fix(mcp): forward worktree_path into publication preflight (Closes #815)

gitea_publish_unpublished_issue_branch accepted a required worktree_path
but resolved it only after verify_preflight_purity had already run, so the
#618 branches-only guard and every other workspace-resolution layer behind
preflight received None and fell back to the MCP process root. A daemon
rooted at the stable control checkout therefore refused a valid registered
issue worktree the caller had explicitly supplied, before the publication
assessor could use it — the sole verify_preflight_purity call site that
accepted a worktree argument and dropped it.

Resolve the workspace once, before preflight, and forward it. A blank or
absent path forwards None and keeps the ordinary #618 fail-closed fallback,
so guard strictness is unchanged for missing, empty, unregistered, foreign,
or control-checkout worktrees. Public tool contract, ownership, cleanliness,
hash, ancestry, and read-after-write protections from PR #814 are untouched.

Adds tests/test_issue_815_preflight_worktree_forwarding.py: a #735-style
capture proving the argument reaches verify_preflight_purity, a faithful
production reproduction (control-rooted daemon, no session lock, explicit
worktree) that clears #618 on the fixed source and is trapped at #618 on the
unpatched source, an end-to-end control-rooted publication in the real
topology (PROJECT_ROOT is the stable control checkout, the issue worktree is
a distinct registered path, production guards forced on), and negative
coverage keeping every #618 and assessor refusal intact. The prior #812
suite masked the defect by patching PROJECT_ROOT to equal the issue worktree.

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

gitea_mcp_server.py

@@ -9173,11 +9173,27 @@ def gitea_publish_unpublished_issue_branch(
     if blocked:
         return blocked
 
-    verify_preflight_purity(remote, task=task, org=org, repo=repo)
+    # #815: resolve the caller's worktree *before* preflight and forward it, so
+    # every workspace-resolution layer behind verify_preflight_purity — including
+    # the #618 branches-only guard — judges the registered issue worktree this
+    # publication actually operates on. Resolving it afterwards let preflight
+    # fall back to the MCP process root, so a daemon rooted at the stable control
+    # checkout refused a valid explicit worktree before the assessor ever ran.
+    # A caller supplying nothing usable forwards None and keeps the ordinary
+    # fail-closed fallback.
+    explicit_worktree = (worktree_path or "").strip()
+    workspace = os.path.realpath(os.path.abspath(explicit_worktree or "."))
+
+    verify_preflight_purity(
+        remote,
+        worktree_path=workspace if explicit_worktree else None,
+        task=task,
+        org=org,
+        repo=repo,
+    )
 
     h, o, r = _resolve(remote, host, org, repo)
     git_remote = (git_remote_name or remote or "").strip()
-    workspace = os.path.realpath(os.path.abspath((worktree_path or "").strip() or "."))
 
     existing_lock = issue_lock_store.load_issue_lock(
         remote=remote, org=o, repo=r, issue_number=int(issue_number)

tests/test_issue_815_preflight_worktree_forwarding.py

@@ -0,0 +1,622 @@
+"""Publication preflight must receive the caller's worktree (#815).
+
+``gitea_publish_unpublished_issue_branch`` takes a **required** ``worktree_path``
+but resolved it only *after* ``verify_preflight_purity`` had already run. Every
+workspace-resolution layer behind that preflight — canonical root, root checkout,
+create-issue bootstrap, the #618 branches-only guard, issue scope, and anti-stomp
+— therefore received ``None`` and fell back to the MCP process root. A daemon
+rooted at the stable control checkout refused a valid registered issue worktree
+that the caller had explicitly supplied, before the publication assessor ever ran.
+
+The #812 suite could not see this. Its fixture sets ``self.worktree =
+os.path.realpath(self.repo)`` and patches ``PROJECT_ROOT`` to that same path, so
+the fallback resolved to the very worktree the argument named. The production
+topology — control checkout on a stable branch, issue worktree somewhere else —
+was never constructed, and preflight additionally no-ops under pytest unless
+production guards are forced on.
+
+These tests build that topology honestly:
+
+* ``PROJECT_ROOT`` is a control checkout sitting on ``master``;
+* the registered issue worktree is a genuinely separate path under ``branches/``;
+* ``GITEA_TEST_FORCE_PRODUCTION_GUARDS`` is set so the #618 guard really runs;
+* no patch makes the issue worktree appear to be ``PROJECT_ROOT``.
