Fixes issue in which a failed backport runs would not cleanup the branch
(issue 1) and then on the next backport attempt, it would bail out early
because it checks if a branch with that name already exists (issue 2).
The workflow now treats existing backport branches as reusable unless an
open PR already references them (issue 2 solution), force-updates any
reused branch with the latest cherry-pick, and records them so a new
cleanup step can delete the branch if the run fails (issue 1 solution).
That prevents stranded refs from blocking future backport runs while
keeping active backport PRs intact.
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6620-ci-fix-backport-workflow-not-cleaning-up-branch-on-failure-and-not-able-to-update-existi-2a36d73d365081efbbcbfa75f0c1bbe7)
by [Unito](https://www.unito.io)
Follow up on https://github.com/Comfy-Org/ComfyUI_frontend/pull/6317:
Fixes confusing "merge conflicts detected" message when commit already
exists on target branch (e.g., PRs #6294 and #6307).
## Changes
- Added check to detect if merge commit already exists on target branch
before attempting cherry-pick
- New failure reason `already-exists` for this case
- Clear comment message: "Commit already exists on branch, no backport
needed" instead of confusing "Merge conflicts detected" with empty file
list
## Before
When a commit already existed on the target branch, users would see:
> @user Backport to `core/1.30` failed: Merge conflicts detected.
> Please manually cherry-pick commit `abc123` to the `core/1.30` branch.
> <details><summary>Conflicting files</summary>
>
> </details>
This was confusing because there were no actual conflicts - the commit
was already present.
## After
Users now see:
> @user Commit `abc123` already exists on branch `core/1.30`. No
backport needed.
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6326-ci-leave-comment-and-abort-early-if-commit-already-exists-on-target-branch-in-backport-w-2996d73d36508167aff3e6783e832c74)
by [Unito](https://www.unito.io)
Changes the RC minor version branch release automation to create paired
`core/x.y` and `cloud/x.y` branches whenever a release bump merges.
Then changes the backport workflow to accept labels that match those
branch names directly, allowing engineers to route fixes to either OSS
or cloud release lines without extra labels or artifacts.
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6321-ci-automate-cloud-release-branch-tagging-2996d73d365081b0b036ebd3f088354b)
by [Unito](https://www.unito.io)
## Summary
Expands the PR backport workflow so maintainers can target any release
branch using labels, instead of being limited to the `core/x.y` release
lines. The workflow now collects labels formatted as plain version
numbers (`1.24`) as before, plus new prefixes like
`branch:release/hotfix` or `backport:partner/foo`, validates that each
referenced branch exists, and then cherry-picks the source merge commit
to every target.
All generated PRs and failure comments reference the actual branch name,
making it clear where the backport landed or why it failed. This keeps
the existing opt-in flow (`needs-backport`) but makes it flexible enough
for custom support and partner branches without extra manual work.
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6108-ci-extend-backport-workflow-to-work-with-arbitrary-branches-28f6d73d365081bf85a3d4c40a23bb68)
by [Unito](https://www.unito.io)
