fix(signals): a held staging beats an inherited verdict posture (#4544)

.changeset/fix-4544-own-probe.md

@@ -0,0 +1,5 @@
+---
+"@solidjs/signals": patch
+---
+
+A memo holding a transition's staging keeps that staging when its own pass probes, so the branch the hold opened does not wait on the signed-out world (#4544).

.changeset/fix-4544-own-staging.md

@@ -0,0 +1,5 @@
+---
+"@solidjs/signals": patch
+---
+
+A memo that already holds a transition's staging stays that transition's work when an inherited verdict posture would have pulled it out (#4544).

packages/signals/docs/RULES-DERIVED.md

@@ -206,7 +206,7 @@ An armed boundary catches a lane the same way it catches a transition (D-12, D-1
 
 What is rendered from a display-ahead read reveals together with it: an async memo over `latest(x)` holds the `latest` view's reveal until it lands; a combined `isPending(() => [fast(), copy()])` over two async memos, one wrapped in a sync memo, stays `true` until both land, because a memo's value is one shared slot — it computes under its own hold posture, never under the posture of whichever reader pulled it. A node whose fetch a hold is waiting on is that hold's work, not a verdict reader: a pass that re-runs it while its fetch is in flight reads plainly — following the change it is fetching for — even if an earlier pass of it called `isPending` or `latest` (#3884). A memo's posture is what it reads: one that reads a verdict reader's value is a derivation of a display-ahead read, and a verdict reader itself — `createMemo(() => [held(), V()])` with `V = createMemo(() => isPending(x) && latest(e))` shows `V`'s verdict now, beside the screen's `held()`, as the inline probe and a render effect reading both do (#4050: a Provider's children memo over a router shell). **The probe decides the pass's posture in either read order (clarified 2026-10-28):** a pass that probes is a verdict reader whether the probe came before or after a plain read of the same held node — `[x(), isPending(x)]` and `[isPending(x), x()]` both show `[committed, true]` now and re-derive at the landing (A10) — unless the pass is the hold's own work: born in its world (D-27, #4341) or re-run by the write it holds (#3884 above). Those two read plainly; a probe does not rescue them. A pass that read two holds' display-ahead values is one reveal unit of both (A15 lanes corollary, #3335): it waits for either lane's flight, never showing one hold's `latest()` beside a half-computed derivation of the other's.
 
-**A verdict posture outlives the pass that asked (ruled 2026-10-28):** a pass that asked (`isPending`, `latest`) is the hold's verdict reader on every later run of its node until one completes having asked nothing — that run still reads as a verdict reader; the next is an ordinary derivation. On each such run its plain read of a node the hold holds is the screen's (a frame reader, A10; re-derived at the landing as A15's stale reader) and it joins nothing, whoever dirtied it — a sync write, a boundary redraw, a landing. The hold's own work is not in this: a node whose fetch the hold waits on, or a pass born in its world, reads plainly whatever it asked before (the #3884 clause and D-27 #4341 above, unchanged). A boundary's display-ahead swap is this posture handed on: an `on` pass that read `latest`/`isPending` is a verdict reader, and the fallback swap it asks for runs as that reader's work — the output's pass reads nothing of the held frame (a pending tree is linked, not read) and its answer, the fallback, is shown now beside the held frame and stays the screen until the landing, instead of being staged with the write's frame as a plain `on`'s swap is (D-15): `[A] → [A + spinner] → [B + spinner] → [B + comments]`, never `[A] → [B + spinner]`. Only the `on` pass's asking counts: `latest()` inside the fallback is the fallback's own display-ahead, not the swap's — a plain `on` over an action-held input lands the swap with the frame whatever the fallback reads (#4337). Today two memories carry this — `CONFIG_VERDICT` left on the node by the pass that probed, and the node's listing in the hold's verdict lane (`fallback`'s `b._lane`, `recompute`'s head) — and the rule is the posture, not the membership. Pins: `tests/loading-on-rearm-3540.test.ts`, `tests/loading-on-frame-following-3540.test.ts` §4–5, `tests/loading-on-latest-fallback-4337.test.ts`.
+**A verdict posture outlives the pass that asked (ruled 2026-10-28):** a pass that asked (`isPending`, `latest`) is the hold's verdict reader on every later run of its node until one completes having asked nothing — that run still reads as a verdict reader; the next is an ordinary derivation. On each such run its plain read of a node the hold holds is the screen's (a frame reader, A10; re-derived at the landing as A15's stale reader) and it joins nothing, whoever dirtied it — a sync write, a boundary redraw, a landing. The hold's own work is not in this: a node whose fetch the hold waits on, or a pass born in its world, reads plainly whatever it asked before (the #3884 clause and D-27 #4341 above, unchanged). A boundary's display-ahead swap is this posture handed on: an `on` pass that read `latest`/`isPending` is a verdict reader, and the fallback swap it asks for runs as that reader's work — the output's pass reads nothing of the held frame (a pending tree is linked, not read) and its answer, the fallback, is shown now beside the held frame and stays the screen until the landing, instead of being staged with the write's frame as a plain `on`'s swap is (D-15): `[A] → [A + spinner] → [B + spinner] → [B + comments]`, never `[A] → [B + spinner]`. Only the `on` pass's asking counts: `latest()` inside the fallback is the fallback's own display-ahead, not the swap's — a plain `on` over an action-held input lands the swap with the frame whatever the fallback reads (#4337). Today two memories carry this — `CONFIG_VERDICT` left on the node by the pass that probed, and the node's listing in the hold's verdict lane (`fallback`'s `b._lane`, `recompute`'s head) — and the rule is the posture, not the membership. Pins: `tests/loading-on-rearm-3540.test.ts`, `tests/loading-on-frame-following-3540.test.ts` §4–5, `tests/loading-on-latest-fallback-4337.test.ts`. A node holding its own staging of a hold is that hold's work, and an inherited posture does not pull it out (2026-11-01, #4544).
 
