Chrome Release → Validated Backport PR

2. Prepare a synced worktree

Reuse bp-<NN> from e show configs if present, else e worktree add bp-<NN> ~/src/electron-bp-<NN> --source <current> --no-sync.

cd <root>/src/electron
git fetch origin <branch>
git checkout -B security-backport/<branch>/<short-date> origin/<branch>
e use bp-<NN>
e sync 2>&1 | tee /tmp/bp_sync.log

If sync fails with NotADirectoryError: '<root>/src/.git/objects/info/alternates', remove GIT_CACHE_PATH from the bp config's env and retry.

3. Verify IN-TREE vs NEEDS-BACKPORT

For each bug, three checks against the synced repo:

1. git -C "$repo" log HEAD --since='1 year ago' -E --grep="\b${bug}\b" --format='%h %s'
2. Fetch Change-Id from Gerrit, then git log HEAD --grep="^Change-Id: ${cid}$"
3. grep -rlE "(\b${bug}\b|${cid})" <root>/src/electron/patches/

Any hit ⇒ IN-TREE. All empty ⇒ NEEDS-BACKPORT.

For each NEEDS-BACKPORT CL, also fetch its file list (/changes/<proj>~<cl>/revisions/current/files) and skip if every file is under chrome/browser/, chrome/android/, ios/, or components/**/android/ — Electron doesn't compile those.

Report the table now (CVE | Sev | Bug | Component | Verdict | CL) and the proposed backport set; get user sign-off before continuing.

4. Write patches locally (no push yet)

For each backport CL, fetch the raw patch and write it into patches/<dir>/:

curl -s "https://${host}.googlesource.com/changes/${proj//\//%2F}~${cl}/revisions/current/patch" \
  | base64 -d > "patches/${dir}/cherry-pick-${short}.patch"
echo "cherry-pick-${short}.patch" >> "patches/${dir}/.patches"

For repos with no Gerrit host e cherry-pick supports (e.g. libaom on aomedia), instead git cherry-pick the upstream commits onto the synced sub-repo HEAD and git format-patch the result.

For any newly-created patches/<dir>/, append to patches/config.json preserving the compact one-line-per-entry style:

  { "patch_dir": "src/electron/patches/<dir>", "repo": "src/third_party/<dir-or-nested-path>" }

5. Validate with e sync --3

e sync --3 2>&1 | tee /tmp/bp_sync3.log

On Patch failed at NNNN <subject>:

• cd into the failing repo, inspect git diff for conflict markers.
• Test-only files (e.g. web_tests/VirtualTestSuites, *_unittest.cc context drift): take ours (git checkout --ours -- <file>) if the security-relevant hunks merged cleanly.
• Substantive code conflicts: check whether a target-milestone merge CL exists and swap to it. If none exists upstream and the surrounding code is structurally different, drop the patch (delete the file, remove from .patches and config.json) and note it for a separate manual-port PR — do not improvise security-fix semantics.
• After resolving: git add <files> && git -c commit.gpgsign=false am --continue, then e patches <repo> to export the resolved patch, then re-run e sync --3. Repeat until clean.

6. Export → lint → re-apply loop

e patches all
node script/lint.js --patches   # must exit 0

If lint reports findings (typically trailing whitespace on + content lines), fixing them changes the bytes the patch writes, which invalidates the index <old>..<new> blob hashes that e patches baked in. Hand-editing a .patch and pushing it as-is will pass lint locally but fail CI's Apply Patches re-export check with a one-line index hash diff.

So whenever lint (or you) modifies any .patch file after export, round-trip once more:

# fix the lint findings in patches/**/*.patch, then:
e sync            # re-apply the edited patches (no --3 needed; they applied cleanly last time)
e patches all     # re-export so index blob hashes match the edited content
node script/lint.js --patches      # must now exit 0
git diff --quiet -- patches/ || { echo "patches changed again — repeat the loop"; }

Repeat until lint --patches exits 0 and git diff -- patches/ is empty after the final e patches all. Only then is the patch set CI-stable.

7. Commit, push, PR

git add patches/
git commit -m "chore: cherry-pick <N> changes from <dirs>"
git push origin HEAD
gh pr create --repo electron/electron --base <branch> --head <this-branch> \
  --title "chore: cherry-pick <N> changes from <dirs>" \
  --label "<branch>" --label backport-check-skip --label semver/patch --label "security 🔒" \
  --body-file /tmp/pr_body.md

PR body format:

Backports the following changes:

* [`<shortCommit>`](<gerrit-CL-url>) from <patchDir> — <subject> ([<bug>](https://crbug.com/<bug>), CVE-YYYY-NNNN)
* ...

Notes: Security: backported fixes for CVE-YYYY-NNNN, CVE-YYYY-NNNN, ....

Short commit links to the Gerrit CL; bug links to crbug.com; CVE comes from the blog mapping (the patch's own Bug: footer may differ); Notes: is the last line. Mention any dropped patches (with reason) above the Notes: line.

Restore e use <previous> when done.