Gate-2 fallout chain: session 1's bare-id wedge poisoned ACE's save (the
client reported garbage cells while walking through walls), so session 2
logged in with (cell=0xA9B4013F inn interior, pos=(91.4,32.7)) — a
position that cell does not contain. Probe evidence: exactly one
[cell-transit] line all session; the player free-fell into an empty
world. Two holes, both fixed at the root:
1. CellTransit pick escape hatch — restores the #83/A1.7 + #90
verification that lived in PhysicsEngine.ResolveCellId before the
collide-then-pick rewrite moved membership into
BuildCellSetAndPickContaining: an indoor current cell that IS
hydrated but whose CellBSP no longer overlaps ANY part of the foot
sphere is a bogus claim (corrupt save, or walked out through an
unblocked gap). The portal BFS can never reach an exit portal from a
cell the sphere isn't in, so no candidates exist and the claim held
forever — wedging collision (ShadowObjectRegistry's #98 gate reads
"indoor primary" -> outdoor object sweep skipped), wall BSP, terrain,
and the render root. The pick now demotes to the outdoor column under
the sphere centre (the LandDefs.AdjustToOutside result already
computed for the pick — cross-block safe). Sphere-overlap
(BSPQuery.SphereIntersectsCellBsp, pseudo_c:317666 -> :323267), NOT
point-in: doorway push-back leaves the centre a few cm outside while
the sphere still overlaps — no demotion, #90's ping-pong stays dead.
An unhydrated cell cannot be verified — stale beats null while
streaming hydrates (retail-equivalent: stale curr_cell kept when the
pick finds nothing).
2. PlayerModeAutoEntry spawn-ground hold — player-mode entry now waits
for the terrain under the spawn position to stream in
(isSpawnGroundReady predicate, K.2 pattern). Entering earlier
integrates gravity against an empty world: indoor-claimed spawns got
no floor from any source and free-fell into the void; outdoor spawns
raced hydration by ~1s every login. Retail never has this state (it
loads cells synchronously) — the hold is the async-streaming
equivalent of that invariant. With the hold, the entry snap
(Resolve, stepUp=100) runs against hydrated cell floors + terrain
and re-seats a corrupt save's claim immediately.
Tests: IndoorSeed_SphereFullyOutsideHydratedCell_DemotesToOutdoorColumn
(the gate-2 wedge shape, red pre-fix), straddle + no-BSP guards (the #90
hysteresis and stale-beats-null), TryEnter_Armed_SpawnGroundNotReady_
DoesNotFire. Full suite: 294+218+420 green; Core 1375 green + the same
4 pre-existing door/#99-era failures + 1 skip.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>