fix(merge-gate): accept a queue base branch that contains slashes

.github/scripts/merge-gate.mjs

@@ -44,10 +44,16 @@ const HOLD = 'hold'
 // (runs 39602546475, 39602806953, 39653640861, 39694988559, 39696278650 — all five failed with
 // "cannot read a pull request from head_ref" before this prefix was accepted, so the gate never once
 // judged a queue entry). Accept both spellings rather than depend on which one the event carries.
+//
+// The base branch is not a single segment: a queue built on `release/1.0` yields
+// `gh-readonly-queue/release/1.0/pr-<N>-<sha>` (#655, run 39694988559's documented shape), so the base
+// is matched greedily up to the final `/pr-…` and may contain slashes. Everything that made the old
+// single-segment pattern refuse still refuses: a non-`gh-readonly-queue/` ref, a missing or
+// non-numeric PR number, and a tail that is not 7–40 hex characters.
 export function prFromHeadRef(ref) {
   const branch = String(ref ?? '').trim().replace(/^refs\/heads\//i, '')
-  const m = /^gh-readonly-queue\/[^/]+\/pr-(\d+)-([0-9a-f]{7,40})$/i.exec(branch)
-  return m ? { pr: Number(m[1]), base: m[2].toLowerCase() } : null
+  const m = /^gh-readonly-queue\/(.+)\/pr-(\d+)-([0-9a-f]{7,40})$/i.exec(branch)
+  return m ? { pr: Number(m[2]), base: m[3].toLowerCase() } : null
 }
 
 const names = (labels) => (labels ?? []).map((l) => String(typeof l === 'string' ? l : l?.name ?? '').toLowerCase())

.github/scripts/merge-gate.test.mjs

@@ -36,6 +36,17 @@ test('#652 follow-up: a head_ref that carries refs/heads/ still names the queue
   assert.equal(prFromHeadRef('refs/tags/gh-readonly-queue/main/pr-566-' + HEAD), null, 'only a branch ref is a queue entry')
 })
 
+test('#655: a queue base that contains slashes still names the pull request', () => {
+  assert.deepEqual(prFromHeadRef('gh-readonly-queue/release/1.0/pr-652-abc1234'), { pr: 652, base: 'abc1234' })
+  assert.deepEqual(prFromHeadRef('refs/heads/gh-readonly-queue/release/1.0/pr-652-abc1234'), {
+    pr: 652,
+    base: 'abc1234',
+  })
+  assert.equal(prFromHeadRef('gh-readonly-queue/release/1.0/pr-652-not-a-sha'), null, 'a multi-segment base does not relax the hex tail')
+  assert.equal(prFromHeadRef('gh-readonly-queue//pr-652-abc1234'), null, 'an empty base names no entry')
+  assert.equal(prFromHeadRef('gh-readonly-queue/release/1.0/pr-abc1234'), null, 'the tail must carry a PR number')
+})
+
 test('a PASS at the merged head lets the entry through', () => {
   const r = judgeAt()
   assert.equal(r.ok, true)