 **Collapses:** [A31](./SPEC-ASYNC-SEMANTICS.md#a31-a-memo-computes-under-its-own-lane-posture-never-its-pullers) (#3442), §20.1 question 3 ("Yeah definitely it is held. Consistent with any optimistic update"), OL-R24/R25/R34, recovery 6.2. **Status:** standing. A memo over a verdict memo: `tests/verdict-memo-under-held-memo-4050.test.ts`, `packages/web/test/held-shell-pending-feedback-4050.spec.tsx` (U-10). **Fixed 2026-11-01:** the verdict shortcut in `propagateStatus` (a probed source settling re-derives its verdict reader) now clears the settled source from the reader's pending sources — left in place, an errored probe target stranded a reader re-parked on a second source at that source's landing; `tests/verdict-shortcut-pending-source-liveness.test.ts`.
 

packages/signals/docs/RULES-INDEX.md

@@ -54,7 +54,7 @@ Status legend: **live** stated and standing · **ruled** carries an explicit rul
 | A7 | amended | `docs/SPEC-ASYNC-SEMANTICS.md:167` | seat.ts×1 truth.ts×1 verdict.ts×1 | fuzz-findings-l2.test.ts×1 latest-uninitialized-over-latest-4362.test.ts×2 spec-async-semantics.test.ts×2 visibility-oracle-store.states.ts×1 visibility-oracle.states.ts×1 visibility-oracle.test.ts×1 | [ruled, amended in place] Resolved async never reads `[false, undefined]` — After an async memo resolves, `[isPending(x), latest(x)]` is `[false, resolvedValue]` — never `[false, undefined]`. **Amende… |
 | A8 | amended | `docs/SPEC-ASYNC-SEMANTICS.md:175` | — | create-deferred-3710.test.ts×1 createMemo.test.ts×1 visibility-oracle-store.states.ts×1 visibility-oracle.states.ts×2 | [ruled, amended in place 2026-07-07] `isPending(() => latest(x))` follows `x`'s own async only — verdicts are per-channel — (**re-ruled 2026-07-07c** — was "tracks the transition the same as `isPendin… |
 | A9 | amended | `docs/SPEC-ASYNC-SEMANTICS.md:183` | async.ts×1 projection.ts×1 target.ts×1 | spec-async-semantics.test.ts×3 visibility-oracle-store.states.ts×4 visibility-oracle-store.test.ts×1 | [ruled, amended in place 2026-07-07] Store leaves behind a firewall report the firewall's new-question refetch — `isPending` on a store leaf behind a firewall reports the firewall's refetch like any a… |
-| A10 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:191` | async.ts×1 core.ts×3 lanes.ts×1 scheduler.ts×1 seat.ts×1 verdict.ts×3 | boundary-not-born-held-3540.test.ts×1 createMemo.test.ts×1 error-staged-recovery.test.ts×1 fuzz-findings-l2.test.ts×1 ispending-memo-unstamped-hold-3457.test.ts×2 latest-isPending-consistency.test.ts×3 latest-uninitialized-over-latest-4362.test.ts×1 verdict-contract.test.ts×2 verdict-memo-flight-no-reask.test.ts×1 | [ruled] `[isPending(x), x()]` is atomic within one scope — `[isPending(x), x()]` read in one scope is atomic: a reader that observed the fresh value must not see `pending === true` for it. |
+| A10 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:191` | async.ts×1 core.ts×5 lanes.ts×1 scheduler.ts×1 seat.ts×1 verdict.ts×6 | boundary-not-born-held-3540.test.ts×1 createMemo.test.ts×1 error-staged-recovery.test.ts×1 fuzz-findings-l2.test.ts×1 ispending-memo-unstamped-hold-3457.test.ts×2 latest-isPending-consistency.test.ts×3 latest-uninitialized-over-latest-4362.test.ts×1 verdict-contract.test.ts×2 verdict-memo-flight-no-reask.test.ts×1 verdict-memo-held-branch-4544.test.ts×1 | [ruled] `[isPending(x), x()]` is atomic within one scope — `[isPending(x), x()]` read in one scope is atomic: a reader that observed the fresh value must not see `pending === true` for it. |