+
+Nothing here reads, writes, or references the protected worktree named in #812
+AC17 and #815 AC9. Every fixture is built from scratch against a local bare
+remote, so publication and read-after-write verification genuinely execute.
+"""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+from unittest.mock import patch
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
+import issue_lock_provenance  # noqa: E402
+import issue_lock_store  # noqa: E402
+import mcp_server  # noqa: E402
+from mutation_profile_fixture import shared_mutation_env  # noqa: E402
+
+ISSUE = 9815
+BRANCH = f"feat/issue-{ISSUE}-forwarding-fixture"
+WORKTREE_DIRNAME = BRANCH.replace("/", "-")
+IDENTITY = "example-user"
+PROFILE = "test-author-prgs"
+ORG = "Scaled-Tech-Consulting"
+REPO = "Gitea-Tools"
+GIT_REMOTE = "prgs"
+
+AUTHOR_PROFILE = {
+    "profile_name": "prgs-author",
+    "role": "author",
+    "allowed_operations": [
+        "gitea.read", "gitea.issue.create", "gitea.issue.comment",
+        "gitea.pr.create", "gitea.repo.commit", "gitea.branch.push",
+    ],
+    "forbidden_operations": [],
+    "audit_label": "prgs-author",
+}
+
+
+def _ts(hours: int) -> str:
+    return (
+        (datetime.now(timezone.utc) + timedelta(hours=hours))
+        .isoformat()
+        .replace("+00:00", "Z")
+    )
+
+
+class TestPreflightReceivesTheWorktree(unittest.TestCase):
+    """AC1 — the supplied path reaches ``verify_preflight_purity`` itself.
+
+    Follows the #735 capture pattern: replace preflight with a recorder that
+    raises, so the argument can be proven forwarded without performing the
+    mutation. This is the direct unit-level statement of the defect.
+    """
+
+    def _capture_preflight(self, **kwargs):
+        captured: dict = {}
+
+        def _capture(*a, **kw):
+            captured.update(kw)
+            captured["_args"] = a
+            raise RuntimeError("capture-only")
+
+        with patch.object(
+            mcp_server, "verify_preflight_purity", side_effect=_capture
+        ), patch.object(
+            mcp_server, "get_profile", return_value=AUTHOR_PROFILE
+        ), patch.object(
+            mcp_server, "_resolve",
+            return_value=("gitea.prgs.cc", ORG, REPO),
+        ), patch.object(
+            mcp_server, "_auth", return_value="token fake",
+        ), patch.object(
+            mcp_server.role_session_router,
+            "check_author_mutation_after_reviewer_stop",
+            return_value=(True, []),
+        ), patch.object(
+            mcp_server, "_namespace_mutation_block", return_value=None
+        ), patch.object(
+            mcp_server, "_profile_permission_block", return_value=None
+        ):
+            try:
+                mcp_server.gitea_publish_unpublished_issue_branch(**kwargs)
+            except RuntimeError as exc:
+                if "capture-only" not in str(exc) and not captured:
+                    raise
+        self.assertTrue(
+            captured,
+            "gitea_publish_unpublished_issue_branch never called "
+            "verify_preflight_purity",
+        )
+        return captured
+
+    def _base_kwargs(self, **overrides):
+        kwargs = {
+            "issue_number": ISSUE,
+            "branch_name": BRANCH,
+            "worktree_path": "/tmp/issue-815-explicit-worktree",
+            "expected_head": "a" * 40,
+            "remote": "prgs",
+            "org": ORG,
+            "repo": REPO,
+            "git_remote_name": GIT_REMOTE,
+        }
+        kwargs.update(overrides)
+        return kwargs
+
+    def test_explicit_worktree_path_reaches_preflight(self):
+        captured = self._capture_preflight(**self._base_kwargs())
+        self.assertEqual(
+            captured.get("worktree_path"),
+            os.path.realpath(os.path.abspath("/tmp/issue-815-explicit-worktree")),
+            "the authoritative worktree_path must be forwarded into preflight",
+        )
+
+    def test_forwarded_path_is_the_one_publication_uses(self):
+        """AC4 — preflight and publication must judge the same resolved path."""
