Sync main after merge

Sync Main After Merge

Use this skill for merge-completion tasks on the default branch.

1. Identify the repo's default branch.
   • Prefer origin/HEAD when it exists.
   • Fall back to main, then master.
2. Check the target checkout for a clean worktree.
   • If uncommitted or untracked changes exist, stop before overwriting anything.
3. Fetch and prune remote refs.
   • git fetch origin --prune
4. If the request includes the merge itself, merge the topic branch or worktree branch into the default branch first.
   • Switch to the default branch first, then merge the branch the user named or the branch currently associated with the worktree.
   • Prefer fast-forward or the repo's documented merge policy.
   • If the default branch is protected, do not push directly; route the merge through a pull request, then continue after the PR lands.
5. Switch to the default branch locally.
   • git switch <default-branch>
   • If git switch fails because the branch is already checked out in another worktree, stop and resolve that worktree instead of forcing a duplicate checkout.
6. Sync the local default branch with remote.
   • Use git pull --ff-only for the normal case.
   • If the user explicitly wants the local branch to match origin/<default-branch> exactly, confirm that dropping any local commits is acceptable and the worktree is clean, then use git reset --hard origin/<default-branch> after fetching.
   • After a protected-branch PR merges, fetch again before pulling so the local branch sees the new remote commit.
7. Verify the result.
   • git status --short --branch
   • Confirm the local branch and origin/<default-branch> point to the expected commit.

Guardrails

• Use git switch, not git checkout.
• Never discard local changes unless the user explicitly asked for an exact remote match.
• Do not assume main; use master only when that is the actual default branch.
• If the target branch is ambiguous, resolve that before changing history.