Commit Graph
4 Commits
Author SHA1 Message Date
timothy 8f6d4f4432 fix(706,707,711): fence the review-verdict write on the timeline retarget count
PR Gates / CI image pin matches docker/ci (pull_request) Successful in 11s
PR Gates / Docs update reminder (pull_request) Successful in 15s
PR Gates / decisions lifecycle (pull_request) Successful in 23s
Build ErsatzTV Image / API docs in sync (OpenAPI + endpoint index) (pull_request) Successful in 23s
review-verdict/h10 Awaiting review verdict for 8f6d4f4
Review verdict / Set review-verdict status (pull_request_target) Successful in 20s
PR Gates / Script tests (pytest) (pull_request) Successful in 1m29s
Build ErsatzTV Image / Formatting (changed .cs conform to .editorconfig) (pull_request) Successful in 1m26s
Build ErsatzTV Image / Functional E2E (curl + UI contracts) (pull_request) Successful in 16m56s
Build ErsatzTV Image / EF migration integrity (SQLite + MySql) (pull_request) Successful in 20m59s
Build ErsatzTV Image / Build & test (.NET) (pull_request) Successful in 22m41s
Build ErsatzTV Image / Build & push image (amd64) (pull_request) Has been skipped
Three related defects in the `review-verdict/h10` gate, all surfaced by the
cross-family review of PR #705.

#706 race 1 — a stale run could overwrite a fresher verdict, permanently. The
race was reproduced live rather than reasoned about (Gitea 1.25.4): with every
other workflow stripped, probe PR #722 showed run 7520 (`opened`) finishing 20s
AFTER run 7521 (`synchronize`) started. `pull_request_target` runs for one PR
genuinely overlap, older finishing last.

The issue proposed serializing with a non-cancelling concurrency group. That is
REFUTED by measurement: with the group active, runs 7528/7529 still overlapped
and 7528 ended 36s after 7529 began. A first probe appeared to show the group
working — a negative control with no `concurrency:` key at all showed the same
cancellations, revealing Gitea auto-cancels superseded `push` runs on its own
and the probe had measured that, not the group. The auto-cancel does not extend
to `pull_request_target`.

The fix leaves the runs unserialized and instead makes an overtaken run decline
to write: count `change_target_branch` events on the PR timeline at start and
again just before the POST, and post nothing if the count moved. The COUNT is
the key because the branch NAME is ABA-vulnerable (`main -> S -> main` reads
`main` at both ends — how #698 route 1 forged its exemption). Abstaining is a
handoff, not a stall: every retarget fires `edited`, so the event that makes a
run abstain has already queued its successor. `updated_at` was rejected as the
key precisely because it moves for comments/labels, which queue nothing.

#706 race 2 — a human BLOCKED landing in the unclosable window between the
pre-POST re-read and the POST was silently turned green. After an exemption
`success` the job now re-reads the per-POST history and repairs its own status
to `pending` if a human verdict appeared above a high-water mark taken just
before the write. The repair is `pending`, never a copy of the human's state.
The id comparison is load-bearing: a presence test would fire forever on a
base-mismatched verdict and deadlock that PR's exemption.

#707 — `pr-changed-files.sh` bound `.base.ref` and `.head.sha` across the
enumeration but never `.base.sha`, so an ordinary advance of `main` mid-paging
could drop a code path from an offset-paged diff and leave a complete-looking
docs-only list. Now bound from the JSON already fetched (no new round trips).

#711 — `.codex/` added to PROTECTED. It mirrors `.claude/hooks/` byte for byte,
including the merge-consent hook, so the "a PR that can weaken the gate cannot
exempt itself" rule had an incomplete path list. Latent today (untracked), live
the moment anyone tracks it.

Residuals are stated, not implied: a retarget inside the final round-trip, and
the repair being itself a read-then-write. Gitea's status API has no
compare-and-set, so neither reaches zero; both now fail toward `pending`.

Tests: 398 pass in scripts/tests. Each new guard was mutation-checked — the
fence's motion comparison, the untrusted-count gate, the repair POST and the id
high-water mark were each neutered in turn and the intended test went red while
its positive control stayed green.

fixes #706
fixes #707
fixes #711

Decisions-Edit: yes
2026-08-03 21:41:16 +02:00
timothyandClaude Opus 5 f523fc535d fix(698): bind the base, constrain the bot exemption by content, re-derive unattributable successes
PR Gates / decisions lifecycle (pull_request) Successful in 24s
PR Gates / CI image pin matches docker/ci (pull_request) Successful in 27s
PR Gates / Docs update reminder (pull_request) Successful in 28s
Review verdict / Set review-verdict status (pull_request_target) Successful in 17s
PR Gates / Script tests (pytest) (pull_request) Successful in 1m1s
Build ErsatzTV Image / Functional E2E (curl + UI contracts) (pull_request) Successful in 6m9s
Build ErsatzTV Image / API docs in sync (OpenAPI + endpoint index) (pull_request) Successful in 9s
Build ErsatzTV Image / Formatting (changed .cs conform to .editorconfig) (pull_request) Successful in 7s
Build ErsatzTV Image / EF migration integrity (SQLite + MySql) (pull_request) Successful in 17m8s
review-verdict/h10 Review-verdict: BLOCKED @ f523fc5 (base: main)
Build ErsatzTV Image / Build & test (.NET) (pull_request) Successful in 23m34s
Build ErsatzTV Image / Build & push image (amd64) (pull_request) Has been skipped
The `review-verdict/h10` exemption path decided from mutable or unattributed PR
state, and a machine-written `success` was never revalidated. Three routes, one
root cause, so one change.

