push-to-forked-pr

push-to-forked-pr

The whole point of this skill: origin is usually the upstream, but the PR's head is on someone else's fork. Pushing to origin updates the upstream's branch, not the PR. You have to push to the fork.

GitHub allows this in two situations:

1. You are the fork owner — straightforward, you own that branch.
2. You are an upstream maintainer and the PR has maintainerCanModify: true (the "Allow edits from maintainers" checkbox the PR author leaves on by default). GitHub then lets the upstream's auth push to the fork branch.

If neither holds, abort and tell the user only the fork owner can push.

---

Procedure

1. Read the PR's head metadata

PR_NUMBER=<N>
gh pr view "$PR_NUMBER" --json state,headRefName,headRefOid,headRepository,headRepositoryOwner,maintainerCanModify,url

Capture:

• state — bail if not "OPEN".
• headRepository.nameWithOwner → the fork (e.g. someone/Repo).
• headRepositoryOwner.login → the fork owner.
• headRefName → the branch on the fork (usually matches local).
• headRefOid → the PR's current head SHA. Your local HEAD must be a descendant.
• maintainerCanModify → must be true if you are not the fork owner.

If headRepository.nameWithOwner matches the upstream's nameWithOwner, this PR is internal:

HEAD_BRANCH=$(gh pr view "$PR_NUMBER" --json headRefName --jq .headRefName)
HEAD_REF_OID=$(gh pr view "$PR_NUMBER" --json headRefOid --jq .headRefOid)
git merge-base --is-ancestor "$HEAD_REF_OID" HEAD && echo ok || echo NOT-DESCENDANT   # abort if NOT-DESCENDANT
git push origin "HEAD:${HEAD_BRANCH}"

Exit the skill once this push lands — do not continue to the fork-push steps below.

2. Confirm you can actually push

gh auth status                        # who am I?
git remote get-url origin             # fetch URL — confirm origin is the UPSTREAM, not the fork
git remote get-url --push origin      # push URL — can differ from the fetch URL if `pushurl` is configured