Retail re-cells children when their parent crosses a cell, recursively, to
unbounded depth. acdream did it from a RENDER tick, so headless parented
children were cell-less forever and the canonical cell had two writers. This
slice makes Runtime the sole authority and demotes App's tick to
presentation-only. Contract:
docs/research/2026-08-04-c4-route-7-contract.md; the research that unblocked
it is docs/research/2026-08-04-retail-parent-cell-propagation.md (ca96ea5e).
Retail: SetPositionInternal @0x00515330 branches on `this->cell == curr_cell`
@0x0051536d; the changed branch reaches change_cell @0x00513390, whose
delegates leave_cell @0x00510f50 and enter_cell @0x00510ed0 self-recurse over
children and write the FULL identity (add_object @0x00510ee2, objcell_id
@0x00510f1e, part-array cell id @0x00510f2b, cell pointer @0x00510f35).
change_cell itself has no child loop.
THE TRAP, recorded because it nearly shipped: the depth-1 loop
@0x0051539c-0x005153d8 is the SAME-CELL fast path (objcell_id and part-array
id only, deliberately not the cell pointer), NOT the propagation. An
implementer who finds it first concludes "depth-1, id-only" and strands every
equipped item at a landblock boundary — the #184 class. The clincher against
that reading: update_object @0x00515d10 early-returns on `parent != 0`
@0x00515d40, so a child never runs its own physics tick and parent
propagation is the ONLY mechanism maintaining its cell.
Route 7 performs NO placement (DoPickupEvent @0x00452240 = unset_parent +
leave_world; DoParentEvent @0x00452290 = set_parent + SetPlacementFrame), so
it arms ConstrainTo nowhere — the leash rule INVERTS relative to routes
2/4/5, and both reviewers confirmed nothing arms.
Propagation is an ITERATIVE WORKLIST, not recursion. The first implementation
recursed with a depth-64 cap; both reviews independently found the cap left a
truncated tail at a stale NON-ZERO cell — permanently unrecoverable, logged
only under a probe flag, and on the withdraw path exactly the #184 shape
AP-142 clause (a) exists to reject. Shipping a fresh #184 instance inside the
slice that fixes stranded children was not acceptable, so the cap was removed
rather than tuned. The worklist retires the cap, the constant, its register
clause, and the failure mode together. Termination: every record on the stack
is already at the target pair, so nothing can be pushed twice and a hostile
A->B->A cycle collapses without a visited set.
The child write deliberately bypasses the public RuntimeEntityDirectory
.SetFullCell and calls the record method directly. This is LOAD-BEARING:
the public method re-enters PropagateFullCellToChildren, which opens with
_propagationWorklist.Clear() — routing children through it mid-drain would
wipe the shared stack and silently drop every unprocessed sibling. Any future
side effect added to the public SetFullCell must be mirrored by hand at that
call site.
Deliberate divergence, recorded not disguised: retail's removal path leaves
children with a null cell pointer but a STALE nonzero objcell_id @0x005133c1.
acdream does not reproduce it, because FullCellId != 0 is the liveness
predicate at 45+ sites — faithful porting would mark dead children live.
AP-142 records this; clause (d) records that acdream cannot gate propagation
on HasPartArray the way enter_cell gates on part_array @0x00510ed8, because
the flag's only writers are graphical and headless never sets it — the reason
is Slice J LAYERING, not a semantic difference (retail's part_array is itself
a mesh-construction product, single assignment site makeAnimObject
@0x0050e930 -> CPartArray::CreateSetup @0x0050e93e).
D7 adopts retail's unset_parent-before-leave_world order @0x0045227f ->
@0x00452286, applied to BOTH pickup paths including the dormant executor
replay. Its inertness was verified by reverting it and finding all 12
propagation tests still green — reported honestly rather than papered over
with a manufactured test, and independently confirmed by both reviewers.
ClassifyLeaveWorld and its request/cause types are DELETED: retail has no
classification here, and method-per-cause IS the retail dispatch shape.
Wiring it would have forced a vacuous teleport-sequence predicate with the
#307 shape.
Two review rounds plus a coordinator-required third pass; 5 MAJORs. One was a
handoff failure worth recording: enter_cell's part_array guard was correctly
identified as load-bearing by the research, dropped by the contract when it
enumerated the writes, and inherited as an omission by the code — a right
finding that evaporated across two handoffs with nobody re-reading the source.
Another was a test that survived deleting the entire behaviour it claimed to
pin, because its assertion read a field written unconditionally one line
earlier.
NoProjection is structurally unreachable from TickChild (TryResolveExactAttachment
performs a strictly stronger form of the same guard one call earlier). Kept as
a fail-safe, unit-tested directly, and documented in two places rather than
wrapped in a fabricated end-to-end test.
Headless regression test — the direct gate for this defect, which FAILED
before this work because no code path existed:
RuntimeLiveEntitySessionControllerTests
.DirectSink_D5_StandaloneParentEventCommitsChildToParentsExactCell.
