gitea_get_branch_head_sha() looked up a branch's head SHA via
`curl -fsSL .../branches/<branch>`. For a branch not yet pushed to the
remote, Gitea returns 404, curl -f fails, stdin is empty, and the
downstream `json.load` raises JSONDecodeError -- crashing the guard.
Since ci-queue-wait.sh is a mandatory pre-push check, every new feature
branch's first push was blocked.
Capture the HTTP status via `curl -sS -w '\n%{http_code}'`:
- 404 -> echo __BRANCH_ABSENT__, return 0 (no in-flight pipeline on a
branch that doesn't exist yet -- queue is clear).
- non-200 -> return 1 (still fail-closed on a genuine API error).
- 200 -> parse the JSON as before (existing-branch behavior unchanged).
The caller checks for the __BRANCH_ABSENT__ sentinel and exits 0 with a
"branch not yet on remote -- queue clear" message.
ci-queue-wait.ps1 had the same bug (Invoke-RestMethod throws on any
non-2xx, including 404, and the catch block exited 1) -- ported the
equivalent fix there via the caught exception's HTTP status code.
Adds a red-first regression harness (test-ci-queue-wait-branch-absent.sh)
covering: 404 branch-absent -> queue clear; 200 existing branch with a
terminal CI state -> unchanged behavior; 500 genuine API error -> still
fail-closed. Verified failing against the unpatched script (crashes with
JSONDecodeError) and passing after the fix. Wired into
package.json's test:framework-shell alongside the existing git-wrapper
regression tests.
Upstreams Mos host-local tooling-patch kit (2026-07-23), Patch 3.
