fix(gate): preserve exact-owner renewal evidence across duplicate rechecks (Closes #945)

An exact-owner lease renewal (#760) is granted the owning-PR duplicate-work
waiver inside gitea_lock_issue, but every later enforcement path rebuilt that
proof from the durable lock through
issue_lock_recovery.recovered_owning_pr_from_lock, which reads only the
dead_session_recovery block. A plain renewal persists its proof under
lease_renewal instead, so the waiver expired with the lock call and the next
author mutation was refused duplicate_commit_prevented with
owning_pr_recovery_exempted: false on the very PR the renewal had just proved.

Add issue_lock_renewal.owning_pr_renewal_from_lock as the renewal mirror of the
recovery rebuild, and resolve both halves through one helper,
_owning_pr_continuation_from_lock, in the same precedence gitea_lock_issue
applies. The three enforcement paths that previously saw only recovery evidence
now share that resolver: the commit/create-PR duplicate recheck, the read-only
duplicate assessor, and the push-ownership prover.

The rebuild re-applies the equality the renewal assessor required (PR head ==
local head == remote head) and additionally binds the record to the claimant the
lock names, so a renewal block cannot be reused under another identity, profile,
or workflow session. Validation of the resulting token against live PR state is
unchanged and still owned solely by
issue_work_duplicate_gate._assess_owning_pr_exemption, so repository, issue, PR,
branch and head binding continue to be enforced in exactly one place.

No public signature, MCP tool schema, refusal shape, or reason code changes.
Dead-session recovery behaviour is untouched.

Tests: tests/test_issue_945_owning_pr_renewal_continuation.py - 49 tests,
8 subtests, all in-memory (no durable branch, worktree, lock, lease or PR).
Against unmodified aab54d48 the suite is 47 failed / 2 passed; the 2 that pass
are the defect-pinning reproductions. Full suite 28F/5574P/6S/1002 subtests at
head vs 28F/5525P/6S/994 at base, with identical failing test id sets.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

gitea_mcp_server.py

@@ -2781,6 +2781,36 @@ def _collect_issue_duplicate_context(
     return issue_duplicate_context_fetcher(h, o, r, auth, issue_number)
 
 
+def _owning_pr_continuation_from_lock(lock_record: dict | None) -> dict | None:
+    """Owning-PR continuation evidence a persisted lock still proves (#945).
+
+    ``gitea_lock_issue`` grants the duplicate-work waiver from either a
+    sanctioned dead-session recovery (#755) or a sanctioned exact-owner renewal
+    (#760), in that precedence. Every later enforcement path — commit,
+    create-PR, push-ownership, and the read-only duplicate assessor — re-derives
+    ownership from the durable lock instead of that live assessment.
+
+    Until #945 only the recovery half was rebuilt there, so an ordinary
+    exact-owner renewal lost its waiver the moment ``gitea_lock_issue``
+    returned: the author renewed successfully and was then refused
+    ``duplicate_commit_prevented`` with ``owning_pr_recovery_exempted: false``
+    on the very PR the renewal had just proved it owned.
+
+    Resolving both halves here, in the same precedence the lock path applies,
+    keeps the answer from drifting between the gate that grants the waiver and
+    the gates that enforce it. This only decides which server-written block the
+    token is rebuilt from — the token is still re-validated against live PR
+    state by ``issue_work_duplicate_gate._assess_owning_pr_exemption``, which
+    remains the single authoritative policy for whether an exemption applies.
+    """
+    if not lock_record:
+        return None
+    recovered = issue_lock_recovery.recovered_owning_pr_from_lock(lock_record)
+    if recovered:
+        return recovered
+    return issue_lock_renewal.owning_pr_renewal_from_lock(lock_record)
+
+
 def _assess_issue_duplicate_gate(
     issue_number: int,
     *,
@@ -2833,6 +2863,11 @@ def _enforce_locked_issue_duplicate_recheck(
     commit and create-PR phases run in their own calls, long after the recovery
     assessment ended, so without this they re-block the very PR the recovery
     already proved belongs to this author.
+
+    #945: an exact-owner *renewal* (#760) owns its open PR for exactly the same
+    reason, and ``gitea_lock_issue`` already waives the blocker for both. Both
+    halves are resolved together here so the renewal waiver survives past the
+    lock call instead of expiring with it.
     """
     lock_data = _load_existing_issue_lock()
     if not lock_data:
@@ -2856,9 +2891,7 @@ def _enforce_locked_issue_duplicate_recheck(
         auth=auth,
         locked_branch=locked_branch,
         phase=phase,
-        recovered_owning_pr=issue_lock_recovery.recovered_owning_pr_from_lock(
+        recovered_owning_pr=_owning_pr_continuation_from_lock(lock_data),
-            lock_data
-        ),
     )
     if gate.get("block"):
         return gate
@@ -5140,9 +5173,10 @@ def gitea_assess_work_issue_duplicate(
     recovered_owning_pr = None
     lock_data = _load_existing_issue_lock()
     if lock_data and int(lock_data.get("issue_number") or 0) == int(issue_number):
-        recovered_owning_pr = issue_lock_recovery.recovered_owning_pr_from_lock(
+        # #945: rebuilt from a sanctioned recovery *or* a sanctioned exact-owner
-            lock_data
+        # renewal, so this read-only assessor reports the same disposition the
-        )
+        # commit and create-PR gates will enforce.
+        recovered_owning_pr = _owning_pr_continuation_from_lock(lock_data)
     gate = _assess_issue_duplicate_gate(
         issue_number,
         h=h,
@@ -19424,7 +19458,10 @@ def _prove_author_ownership_for_pr(
     # advance is the one recovery already sanctioned, not a foreign head.
     recovered_owning_pr = None
     if proven and lock_record:
-        candidate = issue_lock_recovery.recovered_owning_pr_from_lock(lock_record)
+        # #945: a sanctioned exact-owner renewal proves the same ownership of
+        # the same PR, so the push gate resolves both halves rather than seeing
+        # only the recovery one.
+        candidate = _owning_pr_continuation_from_lock(lock_record)
         if candidate and int(candidate.get("pr_number") or 0) == int(pr_number):
             recovered_owning_pr = candidate
     return {