Probe: ACDREAM_PROBE_CHILD_CELL=1 emits [child-cell] lines at all four write
sites (attach / headless-attach / propagate / withdraw / delete). TEMPORARY.
Complete Release suite MEASURED at 11,079 passed / 4 skipped / 0 failed
(baseline 11,063 at cff52c44, +16). An allocation flake appeared once under
load and was proven NOT this slice by reachability — RuntimeCollisionReportingState
contains zero SetFullCell and zero ParentAttachments references.
STILL OWED: the two-client connected gate (equip/unequip, carry across
landblock boundaries, pickup, loot, reconnect) with ACDREAM_PROBE_CHILD_CELL=1,
and a session counts only if [child-cell] cause=propagate lines appear.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Routes the classifier's two NO-PLACEMENT remote branches — Interpolate
(contact, PlayerDistance < 96 m) and NoPositionOperation (no contact) — through
a Runtime-owned seam, and fixes the two divergences they carried. Teleport,
far-snap and cell-less stay on the legacy App path; 4b owns them.
Route 4 was split into 4a/4b after scoping put the whole route at 1,500-2,500
lines against a ~400 budget. 4a's branches perform no SetPosition, so this slice
carries no deferred-cell park, no service-window guard and no allocation
exposure — which is what made the split worth doing.
Divergences fixed, both previously unfiled:
* D1 — the NPC airborne branch hard-snapped Body.Position/Orientation and
branched on the client-tracked rmState.Airborne, never consulting the wire
IsGrounded bit. Retail's MoveOrTeleport @0x00516330 returns 0 at 0x0051636D
and writes nothing. Player remotes were already correct; NPCs were not.
* D2 — ConstrainTo was armed before the operation, unconditionally, so it fired
on the airborne no-op retail skips and anchored to the PRE-move position.
Retail arms it at 0x00454272, only when MoveOrTeleport returns nonzero,
anchored to &arg2->m_position read live, i.e. post-move.
AP-87 and TS-44 were carried deliberately, not delegated away. AP-87's three
conditions — including firstUp, which one round silently dropped — are preserved
as an explicit acdream policy layer applied AFTER the classifier commits to
Interpolate; the two previously separate player/NPC copies are now one. TS-44
stays an NPC-only caller gate; extending sticky suppression to player remotes has
no retail basis and no live evidence, so it was declined rather than absorbed.
Landing is explicitly carved out of 4a's ownership on both arms. A landing packet
classifies Interpolate, so an ordering slip would ENQUEUE a body that must PLANT
and a creature knocked off a ledge would glide down over a packet interval. The
carve-out is a named entry point returning AirborneSnap/SteadyStateInterpolate/
Legacy precisely so the PRECEDENCE is observable and testable rather than implied
by statement order — that is how the slip happened once and was caught.
The player/NPC asymmetry on landing is real and NOT resolved here: retail draws
no such distinction, but converging them is a behaviour decision needing its own
evidence. Filed into the 4b plan.
Register: AP-135 filed for the two bookkeeping writes the airborne branch
deliberately retains (rmState.CellId, LastServerPos/Time) — not retail's model,
but load-bearing for our catch-up sweep and staleness timer, and verified not to
be a canonical cell commit for ordinary remotes. AP-87 and TS-44 rewritten to
describe the code.
Honest remainder: App still owns branch selection, the airborne return, the cell
write, the entity write and the shadow publish, and headless satisfies "both
hosts drive the identical entry point" only vacuously since it returns early for
remotes. That is written into the 4b bullet rather than left implicit.
Cost: 364 non-comment production lines, 91% of the ~400 budget — the split did
isolate the cheap half, but not by much. Do not carry "well under" into 4b's
scoping.
Gates: complete Release solution 10,938 passed / 4 skipped / 0 failed (pre-4a
baseline 10,909). Four review rounds; the first three each introduced a new
behavioural defect while fixing another, and each left a comment asserting
behaviour that no longer matched — the final round's precedence matrix was
traced cell-by-cell against HEAD with only the D1-intended difference. App tests
call production entry points against a real WorldEntity and real classifier
output, closing route 2's #292 gap rather than repeating it.
Connected acceptance NOT run — needs a live second character.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Cutover slice C3-1 (the C3 flip's Runtime prerequisite, landed separately
after the flip itself was halted with structural findings — see the plan's
C3a/b/c decomposition). Hosts can now read the executor-completion facts
they must bind at cutover through one public, generation-gated channel
accessor: RuntimePlacementProjectionChannel.TryGetInitialCreateCompletion
returns RuntimeInitialCreatePlacementCompletion — the teleport-hook phase,
resident cell, replay outcomes, and per-Position route facts (disposition,
constrain phase, hook phase, stop-interpolation/zero-velocity/preserve-
heading/send-position flags) via public 1:1 mirror enums of the internal
classifier vocabulary. The projection is built once at completion, cached
in the same reaped entry as the internal receipt (identical acknowledge/
discard/clear lifecycle, ledger-covered), and read allocation-free.
