cherry-pick-resolve-conflict

Cherry-pick Resolve Conflict

Goal

Cherry-pick one commit safely and repeatably in TiKV: check if it is already applied, avoid rerere, resolve conflicts with real subsystem understanding, run the repository’s required checks, and deep-review the effective change only if the pick is applied.

Inputs

• commit_sha: the source commit to cherry-pick

TiKV-Specific Rules

• Require a clean working tree before starting. Do not stash or discard unrelated user changes.
• Never rely on git rerere for conflict resolution.
• Read AGENTS.md and use TiKV’s repository entrypoints from Makefile.
• Treat make format and make clippy as authoritative repository checks, not raw cargo fmt or raw cargo clippy.
• If make clippy fails in scripts/deny, record that separately from Clippy lint results because scripts/clippy-all may not have run yet.
• Prefer targeted test execution when you can identify the affected subsystem. If the touched area is broad or the right target is unclear, escalate to broader test coverage.

Workflow

1. Preconditions

• Require a clean working tree before starting: git status --porcelain must be empty.
• If the tree is dirty, stop and ask the user how they want to proceed. Never discard unrelated changes.

2. Collect commit info

• git show -s --format='%H%n%s' <commit_sha>
• Pick a stable grep_key from the subject line. Prefer PR numbers like #1234, otherwise choose another unique token.

3. Pre-check

• git log --oneline --grep '<grep_key>'
• If the output clearly shows the change is already on the current branch, skip the cherry-pick.

4. Cherry-pick

• git cherry-pick -x <commit_sha>

5. Resolve conflicts if needed

• Inspect conflicts with git status.
• Before editing conflict markers, fully understand what the picked commit changes:
  • Read the full patch: git show <commit_sha>
  • Identify the intended behavior change, invariant, or bug fix
  • Separate core logic changes from mechanical fallout such as imports or signature propagation
• Read the conflicting TiKV code paths in full before editing. Do not resolve by symbol-name guessing.
• For non-trivial or semantic conflicts, identify which prior commit on the current branch caused the divergence:
  • Use git blame -w on HEAD for the relevant ours-side lines
  • Record the responsible commit SHA and subject
  • Compare that commit’s intent with the cherry-picked change and resolve to preserve the correct combined behavior
• For trivial or mechanical conflicts, keep resolution localized and do not spend time on provenance unless behavior is ambiguous.
• After resolving:
  • git add <paths>
  • make format
  • git cherry-pick --continue
• If Git reports an empty patch during or after resolution:
  • git cherry-pick --skip
  • Treat it as skipped (empty patch)

6. Validate if applied

If the result is picked or picked (conflicts resolved), validation is required.

• Always run:
  • cargo check --all
  • make clippy
• Run tests that match the touched subsystem:
  • Prefer env EXTRA_CARGO_ARGS=$TESTNAME make test_with_nextest when you can name a focused test target
  • Use ./scripts/test $TESTNAME -- --nocapture when a specific Rust test name is already known
  • If the change affects shared core paths such as src/storage, src/server, components/raftstore, components/raftstore-v2, components/cdc, or the correct focused target is unclear, run make test
• If any validation fails:
  • investigate the root cause
  • distinguish code regressions from missing prerequisite commits, dependency-security failures, or environment/toolchain blockers
  • do not paper over failures with unrelated edits

7. Deep review only if applied

• Only if the cherry-pick is applied should you perform a deep review of the effective change.
• In this repository, use the local deep-review skill after the pick so the final report covers problem summary, solution mechanics, findings, and TiKV-specific validation gaps.

Output Summary Template

- Result: `picked` / `picked (conflicts resolved)` / `skipped (already applied)` / `skipped (empty patch)` / `blocked (dirty worktree)`
- Pre-check:
  - `git log --oneline --grep "<grep_key>"`: [matched / no match]
- Cherry-pick:
  - Command: `git cherry-pick -x <commit_sha>`
  - Conflicts: [none | list files]
- Conflict analysis (only for non-trivial or semantic conflicts):
  - Ours-side provenance: `<prior_commit_sha>` - <prior_subject> (from `git blame -w`)
  - Intent check: [compatible / conflicting] with rationale
- Resolve notes:
  - [What changed, why, and evidence]
- Validation:
  - `make format`: [pass / fail / blocked / not run]
  - `cargo check --all`: [pass / fail / blocked]
  - Focused tests or `make test`: [pass / fail / not run]
  - `make clippy`: [pass / fail / blocked]
  - `scripts/deny` within `make clippy`: [pass / fail / not reached]
  - `scripts/clippy-all` within `make clippy`: [pass / fail / not reached]