issue_lock_renewal.py

@@ -436,6 +436,90 @@ def owning_pr_renewal_evidence(
     }
 
 
+def owning_pr_renewal_from_lock(
+    lock_record: Mapping[str, Any] | None,
+) -> dict[str, Any] | None:
+    """Rebuild owning-PR renewal evidence from a persisted lock (#945).
+
+    The renewal mirror of ``issue_lock_recovery.recovered_owning_pr_from_lock``.
+    ``owning_pr_renewal_evidence`` supplies the waiver for the duration of the
+    ``gitea_lock_issue`` call only. The commit, push, create-PR, and
+    duplicate-assessment gates run later in their own calls and re-derive
+    ownership from the durable lock instead — so without this the open PR that
+    renewal already proved belongs to this author reappears there as competing
+    duplicate work, and the exact owner is refused with
+    ``duplicate_commit_prevented`` despite complete matching evidence.
+
+    This reads only the ``lease_renewal`` block that the server itself writes,
+    on a lock the caller must already own. Like the recovery mirror it is a
+    re-read of server-derived state, never a fresh assertion: a caller able to
+    forge it could equally forge the lock file every other ownership gate
+    already treats as authoritative.
+
+    Renewal has no descendant case — the assessor required the local, remote and
+    PR heads to be equal — so that equality is re-checked here, and the record
+    must still name the claimant the lock records.
+    """
+    if not isinstance(lock_record, Mapping):
+        return None
+    record = lock_record.get("lease_renewal")
+    if not isinstance(record, Mapping) or not record.get("renewed"):
+        return None
+
+    branch_name = _text(record.get("branch_name")) or _text(
+        lock_record.get("branch_name")
+    )
+    pr_head = _text(record.get("pr_head_sha"))
+    local_head = _text(record.get("head_sha"))
+    remote_head = _text(record.get("remote_head_sha"))
+    raw_pr_number = record.get("pr_number")
+    raw_issue_number = lock_record.get("issue_number")
+
+    if raw_pr_number is None or raw_issue_number is None:
+        return None
+    if not branch_name or not pr_head:
+        return None
+    # The assessor required all three heads to agree before it granted renewal.
+    # Re-check, so a truncated, drifted, or hand-built record cannot widen the
+    # exemption past the single head the renewal disposition actually proved.
+    if not local_head or not remote_head:
+        return None
+    if pr_head != local_head or pr_head != remote_head:
+        return None
+    # Renewal is refused outright unless the durable lock records both a
+    # claimant username and profile, so a sanctioned record always carries them.
+    # Requiring them to still agree keeps a renewal block from being reused
+    # under an identity or profile the lock no longer names.
+    claimant = lock_record.get("claimant")
+    if not isinstance(claimant, Mapping):
+        lease = lock_record.get("work_lease")
+        claimant = lease.get("claimant") if isinstance(lease, Mapping) else None
+    if not isinstance(claimant, Mapping):
+        return None
+    identity = _text(record.get("identity"))
+    profile = _text(record.get("profile"))
+    if not identity or identity != _text(claimant.get("username")):
+        return None
+    if not profile or profile != _text(claimant.get("profile")):
+        return None
+
+    try:
+        pr_number = int(raw_pr_number)
+        issue_number = int(raw_issue_number)
+    except (TypeError, ValueError):
+        return None
+
+    return {
+        "issue_number": issue_number,
+        "pr_number": pr_number,
+        "branch_name": branch_name,
+        "head_sha": pr_head,
+        "recorded_head": pr_head,
+        "accepted_head": pr_head,
+        "head_relation": "equal",
+    }
+
+
 def build_renewal_record(
     assessment: Mapping[str, Any] | None,
     *,

