The branch patch checkout creates can never stamp a Patch: trailer, so revisions merge unrecorded

open   by a73x

Labels: backlog

[claude 2026-08-15] `patch checkout <id>` puts you on `collab/<id>`. The commit-msg hook stamps only when an open patch's recorded `branch` field equals the current branch (src/hooks.rs:307-325), and that field holds the branch the patch was *created* from — never `collab/<id>`. So the hook is silent by construction on the branch the tool itself just told you to use.

```
$ git-collab patch checkout 01ad09e5
Checked out patch 01ad09e5 (revision 1) on branch collab/01ad09e5; you were on main.
$ git-collab hooks status
commit-msg hook: installed (...)
HEAD is on 'collab/01ad09e5': no open patch records this branch, so nothing would be stamped
$ git commit -m "address feedback"      # no Patch: trailer
$ git checkout main && git merge --no-ff collab/01ad09e5 && git-collab sync
1 patch(es) look merged but are not recorded:
  01ad09e5  add feature
Record one with: git-collab patch merge <id>
```

The merge is detected but not recorded, and the `--fixes` issue stays open until someone runs `patch merge` by hand. On the original branch the same sequence stamps and `sync` records it automatically, so the automatic path works exactly until you use `patch checkout` to get the code back.

src/hooks.rs:298-304 already documents the general weakness — an ephemeral or renamed branch does not match, and silence is the right answer over guessing. This is narrower than that: `collab/<id>` is a name the tool generates itself, from the id it is trying to match. It is the one case where the branch name is not ambiguous provenance but a derivable fact, so silence is not forced here the way it is for a user's renamed branch.

Cheapest fix is probably for `patch checkout` to record the branch it creates (or for the hook to recognise the `collab/<id>` form and resolve the id directly), so that the revise → merge path records itself like the create → merge path does.

Found while verifying the git-collab skill's documented workflow; the skill now warns about it as a trap.