GitLab component: commit what the run wrote, and open the first merge request

[pavel-te]

Two defects in templates/translate/template.yml, both there since it was written. The GitHub half lost the second one in #11; this one had kept both.

1. The first run opened no merge request

The guard was ! git diff --quiet, evaluated before staging. git diff looks only at tracked files, and on a first run every translation is a new file:

first run, translations are NEW files:
  git diff --quiet          -> exit 0   ("nothing changed")
  git add -A
  git diff --cached --quiet -> exit 1   (the index knows better)

So the block was skipped, nothing was pushed, and the job went green having produced nothing. The second run worked — which is why it survived this long. Same defect the CLI fixed upstream in ptc-cli #15.

2. git add -A committed the whole working directory

Anything the caller's job dirtied before us shipped inside a merge request titled "Update translations from PTC".

What replaces them

The working tree is recorded before the CLI runs and compared afterwards; only what differs is staged. By content, not timestamps — the CLI unpacks from a ZIP, and unzip restores mtimes from the archive, so a translation written moments ago can be dated before the run began.

A run that wrote nothing commits nothing and pushes nothing, instead of pushing an empty branch. Paths are staged one at a time under GIT_LITERAL_PATHSPECS, because git add -- <path> takes a pathspec: a translation written to messages[1].json would otherwise stage the caller's messages1.json and exit 0.

Where the shell lives

lib/gitlab-scope.sh — that is where it is tested. A component ships YAML only and cannot vendor a sibling file, so the template inlines it, and one of the tests fails if the two drift apart.

POSIX throughout: the component runs on alpine:3.22, i.e. busybox ash until before_script installs bash.

Verification

tests/gitlab-scope.test.sh — 8 cases: first run, a workspace dirtied beforehand, nothing written, a rewritten file next to an untouched one, ignored files, a path with a space, a glob metacharacter, and the template/library drift check.

Green under bash, dash and busybox ash (the last in a real alpine:3.22 container). CI runs bash and dash.

Mutation-checked: restoring the old git diff --quiet guard fails 5 of 8; restoring git add -A fails 6 of 8.

Unchanged and re-run: 19 unit cases, 5 act jobs, shellcheck clean, the component template still parses.