fix: a potential deadlock in chain follower fork handling

[hanabi1224]

Summary of changes

During fork handling, is_ready_for_validation could return true for a tipset whose grandparent is validated but parent is not, which potentially causes a deadlock.

This will likely fix #6042 (comment)

Changes introduced in this pull request:

Reference issue to close (if applicable)

Closes

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

Summary by CodeRabbit

• Refactor

  • Internal helper renamed; behavior and user-facing logic unchanged.

• Documentation

  • Changelog updated to include the fix; duplicate entry placement corrected.

• Chores

  • No user-visible changes or new functionality in this release.

[coderabbitai]

Walkthrough

Renamed an internal helper in SyncStateMachine from is_validated to is_parent_validated in src/chain_sync/chain_follower.rs; logic unchanged and all internal call sites updated. Also added a changelog entry for PR 6235 in CHANGELOG.md.

Changes

Cohort / File(s)	Change Summary
SyncStateMachine method rename src/chain_sync/chain_follower.rs	Renamed internal helper is_validated → is_parent_validated; preserved logic (checks stateless_mode or parent_state presence); updated all internal callers.
Changelog updates CHANGELOG.md	Added PR 6235 entry ("Fixed a potential deadlock in chain follower when handling fork(s)") in unreleased and Forest v0.30.2 "Garuda" sections (duplicate entries).

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

• Single, localized rename with consistent caller updates.
• Minor documentation/changelog edits.

Files/areas to spot-check:

• src/chain_sync/chain_follower.rs — ensure no external/public API break and tests/uses updated.
• CHANGELOG.md — verify duplicate entries are intentional.

Suggested reviewers

• elmattic
• LesnyRumcajs

Pre-merge checks and finishing touches

❌ Failed checks (1 warning, 1 inconclusive)

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.
Linked Issues check	❓ Inconclusive	The PR addresses a deadlock in fork handling by renaming is_validated to is_parent_validated, which aligns with fixing the root cause of desynchronization in issue #6042 but does not comprehensively address all stated objectives (future-dated blocks, state-root versions, F3 handling).	Clarify whether this incremental deadlock fix is a complete solution to issue #6042 or a partial fix that requires additional changes to address all identified root causes.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: fixing a potential deadlock in chain follower fork handling, which directly relates to the root cause identified in the PR description.
Out of Scope Changes check	✅ Passed	All changes are focused on the deadlock issue: renaming the internal helper method and updating the CHANGELOG accordingly, with no unrelated modifications detected.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch hm/potential-deadlock-in-fork-handling

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📜 Recent review details

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Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 0e39f2f and 10b0ae1.

📒 Files selected for processing (1)

• CHANGELOG.md (1 hunks)

✅ Files skipped from review due to trivial changes (1)

• CHANGELOG.md

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (8)

• GitHub Check: All lint checks
• GitHub Check: tests
• GitHub Check: tests-release
• GitHub Check: Build Ubuntu
• GitHub Check: cargo-publish-dry-run
• GitHub Check: Build MacOS
• GitHub Check: Build forest binaries on Linux AMD64
• GitHub Check: Check

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[LesnyRumcajs]

changelog?

[hanabi1224]

changelog?

@LesnyRumcajs updated