fix(review-gate): recover prior heads a force-push names but does not record

scripts/publish-review-gate-check.mjs

@@ -347,7 +347,7 @@ function loadForcePushedPriorShas(prNumber) {
       "force-push discontinuity discovery",
     ),
   );
-  const priorHeads = new Map();
+  const rewrites = [];
   let hasUntraceableRewrite = false;
 
   for (const event of flattenPages(timelinePages)) {
@@ -356,28 +356,46 @@ function loadForcePushedPriorShas(prNumber) {
     if (!Number.isFinite(createdAt)) {
       throw new Error("force-push event has no valid creation timestamp");
     }
-    if (!/^[0-9a-f]{40}$/iu.test(event.before_commit_id ?? "")) {
+    // `before_commit_id` is the discarded head and is what continuity wants. GitHub
+    // omits it for every release-please regeneration, which is what made those
+    // rewrites look untraceable and blocked release pull requests indefinitely
+    // (#342). The same event still names `commit_id`, the head the push created, and
+    // durable state published against either head is a check run addressable by its
+    // SHA -- so both are candidate heads to search rather than evidence to discard.
+    //
+    // This recovers continuity; it does not waive it. State found this way is still
+    // required to belong to this pull request, and a rewrite naming neither head
+    // remains untraceable below.
+    const shas = [event.commit_id, event.before_commit_id].filter((sha) =>
+      /^[0-9a-f]{40}$/iu.test(sha ?? ""),
+    );
+    if (shas.length === 0) {
       hasUntraceableRewrite = true;
       continue;
     }
-    const existing = priorHeads.get(event.before_commit_id);
-    if (!existing || createdAt > existing.createdAt) {
-      priorHeads.set(event.before_commit_id, { sha: event.before_commit_id, createdAt });
-    }
+    rewrites.push({ createdAt, shas });
   }
 
-  const orderedPriorHeads = [...priorHeads.values()].sort(
-    (left, right) => right.createdAt - left.createdAt,
-  );
-  for (let index = 1; index < orderedPriorHeads.length; index += 1) {
-    if (orderedPriorHeads[index - 1].createdAt === orderedPriorHeads[index].createdAt) {
+  // Ordering is over events, not SHAs. Two SHAs from one event share its timestamp
+  // and their order is known -- the created head is newer than the discarded one --
+  // so only a tie between distinct events is genuinely ambiguous.
+  rewrites.sort((left, right) => right.createdAt - left.createdAt);
+  for (let index = 1; index < rewrites.length; index += 1) {
+    if (rewrites[index - 1].createdAt === rewrites[index].createdAt) {
       throw new Error("force-push events have ambiguous chronological ordering");
     }
   }
-  return {
-    priorHeads: orderedPriorHeads.map(({ sha }) => sha),
-    hasUntraceableRewrite,
-  };
+
+  const seen = new Set();
+  const priorHeads = [];
+  for (const rewrite of rewrites) {
+    for (const sha of rewrite.shas) {
+      if (seen.has(sha)) continue;
+      seen.add(sha);
+      priorHeads.push(sha);
+    }
+  }
+  return { priorHeads, hasUntraceableRewrite };
 }
 
 function flattenPages(value) {

tests/scripts/publish-review-gate-check.test.ts

@@ -429,6 +429,80 @@ describe("PR-head Review gate check publisher", () => {
     expect(publicationText).not.toContain(rawUrl);
   });
 