tests/test_issue_945_owning_pr_renewal_continuation.py

@@ -0,0 +1,465 @@
+import sys as _sys
+from pathlib import Path as _Path
+_sys.path.insert(0, str(_Path(__file__).resolve().parent))
+from mutation_profile_fixture import shared_mutation_env  # noqa: F401,E402
+"""Exact-owner renewal keeps its owning-PR waiver past lock_issue (#945).
+
+#755 taught the duplicate-work gate that a sanctioned *dead-session recovery*
+owns its open PR, and #768 taught the later gates to rebuild that proof from the
+durable lock. #760 added the exact-owner *renewal* disposition and granted it
+the same waiver inside ``gitea_lock_issue`` — but never added the matching
+rebuild. So an ordinary renewal held the waiver only for the duration of the
+lock call: ``_enforce_locked_issue_duplicate_recheck`` asked
+``recovered_owning_pr_from_lock``, which reads only ``dead_session_recovery``,
+and the very next commit was refused ``duplicate_commit_prevented`` with
+``owning_pr_recovery_exempted: false`` on the PR the renewal had just proved.
+
+``TestPreFixReproduction`` pins that defect directly: the recovery-only rebuild
+still returns ``None`` for a renewal lock, which is exactly why the gates lost
+the waiver. Everything else proves the renewal half now survives, that recovery
+is unchanged, and that no path grants an exemption on weaker evidence.
+
+Every fixture here is an in-memory mapping. Nothing writes a branch, worktree,
+lock file, lease, comment, or PR (#945 AC18).
+"""
+import copy
+import sys
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import gitea_mcp_server  # noqa: E402
+import issue_lock_recovery  # noqa: E402
+import issue_lock_renewal  # noqa: E402
+from issue_work_duplicate_gate import (  # noqa: E402
+    OUTCOME_DUPLICATE_WORK_NOT_PREVENTED,
+    PHASE_COMMIT,
+    PHASE_CREATE_PR,
+    PHASE_LOCK,
+    PHASE_PUSH,
+    assess_work_issue_duplicate_gate,
+)
+
+ISSUE = 4945
+OWNING_PR = 4946
+OTHER_PR = 4947
+BRANCH = f"fix/issue-{ISSUE}-owning-pr-renewal"
+OTHER_BRANCH = f"fix/issue-{ISSUE}-competing"
+HEAD = "a" * 40
+OTHER_HEAD = "b" * 40
+IDENTITY = "example-user"
+PROFILE = "test-author-prgs"
+
+
+def renewal_record(**overrides):
+    """The ``lease_renewal`` block ``build_renewal_record`` writes on success."""
+    record = {
+        "renewed": True,
+        "renewed_at": "2026-01-01T00:00:00Z",
+        "prior_pid": 4242,
+        "prior_pid_alive": True,
+        "prior_expires_at": "2026-01-01T00:00:00Z",
+        "replacement_pid": 4243,
+        "new_expires_at": "2026-01-01T00:10:00Z",
+        "identity": IDENTITY,
+        "profile": PROFILE,
+        "branch_name": BRANCH,
+        "worktree_path": f"branches/issue-{ISSUE}-owning-pr-renewal",
+        "head_sha": HEAD,
+        "remote_head_sha": HEAD,
+        "pr_head_sha": HEAD,
+        "pr_number": OWNING_PR,
+        "reason": "expired lease renewed by its exact recorded owner",
+        "proof": [],
+    }
+    record.update(overrides)
+    return record
+
+
+def renewal_lock(record=None, *, issue_number=ISSUE, claimant=True, **lock_overrides):
+    lock = {
+        "issue_number": issue_number,
+        "branch_name": BRANCH,
+        "lease_renewal": renewal_record() if record is None else record,
+    }
+    if claimant:
+        lock["claimant"] = {"username": IDENTITY, "profile": PROFILE}
+    lock.update(lock_overrides)
+    return lock
+
+
+def recovery_lock(pr_number=OWNING_PR, head=HEAD):
+    """A lock carrying sanctioned dead-session recovery evidence (#755/#768)."""
+    return {
+        "issue_number": ISSUE,
+        "branch_name": BRANCH,
+        "claimant": {"username": IDENTITY, "profile": PROFILE},