+        raw = "/tmp/issue-815-explicit-worktree/./"
+        captured = self._capture_preflight(**self._base_kwargs(worktree_path=raw))
+        expected = os.path.realpath(os.path.abspath(raw.strip()))
+        self.assertEqual(captured.get("worktree_path"), expected)
+
+    def test_blank_worktree_path_forwards_none(self):
+        """AC5/AC8 — nothing usable supplied keeps the fail-closed fallback."""
+        for blank in ("", "   "):
+            with self.subTest(blank=repr(blank)):
+                captured = self._capture_preflight(
+                    **self._base_kwargs(worktree_path=blank)
+                )
+                self.assertIsNone(
+                    captured.get("worktree_path"),
+                    "a blank worktree must not resolve to the process cwd",
+                )
+
+    def test_org_repo_and_task_forwarding_are_not_regressed(self):
+        """AC6 — #735's org/repo forwarding and the task name still hold."""
+        captured = self._capture_preflight(**self._base_kwargs())
+        self.assertEqual(captured.get("org"), ORG)
+        self.assertEqual(captured.get("repo"), REPO)
+        self.assertEqual(captured.get("task"), "publish_unpublished_branch")
+
+
+class _ProductionTopologyBase(unittest.TestCase):
+    """Control checkout on master + a distinct registered issue worktree.
+
+    This is the shape the production daemon runs in and the shape the #812
+    fixture never built. ``PROJECT_ROOT`` is the control checkout; the issue
+    worktree is a real registered worktree at a different path; production
+    guards are forced on so the #618 branches-only guard genuinely evaluates.
+    """
+
+    def setUp(self):
+        self.lock_dir = tempfile.TemporaryDirectory()
+        self.addCleanup(self.lock_dir.cleanup)
+        self.origin = tempfile.mkdtemp(prefix="issue815-origin-")
+        self.control = tempfile.mkdtemp(prefix="issue815-control-")
+        for path in (self.origin, self.control):
+            self.addCleanup(
+                lambda p=path: subprocess.run(["rm", "-rf", p], check=False)
+            )
+        self._init_repos()
+        self.remotes = patch.dict(
+            mcp_server.REMOTES,
+            {"prgs": {"host": "gitea.prgs.cc", "org": ORG, "repo": REPO}},
+        )
+        self.remotes.start()
+        self.addCleanup(patch.stopall)
+        mcp_server._IDENTITY_CACHE.clear()
+
+    def _git(self, *args, cwd=None):
+        return subprocess.run(
+            ["git", "-C", cwd or self.control, *args],
+            capture_output=True, text=True, check=True,
+        )
+
+    def _init_repos(self):
+        subprocess.run(
+            ["git", "init", "-q", "--bare", "-b", "master", self.origin], check=True
+        )
+        self._git("init", "-q", "-b", "master")
+        self._git("config", "user.email", "[email protected]")
+        self._git("config", "user.name", "Test")
+        self._git("remote", "add", GIT_REMOTE, self.origin)
+
+        with open(os.path.join(self.control, "seed.txt"), "w") as fh:
+            fh.write("seed\n")
+        # The real repository gitignores branches/, so a registered worktree
+        # living there does not dirty the stable control checkout. Mirror that,
+        # or the #615 dirty-runtime block fires on the worktree we just created.
+        with open(os.path.join(self.control, ".gitignore"), "w") as fh:
+            fh.write("branches/\n")
+        self._git("add", "seed.txt", ".gitignore")
+        self._git("commit", "-q", "-m", "seed")
+        self.base_sha = self._git("rev-parse", "HEAD").stdout.strip()
+        self._git("push", "-q", GIT_REMOTE, "master")
+
+        # The control checkout STAYS on master. This is the whole point: the
+        # daemon's process root is the stable control checkout, never the
+        # worktree the publication targets.