Route 1 (reproduced live as probe PR #703, closed unmerged): `/pulls/{n}/files`
diffs against the PR's LIVE base, so retargeting moves the answer without moving
the head sha. A PR opened into `main` and retargeted mid-run enumerated docs-only
and was granted `h10=success` while its diff against `main` carried a C# file;
retargeting back reclassified nothing. `scripts/pr-changed-files.sh` now takes the
expected base branch as a REQUIRED 5th argument (optional would be a silent
opt-out) and checks it before and after paging; the workflow passes it from the
`pull_request_target` payload, which a retarget cannot rewrite, and `edited` is in
`types:` so a retarget reclassifies.

A pinned two-sha diff would close route 1 outright but Gitea 1.25.4 cannot serve
one: `compare/{base}...{head}` returns no `files`, and a `--depth=1` fetch of the
two shas has no merge base. Measured, not assumed. The residual window is stated
in the code and the record rather than papered over.

Route 2: `pull_request.user.login` is the PR's immutable CREATOR while its head is
not, so pushing code onto an open Renovate branch kept the exemption. The bot
exemption now also requires EVERY path to be a dependency manifest — a set measured
across all 11 Renovate PRs this repo has had, not guessed.

Route 3: the never-overwrite short-circuit exited on ANY `success`, so a forgery
obtained once was inherited forever. It now fires only for a status positively
identified as a human verdict (non-null `.creator.login` AND a `Review-verdict:`
description — measured: user-posted statuses carry a creator, Actions-posted ones
carry null). Written in the positive direction so an unrecognised shape is
re-derived rather than trusted.

The two exemptions are composed, not chained: as an `elif` chain a Renovate
docs-only PR lost the docs-only exemption. Caught before commit and pinned by a
test.

Tests: 17 new cases in scripts/tests/test_pr_changed_files.py, each verified by
mutating the clause it covers (8 mutations, 8 kills). Both records trimmed under
the 60-line prose ceiling so the corpus tail-boundary check stays calibrated.

Does NOT close the class: anyone who can POST a status directly can still
impersonate a verdict — that is #697, deliberately left open.

Refs: #698
Decisions-Edit: yes
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-29 19:52:00 +02:00
timothy 5e7623b8d5 fix(648,649): security-review round 2 — close the version-parse hole and the untested caller contract
Two real defects, and three docs claims that were simply wrong.

jq-preflight.sh parsed the version by stripping around the first `-` and `.`, which
assumed the format is exactly `jq-X.Y`. A build printing `jq version 1.6` left major
empty; the sanity check concatenated major+minor into "6", which is non-empty and
all-digits, so it PASSED. The floor comparison then ran `[ "" -lt 1 ]`, which errors —
and `set -e` exempts a failing command in an `if` condition, so the conditional read
false and the script exited 0 having asserted nothing, after printing a plausible
"parsed" line. The silently-untested-axis failure this script exists to eliminate,
reproduced inside the script itself. Now parsed by explicit regex, failing closed with a
diagnosis when there is no <digits>.<digits> match. Also: `--expect` with no value exited
1 with empty output on both streams.

The hook's exit-status check was pinned by nothing: mutating `if files=$(...)` into
`files=$(...) || true; files_complete=yes` left the ENTIRE suite green. It survived only
by redundancy — the script writes stdout once, right before exit 0, so failures also
happen to yield empty stdout and `[ -n "$files" ]` catches it. Safe by accident, which is
the exact criticism this branch levels at the old code. Four tests now pin it, with a
stub that FAILS while emitting a docs-only list (the one case redundancy cannot absorb)
plus a positive control proving the harness can see the difference. Verified: the
mutation now turns exactly those tests red.

Docs corrections. The record claimed the --expect pin was safe because script-tests is
"advisory, not a required check" — false. The merge-consent hook reads the COMBINED
status (ci.advisory-red-blocks-the-merge-gate, #598), so firing the tripwire blocks every
non-docs-only merge until someone re-pins. Kept anyway, for a stated reason, but no
longer described as free. The record also asserted in the present tense that
review-verdict.yml checks out the base ref; it has no checkout step at all, so that is
now a future-tense requirement on the follow-up. And the documented .status allow-list
named GitHub's `removed`, which the code rejects.

The drift-guard regex anchored on `?limit=`, so a re-inlined copy written
`files?page=1&limit=50` would have walked past it.

Decisions-Edit: yes
2026-07-26 22:21:07 +02:00
timothy 2fd798cccf fix(648,649): one shared PR-file enumeration + an explicit jq version contract
#649 — the enforced review-verdict.yml guard had drifted strictly WEAKER than the
advisory merge-consent hook: four rounds of #643 hardening landed on the copy whose
failures produce a human prompt, and never reached the copy that writes the
branch-protection-required review-verdict/h10 status. Its fail-closed behaviour on a
garbage response was also incidental (an empty `n` erroring a bash conditional to
false), not designed.

Extract scripts/pr-changed-files.sh as the single implementation both call. Shared
MECHANISM, not policy: the two docs-only allow-lists differ deliberately and stay
separate. review-verdict.yml now checks out the BASE ref, never the PR head, so a PR
cannot rewrite the gate that judges it.

#648 — baking jq into docker/ci/Dockerfile provably cannot cover the gate that broke:
review-verdict.yml is runs-on:small with no toolchain pin, so it gets the host's jq 1.6
(checked, not assumed). Add scripts/jq-preflight.sh: floor+observable everywhere, and a
--expect tripwire on script-tests only — pinning the required merge check would deadlock
every merge on a jq bump.

Verified by mutation: six guards individually broken, each turning exactly its own test
red, then restored byte-identical.

fixes #648
fixes #649
2026-07-26 22:21:07 +02:00