+        "dead_session_recovery": {
+            "recovered": True,
+            "branch_name": BRANCH,
+            "pr_number": pr_number,
+            "pr_head": head,
+            "recorded_head": head,
+            "accepted_head": head,
+            "head_relation": issue_lock_recovery.HEAD_RELATION_EQUAL,
+        },
+    }
+
+
+def owning_pr(number=OWNING_PR, ref=BRANCH, sha=HEAD, issue=ISSUE):
+    return {
+        "number": number,
+        "title": f"fix: something (Closes #{issue})",
+        "body": f"Closes #{issue}.",
+        "head": {"ref": ref, "sha": sha},
+    }
+
+
+def gate(phase, *, token, open_prs=None, branch_names=None, locked_branch=BRANCH):
+    return assess_work_issue_duplicate_gate(
+        ISSUE,
+        open_prs=[owning_pr()] if open_prs is None else open_prs,
+        branch_names=branch_names or [],
+        claim_entry={},
+        locked_branch=locked_branch,
+        phase=phase,
+        recovered_owning_pr=token,
+    )
+
+
+# ───────────────────── the defect this issue exists to fix ─────────────────────
+
+
+class TestPreFixReproduction(unittest.TestCase):
+    """The exact wiring gap: renewal evidence was invisible to later gates."""
+
+    def test_recovery_only_rebuild_cannot_see_a_renewal_lock(self):
+        # This is the pre-fix behaviour of every enforcement path. It is correct
+        # for the recovery rebuild to ignore a renewal block -- the defect was
+        # that nothing else looked at it.
+        self.assertIsNone(
+            issue_lock_recovery.recovered_owning_pr_from_lock(renewal_lock())
+        )
+
+    def test_renewal_lock_produced_no_exemption_before_the_fix(self):
+        # Feeding the gate what the pre-fix code fed it (recovery rebuild only)
+        # reproduces the reported refusal at the commit phase.
+        token = issue_lock_recovery.recovered_owning_pr_from_lock(renewal_lock())
+        result = gate(PHASE_COMMIT, token=token)
+        self.assertTrue(result["block"])
+        self.assertEqual(result["outcome"], "duplicate_commit_prevented")
+        self.assertFalse(result["owning_pr_recovery_exempted"])
+        self.assertEqual(result["owning_pr_recovery_notes"], [])
+
+    def test_shared_resolver_now_sees_it(self):
+        self.assertIsNotNone(
+            gitea_mcp_server._owning_pr_continuation_from_lock(renewal_lock())
+        )
+
+
+# ───────────────────────── rebuild: the granted case ─────────────────────────
+
+
+class TestRenewalRebuildGranted(unittest.TestCase):
+    def test_sanctioned_renewal_rebuilds_owning_pr_evidence(self):
+        token = issue_lock_renewal.owning_pr_renewal_from_lock(renewal_lock())
+        self.assertEqual(
+            token,
+            {
+                "issue_number": ISSUE,
+                "pr_number": OWNING_PR,
+                "branch_name": BRANCH,
+                "head_sha": HEAD,
+                "recorded_head": HEAD,
+                "accepted_head": HEAD,
+                "head_relation": "equal",
+            },
+        )
+
+    def test_branch_falls_back_to_the_lock_branch(self):
+        lock = renewal_lock(renewal_record(branch_name=""))
+        token = issue_lock_renewal.owning_pr_renewal_from_lock(lock)
+        self.assertEqual(token["branch_name"], BRANCH)
+
+    def test_claimant_may_live_under_work_lease(self):
+        lock = renewal_lock(claimant=False)
+        lock["work_lease"] = {"claimant": {"username": IDENTITY, "profile": PROFILE}}
+        self.assertIsNotNone(issue_lock_renewal.owning_pr_renewal_from_lock(lock))
+
+    def test_rebuild_does_not_mutate_the_lock(self):
+        lock = renewal_lock()
+        before = copy.deepcopy(lock)