+        self.worktree = os.path.realpath(
+            os.path.join(self.control, "branches", WORKTREE_DIRNAME)
+        )
+        self._git("worktree", "add", "-q", "-b", BRANCH, self.worktree, "master")
+
+        with open(os.path.join(self.worktree, "work.txt"), "w") as fh:
+            fh.write("unpublished implementation\n")
+        self._git("add", "work.txt", cwd=self.worktree)
+        self._git("commit", "-q", "-m", "unpublished implementation", cwd=self.worktree)
+        self.head_sha = self._git("rev-parse", "HEAD", cwd=self.worktree).stdout.strip()
+
+        self.control_branch = self._git(
+            "rev-parse", "--abbrev-ref", "HEAD"
+        ).stdout.strip()
+
+    # ── durable lock naming the caller and the issue worktree ────────────
+    def lock_path(self):
+        return issue_lock_store.lock_file_path(
+            remote="prgs", org=ORG, repo=REPO, issue_number=ISSUE,
+            lock_dir=self.lock_dir.name,
+        )
+
+    def write_lock(self, *, bind_session=True, **overrides):
+        path = self.lock_path()
+        claimant = overrides.pop(
+            "claimant", {"username": IDENTITY, "profile": PROFILE}
+        )
+        pid = overrides.pop("session_pid", os.getpid())
+        lease = {
+            "operation_type": issue_lock_store.AUTHOR_ISSUE_WORK_LEASE,
+            "issue_number": ISSUE,
+            "pr_number": None,
+            "branch": overrides.get("branch_name", BRANCH),
+            "worktree_path": overrides.get("worktree_path", self.worktree),
+            "claimant": claimant,
+            "created_at": _ts(-2),
+            "last_heartbeat_at": _ts(-2),
+            "expires_at": _ts(-1),
+        }
+        lease.update(overrides.pop("work_lease", {}))
+        data = {
+            "issue_number": ISSUE,
+            "branch_name": BRANCH,
+            "remote": "prgs",
+            "org": ORG,
+            "repo": REPO,
+            "worktree_path": self.worktree,
+            "session_pid": pid,
+            "pid": pid,
+            "lock_generation": 1,
+            "work_lease": lease,
+            "lock_provenance": issue_lock_provenance.build_sanctioned_lock_provenance(
+                tool="gitea_lock_issue", claimant=claimant
+            ),
+        }
+        data.update(overrides)
+        data["lock_file_path"] = path
+        issue_lock_store.save_lock_file(path, data)
+        # Bind the session pointer so the #683 issue-scope guard resolves an
+        # owning issue for this author session. In real production the publish
+        # task does not require a session lock — require_author_lock is keyed on
+        # the test-only production_guards_forced() flag, which this suite must
+        # set to make preflight run at all — so this pointer is fixture
+        # scaffolding to clear a guard production would not apply here, never a
+        # softening of the worktree-forwarding behaviour under test. The
+        # preflight-negative cases below leave it unbound precisely so the #618
+        # guard is reached with no session fallback to rescue a bad worktree.
+        if bind_session:
+            pointer = {
+                "pid": os.getpid(),
+                "lock_file_path": path,
+                "issue_number": ISSUE,
+                "branch_name": data["branch_name"],
+                "remote": "prgs",
+                "org": ORG,
+                "repo": REPO,
+            }
+            issue_lock_store.save_lock_file(
+                issue_lock_store.session_pointer_path(self.lock_dir.name), pointer
+            )
+        return path
+
+    def _tool_env(self):
+        env = shared_mutation_env(
+            PROFILE, include_example_repo=True,
+            GITEA_ISSUE_LOCK_DIR=self.lock_dir.name,
+        )
+        env["GITEA_ISSUE_LOCK_DIR"] = self.lock_dir.name
+        # The defect only exists where preflight actually runs. Under pytest the
+        # production root/branches/scope guards are skipped unless forced on, so
+        # force them: this test exists to exercise the #618 guard, not to bypass
+        # it. Parity is pinned to the server's own startup head so repointing
+        # PROJECT_ROOT does not read as a stale daemon.
+        env["GITEA_TEST_FORCE_PRODUCTION_GUARDS"] = "1"
+        # Production is a promoted stable-control runtime. The pytest process
+        # itself runs from a branches/ worktree, which the #615 runtime-mode
+        # gate correctly classifies as dev-test; declaring the sanctioned mode
+        # models the production daemon rather than defeating the gate. Without
+        # this, forcing production guards on would trip the *runtime-mode* block
+        # for a reason unrelated to the #815 worktree-forwarding defect.
+        env["GITEA_MCP_RUNTIME_MODE"] = "stable-control"
+        startup_head = mcp_server._STARTUP_PARITY.get("startup_head") or ""
+        env["GITEA_TEST_CURRENT_HEAD"] = startup_head
+        env["GITEA_TEST_LIVE_REMOTE_HEAD"] = startup_head
+        return env
+
+    def run_publish(self, *, open_prs=None, expected_head=None, **kwargs):
+        """Drive the public tool with PROJECT_ROOT pinned to the CONTROL checkout."""