Mirror maps enumerate every value explicitly with throwing catch-alls,
guarded by a sabotage-verified arity/round-trip reflection test. Doc
comments pin the two consumption rules: unparent/placement-frame are
already applied to the canonical snapshot (hosts must not re-apply), and
array order — not Sequence — is the authoritative Position-fact ordering.
Reviewed: architecture PASS + retail-conformance PASS (mirrors verified
member-for-member against the retail phase semantics; the route-fact
selection confirmed to cover exactly the host-bindable deferrals).
Runtime 932/932; complete Release solution 10,727 passed / 4 skips.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Cutover slice C0 (docs/plans/2026-08-02-placement-cutover.md): the seam
work that lets C3 flip hosts onto a complete receipt stream instead of
growing one mid-cutover. The executor's Released exit now publishes an
acknowledge-only ExecutorCompleted receipt through the one placement
projection stream — registered before observer dispatch, correlated to
the full execution receipt, reaped exactly once on acknowledgement/
discard/session-clear, and counted in the convergence ledger. All three
production placement sinks acknowledge-and-ignore the new kind via early
returns proven behavior-preserving for every existing kind; without them
the first such receipt at cutover would permanently wedge the exact-head
FIFO behind sinks that return false. Provably inert today: the publisher
has no production caller.
Execute's live inputs now derive from Runtime's own owners bound at
GameRuntime construction: UsePositionFromServer is retail's exact
autonomy_level != 2 (CommandInterpreter::UsePositionFromServer
0x006B3B40, startup-only knob), and PlayerDistance uses the live movement
controller's position with a null-safe fallback to the caller struct —
never a fabricated origin. TryPrepareAndSubmitAuthoredPlacement chains
the prepared-collision Setup read through PrepareMover to submission with
zero validation-semantics changes. TryCommitParent and CommitWithdrawal
gain the sibling cancellation flow (residence + ordinary placement
family); TryCommitParent deliberately omits LeaveWorld — retail's
set_parent performs its single gated leave_world (0x00515A90) and a
second would have no counterpart.
Not fully dormant: the two cancellation fixes change Runtime paths
production already calls (today as no-op-adjacent hardening, since
nothing upstream begins a residence yet); everything else is reachable
only by tests. Reviewed: retail-conformance PASS + architecture/
adversarial PASS after one fix round (sink wedge, completion-receipt
lifecycle, null-controller distance). Runtime 921/921; complete Release
solution 10,716 passed / 4 intentional skips.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The admission checkpoint (30012361) sealed accepted updates behind a
pending initial placement; nothing could apply them, so AcknowledgeAdoption
refused any non-empty FIFO and the residence system had no path to
completion. RuntimeInitialCreateContinuationExecutor is that missing
mechanism: a synchronous, retry-idempotent Execute transaction that adopts
the acknowledged initial placement exactly once (consuming the retained
completion so later authored placements for the key can begin), emits the
AfterEnterWorld hook request for the local player, replays deferred
missing-parent raw Creates and queued parent relations by parent GUID
(retail ProcessObjectNetBlobs order: whole-bucket detach, FIFO dispatch,
cancellation-aware restore), and drains the mixed continuation FIFO
strictly by sequence with retail route decisions taken at execution time
via ClassifyAcceptedPosition on live inputs (server-asserted wire contact,
data-driven animation proxy, live distance/options).
Apply bodies are shared with the legacy fused paths through new gate-less
instance seams on InboundPhysicsStateController that keep the one snapshot
store in lockstep; SameIncarnationCreate envelopes apply atomically with
per-stage idempotency and buffered publication after the final stage;
every abandonment path retires the residence through the lifetime choke
point and converges the ownership ledger (executor progress, deferred
buckets, replay windows, placement watches all folded into IsConverged).
Position/placement side effects are exactly-once under retry, external
mutations are detected via a field-masked executor baseline, and
AwaitingContinuationPlacement yields keep the FIFO head retryable.
Production routes are deliberately untouched: graphical and headless
Create still use legacy RegisterEntity, and no host calls Execute. The
cutover is the next checkpoint; AP-1/AD-1 remain open until it lands.
Register rows AD-59/AD-60/AP-130/AP-131/AP-132/TS-62/TS-63 document the
slice's deviations in this commit.
Reviewed: retail-conformance PASS + architecture/adversarial PASS after
five implementation rounds (wire-contact source, snapshot lockstep,
WeenieDescription merge, abandonment convergence, reentrant retirement
windows, acknowledged-completion leak, baseline precision, replay
containment/restore, queue-by-parent-GUID relation deferral all fixed at
root cause). Runtime tests 903/903; complete Release solution 10,696
passed / 4 intentional skips; focused executor gate 161/161.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Erik