+        issue_lock_renewal.owning_pr_renewal_from_lock(lock)
+        self.assertEqual(lock, before)
+
+
+# ───────────────────────── rebuild: fails closed ─────────────────────────
+
+
+class TestRenewalRebuildFailsClosed(unittest.TestCase):
+    def assertNoEvidence(self, lock):
+        self.assertIsNone(issue_lock_renewal.owning_pr_renewal_from_lock(lock))
+
+    def test_no_lock_at_all(self):
+        self.assertNoEvidence(None)
+        self.assertNoEvidence({})
+        self.assertNoEvidence("not-a-mapping")
+
+    def test_lock_without_renewal_block(self):
+        # A fresh claim, or a lock whose renewal block was replaced.
+        self.assertNoEvidence({"issue_number": ISSUE, "branch_name": BRANCH})
+
+    def test_renewal_not_granted(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(renewed=False)))
+
+    def test_renewal_flag_missing(self):
+        record = renewal_record()
+        del record["renewed"]
+        self.assertNoEvidence(renewal_lock(record))
+
+    def test_renewal_block_malformed(self):
+        self.assertNoEvidence(renewal_lock("not-a-mapping"))
+
+    def test_local_head_diverged_from_pr_head(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(head_sha=OTHER_HEAD)))
+
+    def test_remote_head_diverged_from_pr_head(self):
+        # Force-push or unrelated remote movement.
+        self.assertNoEvidence(renewal_lock(renewal_record(remote_head_sha=OTHER_HEAD)))
+
+    def test_local_head_missing(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(head_sha="")))
+
+    def test_remote_head_missing(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(remote_head_sha="")))
+
+    def test_pr_head_missing(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(pr_head_sha="")))
+
+    def test_pr_number_missing(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(pr_number=None)))
+
+    def test_pr_number_malformed(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(pr_number="not-a-number")))
+
+    def test_issue_number_missing_from_lock(self):
+        self.assertNoEvidence(renewal_lock(issue_number=None))
+
+    def test_branch_unknown_everywhere(self):
+        lock = renewal_lock(renewal_record(branch_name=""))
+        lock["branch_name"] = ""
+        self.assertNoEvidence(lock)
+
+    def test_identity_mismatch(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(identity="someone-else")))
+
+    def test_profile_mismatch(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(profile="other-profile")))
+
+    def test_identity_missing(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(identity="")))
+
+    def test_profile_missing(self):
+        self.assertNoEvidence(renewal_lock(renewal_record(profile="")))
+
+    def test_claimant_absent(self):
+        self.assertNoEvidence(renewal_lock(claimant=False))
+
+    def test_evidence_from_a_different_session_is_not_reusable(self):
+        # A renewal block left by another workflow session names another
+        # claimant, so the lock it is found on cannot inherit its authority.
+        lock = renewal_lock()
+        lock["claimant"] = {"username": "other-session-user", "profile": PROFILE}
+        self.assertNoEvidence(lock)
+
+
+# ───────────────────────── the shared resolver ─────────────────────────
+
+
+class TestSharedResolver(unittest.TestCase):
+    def test_recovery_lock_resolves_to_recovery_evidence(self):
+        token = gitea_mcp_server._owning_pr_continuation_from_lock(recovery_lock())
+        self.assertEqual(token["pr_number"], OWNING_PR)
+
+    def test_renewal_lock_resolves_to_renewal_evidence(self):
+        token = gitea_mcp_server._owning_pr_continuation_from_lock(renewal_lock())