+        env = self._tool_env()
+        with patch(
+            "mcp_server._list_open_pulls", return_value=list(open_prs or [])
+        ), patch(
+            "mcp_server._auth", return_value="token x"
+        ), patch(
+            "mcp_server.get_auth_header", return_value="token x"
+        ), patch(
+            "mcp_server._work_lease_claimant",
+            return_value={"username": IDENTITY, "profile": PROFILE},
+        ), patch.object(
+            # NOTE: the control checkout — deliberately NOT self.worktree.
+            mcp_server, "PROJECT_ROOT", self.control
+        ), patch.dict(os.environ, env, clear=True):
+            os.environ["GITEA_ISSUE_LOCK_DIR"] = self.lock_dir.name
+            return mcp_server.gitea_publish_unpublished_issue_branch(
+                issue_number=kwargs.pop("issue_number", ISSUE),
+                branch_name=kwargs.pop("branch_name", BRANCH),
+                worktree_path=kwargs.pop("worktree_path", self.worktree),
+                expected_head=expected_head or self.head_sha,
+                remote="prgs",
+                git_remote_name=kwargs.pop("git_remote_name", GIT_REMOTE),
+                **kwargs,
+            )
+
+    def remote_head(self, branch=BRANCH):
+        res = subprocess.run(
+            ["git", "-C", self.origin, "rev-parse", "--verify", "--quiet", branch],
+            capture_output=True, text=True, check=False,
+        )
+        return (res.stdout or "").strip() or None
+
+
+class TestForwardingClearsThe618Guard(_ProductionTopologyBase):
+    """AC2 — the faithful production reproduction, and the sharpest fix proof.
+
+    The production recovery worker had **no** session issue lock — acquiring one
+    was the very thing the deadlock prevented — so preflight had nothing but the
+    explicit ``worktree_path`` argument to resolve the workspace from. This class
+    reproduces exactly that: no session pointer is bound, so there is no
+    author-lock fallback to rescue a dropped argument.
+
+    With the argument forwarded (fixed source) the #618 branches-only guard
+    accepts the registered issue worktree and the call advances to the next
+    guard. With the argument dropped (the buggy source this issue reports)
+    preflight falls back to ``PROJECT_ROOT`` — the stable control checkout — and
+    the #618 guard traps the call there. The two outcomes are told apart by the
+    guard that fired, on its own error text.
+
+    This test therefore *fails* against the unpatched source (the call is trapped
+    at #618 instead of clearing it), which is what makes it a regression rather
+    than a smoke test.
+    """
+
+    _CONTROL_CHECKOUT_MARKERS = ("stable control checkout", "#618")
+
+    def test_explicit_worktree_clears_618_without_a_session_lock(self):
+        # No write_lock(): the session is deliberately unbound, as in production.
+        with self.assertRaises(RuntimeError) as ctx:
+            self.run_publish()
+        message = str(ctx.exception)
+        # The workspace guard is satisfied — the failure is the *later* scope
+        # guard (no owning issue), never the control-checkout refusal. If the
+        # argument were dropped, this call would be trapped at #618 instead.
+        for marker in self._CONTROL_CHECKOUT_MARKERS:
+            self.assertNotIn(
+                marker, message,
+                f"the explicit worktree must clear #618; got a control-checkout "
+                f"refusal instead: {message}",
+            )
+        self.assertIn(
+            "owning issue", message,
+            f"expected the downstream scope guard to fire, got: {message}",
+        )
+        self.assertIsNone(self.remote_head())
+
+    def test_dropped_argument_would_be_trapped_at_618(self):
+        # Simulate the buggy call shape directly: no session lock, and preflight
+        # given no worktree, exactly as the unpatched source left it. This pins
+        # the control-checkout refusal that the fix eliminates, so the pair of
+        # tests brackets the defect from both sides regardless of which source
+        # version is loaded.
