channel pointer.

Changes

Cohort / File(s)	Summary
Null-safety hardening plugins/in_winevtlog/in_winevtlog.c	Added null-check guards in in_winevtlog_collect to skip collection when ctx or ctx->active_channel is NULL; wrapped winevtlog_close_all in in_winevtlog_exit with null-check for ctx->active_channel

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

• The changes are localized null-safety checks, which are straightforward to verify
• Two separate defensive guards that follow a consistent pattern
• Minimal impact on control flow or logic

Suggested labels

docs-required

Suggested reviewers

• edsiper
• koleini

Poem

🐰 A rabbit hops through channels bright,
With null-checks guarding left and right!
No derefs without a shield so true,
The logs flow safe—hooray for you! 🌿✨

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title directly describes the main change: fixing a crash when a channel does not exist or is ignored, which matches the guard additions and null-checks in the code.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[cosmo0920]

We only need to guard NULL deref lines.
We shouldn't exit in_winevtlog plugin even if there's no active channels.

[cosmo0920]

We don't want to do this. This is because some sort of usages implies that there is no active channels but still wanted to run without collecting Windows EventLog.