+  // #342: the decisive case. release-please force-pushes leave `before_commit_id`
+  // null, so the gate called the rewrite untraceable and refused -- but the same
+  // timeline event carries `commit_id`, the head after the push, which is where the
+  // orphaned durable state lives. Blocking every release pull request to protect
+  // state that was reachable all along is the defect this closes.
+  it("reaches durable state on a head named only by the force-push commit_id", () => {
+    const orphanedSha = "b".repeat(40);
+    const { result, calls } = runScript(
+      ["--reconcile-open-prs", "--max-prs", "1", "--selection-offset", "0"],
+      [pull(1)],
+      cleanReviewFixture(),
+      [{ status: 0 }],
+      null,
+      [{ status: 0 }],
+      { [orphanedSha]: cleanDurableState() },
+      [forcePushEvent(null, "2026-08-17T00:00:00Z", orphanedSha)],
+    );
+    const publicationText =
+      calls.find((call) => call.includes("repos/lamemustafa/pack/check-runs"))?.join(" ") ?? "";
+
+    expect(
+      calls.some((call) => call.join(" ").includes(`commits/${orphanedSha}/check-runs?`)),
+      "the orphaned head named by commit_id must be consulted",
+    ).toBe(true);
+    expect(result.status).toBe(0);
+    expect(publicationText).not.toContain("GitHub did not record the prior head");
+    expect(publicationText).toContain("conclusion=success");
+  });
+
+  // Continuity is recovered, not waived: state found through a recovered head is
+  // still required to belong to this pull request.
+  it("ignores recovered-head state that belongs to another pull request", () => {
+    const orphanedSha = "b".repeat(40);
+    const { result, calls } = runScript(
+      ["--reconcile-open-prs", "--max-prs", "1", "--selection-offset", "0"],
+      [pull(1)],
+      cleanReviewFixture(),
+      [{ status: 0 }],
+      null,
+      [{ status: 0 }],
+      { [orphanedSha]: cleanDurableState(2) },
+      [forcePushEvent(null, "2026-08-17T00:00:00Z", orphanedSha)],
+    );
+    const publicationText =
+      calls.find((call) => call.includes("repos/lamemustafa/pack/check-runs"))?.join(" ") ?? "";
+
+    expect(
+      calls.some((call) => call.join(" ").includes(`commits/${orphanedSha}/check-runs?`)),
+    ).toBe(true);
+    expect(result.status).toBe(0);
+    expect(publicationText).toContain("conclusion=action_required");
+  });
+
+  // The other half of the premise: a rewrite with neither field usable must stay
+  // untraceable. Whatever widening happens must not make this reachable.
+  it("stays untraceable when neither before_commit_id nor commit_id is usable", () => {
+    const { result, calls } = runScript(
+      ["--reconcile-open-prs", "--max-prs", "1", "--selection-offset", "0"],
+      [pull(1)],
+      cleanReviewFixture(),
+      [{ status: 0 }],
+      null,
+      [{ status: 0 }],
+      { ["c".repeat(40)]: cleanDurableState() },
+      [forcePushEvent(null, "2026-08-17T00:00:00Z", null)],
+    );
+    const publicationText =
+      calls.find((call) => call.includes("repos/lamemustafa/pack/check-runs"))?.join(" ") ?? "";
+
+    expect(result.status).toBe(0);
+    expect(publicationText).toContain("conclusion=action_required");
+    expect(publicationText).toContain("GitHub did not record the prior head");
+  });
+
   it("publishes a re-creation remedy instead of seeding state across an untraceable rewrite", () => {
     const orphanedSha = "b".repeat(40);
     const { result, calls } = runScript(
@@ -780,10 +854,18 @@ function reviewStateWithDeletedFinding(
   );
 }
 
-function forcePushEvent(beforeCommitId: string | null, createdAt = "2026-08-17T12:00:00Z") {
+function forcePushEvent(
+  beforeCommitId: string | null,
+  createdAt = "2026-08-17T12:00:00Z",
+  commitId: string | null = null,
+) {
+  // Real events carry `commit_id` -- the head *after* the push -- even when
+  // `before_commit_id` is null. Verified on #337, where all three release-please
+  // force-pushes have a null `before_commit_id` and a populated `commit_id`.
   return {
     event: "head_ref_force_pushed",
     before_commit_id: beforeCommitId,
+    ...(commitId === null ? {} : { commit_id: commitId }),
     created_at: createdAt,
   };
 }