+        env = self._tool_env()
+        with patch(
+            "mcp_server._list_open_pulls", return_value=[]
+        ), patch(
+            "mcp_server._auth", return_value="token x"
+        ), patch(
+            "mcp_server.get_auth_header", return_value="token x"
+        ), patch(
+            "mcp_server._work_lease_claimant",
+            return_value={"username": IDENTITY, "profile": PROFILE},
+        ), patch.object(
+            mcp_server, "PROJECT_ROOT", self.control
+        ), patch.dict(os.environ, env, clear=True):
+            os.environ["GITEA_ISSUE_LOCK_DIR"] = self.lock_dir.name
+            with self.assertRaises(RuntimeError) as ctx:
+                # Drive verify_preflight_purity the way the buggy body did:
+                # no worktree_path forwarded at all.
+                mcp_server.verify_preflight_purity(
+                    "prgs",
+                    task="publish_unpublished_branch",
+                    org=ORG,
+                    repo=REPO,
+                )
+        message = str(ctx.exception)
+        self.assertTrue(
+            any(m in message for m in self._CONTROL_CHECKOUT_MARKERS),
+            f"a dropped worktree must trap at the control checkout: {message}",
+        )
+        self.assertIsNone(self.remote_head())
+
+
+class TestProductionTopologyPublishes(_ProductionTopologyBase):
+    """AC2/AC4/AC7 — the explicit registered worktree is what preflight validates."""
+
+    def test_fixture_is_genuinely_the_production_topology(self):
+        """Guard the guard: if this drifts, the regression stops meaning anything."""
+        self.assertNotEqual(
+            os.path.realpath(self.control), self.worktree,
+            "the issue worktree must not be PROJECT_ROOT",
+        )
+        self.assertEqual(
+            self.control_branch, "master",
+            "the control checkout must sit on a stable branch",
+        )
+        self.assertTrue(
+            os.path.realpath(self.worktree).startswith(
+                os.path.realpath(os.path.join(self.control, "branches")) + os.sep
+            ),
+            "the issue worktree must live under branches/",
+        )
+        listed = subprocess.run(
+            ["git", "-C", self.control, "worktree", "list"],
+            capture_output=True, text=True, check=True,
+        ).stdout
+        self.assertIn(
+            self.worktree, listed, "the issue worktree must be genuinely registered"
+        )
+
+    def test_publishes_from_a_control_rooted_daemon(self):
+        """The exact production failure: this refused with #618 before the fix."""
+        self.write_lock()
+        self.assertIsNone(self.remote_head(), "fixture must start unpublished")
+        res = self.run_publish()
+        self.assertTrue(res.get("success"), res)
+        self.assertTrue(res.get("performed"), res)
+        self.assertEqual(self.remote_head(), self.head_sha)
+
+    def test_dry_run_uses_the_explicit_worktree(self):
+        """AC4 — dry-run reaches the same decision without publishing."""
+        self.write_lock()
+        res = self.run_publish(dry_run=True)
+        self.assertTrue(res.get("success"), res)
+        self.assertFalse(res.get("performed"), res)
+        self.assertTrue(res.get("would_publish"), res)
+        self.assertIsNone(self.remote_head(), "dry-run must not publish")
+
+    def test_dry_run_and_apply_agree_on_the_same_worktree(self):
+        """AC4 — both paths resolve the same workspace, so both succeed."""
+        self.write_lock()
+        dry = self.run_publish(dry_run=True)
+        self.assertTrue(dry.get("would_publish"), dry)
+        applied = self.run_publish()
+        self.assertTrue(applied.get("performed"), applied)
+        self.assertEqual(self.remote_head(), self.head_sha)
+
+    def test_read_after_write_verification_still_runs(self):
+        """AC6 — PR #814's post-publication verification is unchanged."""
+        self.write_lock()
+        res = self.run_publish()
+        self.assertTrue(res.get("verified"), res)
+        self.assertEqual(res.get("remote_head_sha"), self.head_sha)
+
+
+class TestProductionTopologyFailsClosed(_ProductionTopologyBase):
+    """AC3/AC5/AC8 — the fix does not weaken any refusal.
+
+    A refusal reaches the caller by one of two mechanisms, and this class holds
+    them apart deliberately. A bad *workspace* is caught by the #618 preflight
+    guard, which raises before the assessor is built. A bad *content/ownership*
+    fact passes preflight (the worktree itself is fine) and is then refused by
+    the publication assessor, which returns ``success: False``. Both are
+    fail-closed; asserting the wrong mechanism would hide a regression.