+        self.assertEqual(token["pr_number"], OWNING_PR)
+
+    def test_recovery_takes_precedence_over_renewal(self):
+        # Same precedence gitea_lock_issue applies when granting the waiver, so
+        # the answer cannot differ between the granting and enforcing paths.
+        lock = recovery_lock(pr_number=OTHER_PR, head=OTHER_HEAD)
+        lock["lease_renewal"] = renewal_record()
+        token = gitea_mcp_server._owning_pr_continuation_from_lock(lock)
+        self.assertEqual(token["pr_number"], OTHER_PR)
+
+    def test_no_evidence_resolves_to_none(self):
+        self.assertIsNone(gitea_mcp_server._owning_pr_continuation_from_lock(None))
+        self.assertIsNone(gitea_mcp_server._owning_pr_continuation_from_lock({}))
+        self.assertIsNone(
+            gitea_mcp_server._owning_pr_continuation_from_lock(
+                {"issue_number": ISSUE, "branch_name": BRANCH}
+            )
+        )
+
+
+# ────────────── every enforcement path uses the same decision ──────────────
+
+
+class TestEnforcementPathsShareOneDecision(unittest.TestCase):
+    """AC: commit, push and create-PR gates consume one authoritative token."""
+
+    def setUp(self):
+        self.token = gitea_mcp_server._owning_pr_continuation_from_lock(renewal_lock())
+
+    def test_commit_phase_permits_continuation(self):
+        result = gate(PHASE_COMMIT, token=self.token)
+        self.assertFalse(result["block"])
+        self.assertTrue(result["owning_pr_recovery_exempted"])
+        self.assertEqual(result["outcome"], OUTCOME_DUPLICATE_WORK_NOT_PREVENTED)
+
+    def test_create_pr_phase_permits_continuation(self):
+        result = gate(PHASE_CREATE_PR, token=self.token)
+        self.assertFalse(result["block"])
+        self.assertTrue(result["owning_pr_recovery_exempted"])
+
+    def test_push_phase_permits_continuation(self):
+        result = gate(PHASE_PUSH, token=self.token)
+        self.assertFalse(result["block"])
+        self.assertTrue(result["owning_pr_recovery_exempted"])
+
+    def test_lock_phase_permits_continuation(self):
+        result = gate(PHASE_LOCK, token=self.token)
+        self.assertFalse(result["block"])
+
+    def test_all_phases_agree(self):
+        outcomes = {
+            phase: gate(phase, token=self.token)["block"]
+            for phase in (PHASE_LOCK, PHASE_COMMIT, PHASE_PUSH, PHASE_CREATE_PR)
+        }
+        self.assertEqual(set(outcomes.values()), {False}, outcomes)
+
+    def test_dead_session_recovery_still_permits_continuation(self):
+        token = gitea_mcp_server._owning_pr_continuation_from_lock(recovery_lock())
+        for phase in (PHASE_COMMIT, PHASE_PUSH, PHASE_CREATE_PR):
+            with self.subTest(phase=phase):
+                result = gate(phase, token=token)
+                self.assertFalse(result["block"])
+                self.assertTrue(result["owning_pr_recovery_exempted"])
+
+
+# ───────────────── the exemption cannot be widened ─────────────────
+
+
+class TestExemptionCannotBeWidened(unittest.TestCase):
+    def setUp(self):
+        self.token = gitea_mcp_server._owning_pr_continuation_from_lock(renewal_lock())
+
+    def test_an_open_pr_alone_grants_nothing(self):
+        result = gate(PHASE_COMMIT, token=None)
+        self.assertTrue(result["block"])
+        self.assertFalse(result["owning_pr_recovery_exempted"])
+
+    def test_a_second_pr_is_refused(self):
+        result = gate(
+            PHASE_CREATE_PR,
+            token=self.token,
+            open_prs=[owning_pr(), owning_pr(number=OTHER_PR, ref=OTHER_BRANCH)],
+        )
+        self.assertTrue(result["block"])