+    """
+
+    # ── #618 preflight refusals: no session lock, so nothing rescues a bad
+    #    workspace and the guard fires exactly as it does in production ──────
+    def _assert_preflight_raises(self, **kwargs):
+        with self.assertRaises(RuntimeError) as ctx:
+            self.run_publish(**kwargs)
+        self.assertIsNone(
+            self.remote_head(), "a blocked publication must not reach the remote"
+        )
+        return str(ctx.exception)
+
+    def test_blank_worktree_path_fails_closed_via_618(self):
+        """AC5 — a blank path forwards None, so preflight sees the control root."""
+        for blank in ("", "   "):
+            with self.subTest(blank=repr(blank)):
+                message = self._assert_preflight_raises(worktree_path=blank)
+                self.assertIn("618", message)
+
+    def test_control_checkout_as_worktree_fails_closed_via_618(self):
+        """AC5 — naming the stable control checkout explicitly is still refused."""
+        message = self._assert_preflight_raises(worktree_path=self.control)
+        self.assertIn("618", message)
+
+    def test_unregistered_directory_fails_closed(self):
+        """AC3 — a plain directory under branches/ is not a registered worktree."""
+        bogus = os.path.join(self.control, "branches", "not-a-worktree")
+        os.makedirs(bogus, exist_ok=True)
+        self._assert_preflight_raises(worktree_path=bogus)
+
+    def test_missing_worktree_path_fails_closed(self):
+        """AC3 — a path that does not exist is refused, not silently replaced."""
+        missing = os.path.join(self.control, "branches", "absent-worktree")
+        self._assert_preflight_raises(worktree_path=missing)
+
+    # ── assessor refusals: preflight passes on a valid worktree, then the
+    #    publication assessor refuses on content/ownership evidence ──────────
+    def _assert_assessor_refuses(self, **kwargs):
+        res = self.run_publish(**kwargs)
+        self.assertFalse(res.get("success"), res)
+        self.assertFalse(res.get("performed"), res)
+        self.assertIsNone(self.remote_head())
+        return res
+
+    def test_changed_local_head_still_refuses(self):
+        """AC6 — the declared expected_head remains authoritative."""
+        self.write_lock()
+        self._assert_assessor_refuses(expected_head="b" * 40)
+
+    def test_foreign_claimant_still_refuses(self):
+        """AC6 — ownership still comes from the durable lock record."""
+        self.write_lock(claimant={"username": "someone-else", "profile": PROFILE})
+        self._assert_assessor_refuses()
+
+    def test_dirty_worktree_still_refuses(self):
+        """AC6 — cleanliness enforcement survives the forwarding change."""
+        self.write_lock()
+        with open(os.path.join(self.worktree, "work.txt"), "a") as fh:
+            fh.write("uncommitted drift\n")
+        self._assert_assessor_refuses()
+
+    def test_competing_open_pr_still_refuses(self):
+        """AC6 — a rival claim on another branch still blocks."""
+        self.write_lock()
+        self._assert_assessor_refuses(
+            open_prs=[{"number": 4242, "head": {"ref": f"fix/issue-{ISSUE}-rival"}}]
+        )
+
+    def test_issue_lock_record_is_not_mutated_by_a_refusal(self):
+        """AC6 — record separation (#812 AC23) is unaffected by this change."""
+        path = self.write_lock()
+        with open(path, "rb") as fh:
+            before = fh.read()
+        self._assert_assessor_refuses(expected_head="c" * 40)
+        with open(path, "rb") as fh:
+            self.assertEqual(before, fh.read())
+
+
+class TestProtectedFixtureNotReferenced(unittest.TestCase):
+    """AC9 — this regression never names the protected #635 fixture.
+
+    The forbidden tokens are reconstructed from fragments so this assertion
+    file does not itself contain them and produce a false positive.
+    """
+
+    def test_no_reference_to_the_protected_worktree(self):
+        forbidden = [
+            "issue-635-" + "project-registry-api",
+            "b2f6e9a6dc40e9651ef8" + "76f322dd0a68bddebfd8",
+        ]
+        here = os.path.abspath(__file__)
+        with open(here, "r", encoding="utf-8") as fh:
+            text = fh.read()
+        for token in forbidden:
+            self.assertNotIn(
+                token, text,
+                f"the protected #635 fixture must not be referenced: {token}",
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()