+        self.assertFalse(result["owning_pr_recovery_exempted"])
+
+    def test_a_different_pr_is_refused(self):
+        result = gate(
+            PHASE_COMMIT, token=self.token, open_prs=[owning_pr(number=OTHER_PR)]
+        )
+        self.assertTrue(result["block"])
+
+    def test_a_different_branch_is_refused(self):
+        result = gate(
+            PHASE_COMMIT, token=self.token, open_prs=[owning_pr(ref=OTHER_BRANCH)]
+        )
+        self.assertTrue(result["block"])
+
+    def test_locked_branch_mismatch_is_refused(self):
+        result = gate(PHASE_COMMIT, token=self.token, locked_branch=OTHER_BRANCH)
+        self.assertTrue(result["block"])
+
+    def test_live_pr_head_divergence_is_refused(self):
+        # Force-push or unrelated remote movement after renewal.
+        result = gate(
+            PHASE_COMMIT, token=self.token, open_prs=[owning_pr(sha=OTHER_HEAD)]
+        )
+        self.assertTrue(result["block"])
+
+    def test_evidence_for_another_issue_is_refused(self):
+        foreign = gitea_mcp_server._owning_pr_continuation_from_lock(
+            renewal_lock(issue_number=ISSUE + 1)
+        )
+        result = gate(PHASE_COMMIT, token=foreign)
+        self.assertTrue(result["block"])
+
+    def test_sequential_tasks_do_not_inherit_continuation(self):
+        # One daemon serves many tasks. A renewal proved for issue N must not
+        # authorize continuation for the next task's issue.
+        prior_task = gitea_mcp_server._owning_pr_continuation_from_lock(
+            renewal_lock(issue_number=ISSUE + 7)
+        )
+        self.assertIsNotNone(prior_task)
+        self.assertTrue(gate(PHASE_COMMIT, token=prior_task)["block"])
+
+
+# ───────────────── ordinary duplicate prevention is intact ─────────────────
+
+
+class TestDuplicatePreventionRetained(unittest.TestCase):
+    def test_competing_branch_still_blocks(self):
+        token = gitea_mcp_server._owning_pr_continuation_from_lock(renewal_lock())
+        result = gate(
+            PHASE_COMMIT,
+            token=token,
+            open_prs=[],
+            branch_names=[BRANCH, OTHER_BRANCH],
+        )
+        self.assertTrue(result["block"])
+
+    def test_unrelated_work_without_a_lock_still_blocks(self):
+        token = gitea_mcp_server._owning_pr_continuation_from_lock(None)
+        self.assertIsNone(token)
+        self.assertTrue(gate(PHASE_COMMIT, token=token)["block"])
+
+
+# ───────────────── refusals stay structured and auditable ─────────────────
+
+
+class TestRefusalShapePreserved(unittest.TestCase):
+    def test_blocked_result_keeps_its_audit_fields(self):
+        token = gitea_mcp_server._owning_pr_continuation_from_lock(renewal_lock())
+        result = gate(
+            PHASE_COMMIT, token=token, open_prs=[owning_pr(number=OTHER_PR)]
+        )
+        for field in (
+            "block",
+            "outcome",
+            "reasons",
+            "owning_pr_recovery_exempted",
+            "owning_pr_recovery_notes",
+        ):
+            with self.subTest(field=field):
+                self.assertIn(field, result)
+        self.assertTrue(result["reasons"])
+        # A rejected token explains which element of ownership disagreed.
+        self.assertTrue(result["owning_pr_recovery_notes"])
+
+    def test_granted_result_records_why(self):
+        token = gitea_mcp_server._owning_pr_continuation_from_lock(renewal_lock())
+        result = gate(PHASE_COMMIT, token=token)
+        self.assertTrue(result["owning_pr_recovery_notes"])
+        self.assertIn(
+            f"#{OWNING_PR}", " ".join(result["owning_pr_recovery_notes"])
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()