 | A11 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:103` | — | latest-isPending-consistency.test.ts×1 loading-fallback-in-flush-3540.test.ts×2 visibility-oracle-store.states.ts×2 visibility-oracle.states.ts×1 | [ruled] Sync derivations of held sources are visible through `latest()`/`isPending()` — Sync derivations of transition-held sources are visible through `latest()`/`isPending()` (held sync recompute is… |
 | A12 | amended | `docs/SPEC-ASYNC-SEMANTICS.md:199` | — | createOptimistic.test.ts×2 spec-async-semantics.test.ts×1 | [ruled, amended in place] Resting optimistic nodes report pending like a plain memo — A resting optimistic node reports pending via exactly the causes a plain async memo does (A19) — a reverting optim… |
 | A13 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:207` | — | spec-async-semantics.test.ts×7 | [ruled 2026-07-06 (promoted from B1)] Resting optimistic ≡ plain async memo at every checkpoint — (was B1) A resting optimistic node (no active override) is observationally identical to a plain async … |
@@ -75,7 +75,7 @@ Status legend: **live** stated and standing · **ruled** carries an explicit rul
 | A28 | ruled, mechanism landed | `docs/SPEC-ASYNC-SEMANTICS.md:95` | constants.ts×1 core.ts×12 lanes.ts×2 scheduler.ts×3 seat.ts×3 types.ts×1 verdict.ts×2 store.ts×5 | continuation-sibling-reader-4146.test.ts×1 createOptimistic.test.ts×5 fuzz-findings-l2.test.ts×6 held-derivation-not-a-proposal-3612.test.ts×1 issue-3800-repro.test.ts×1 latest-held-till-flush.test.ts×1 latest-memo-inline-parity.test.ts×1 posture-store-parity.test.ts×5 question-scoped-pending.test.ts×3 snapshot-derived-store-rows.test.ts×1 createOptimisticStore.test.ts×10 optimistic-draft-visibility-3665.test.ts×5 optimistic-list-mutation-matrix.harness.ts×1 optimistic-list-mutation-matrix.test.ts×2 shallow.test.ts×1 woken-transaction-adopts-staged-bump.test.ts×1 treeshake.test.ts×2 verdict-contract.test.ts×1 visibility-oracle-store.states.ts×8 visibility-oracle.states.ts×8 | [ruled, mechanism landed 2026-09-15] A write becomes visible at flush — to every channel — (**ruled 2026-09-08**; supersedes the #2922 mid-tick pull) **A write becomes visible at flush — to every chan… |
 | A29 | amended | `docs/SPEC-ASYNC-SEMANTICS.md:119` | boundaries.ts×1 action.ts×1 constants.ts×1 core.ts×14 effect.ts×1 lanes.ts×1 scheduler.ts×4 signals.ts×1 store.ts×1 | adoption-unchanged-key-read-3706.test.ts×9 body-end-supersession-visibility.test.ts×1 born-held.test.ts×3 boundary-not-born-held-3540.test.ts×4 createProjection.draft-lifetime-3585.test.ts×1 direct-commit-readers-posture.test.ts×1 fallback-born-creator-4428.test.ts×1 fuzz-findings-l2.test.ts×6 held-branch-verdict-reader-4010.test.ts×1 held-conditional-memo.test.ts×1 held-frame-dependencies.test.ts×2 held-frame-verdict-parity.test.ts×1 held-truth-lane-only.test.ts×3 l2-contract.test.ts×1 latest-held-till-flush.test.ts×2 loading-fallback-in-flush-3540.test.ts×6 loading-on-frame-following-3540.test.ts×1 mount-over-foreign-hold-3761.test.ts×1 optimistic-mount-nested-memo-3835.test.ts×1 optimistic-read-lane-not-transaction-3698.test.ts×3 posture-born-held-and-observation.test.ts×1 posture-store-parity.test.ts×6 derived-presence-async-3726.test.ts×3 optimistic-untracked-reads-f3-f5.test.ts×1 store-unchanged-read-independent-write-3688.test.ts×1 tick-scoped-pass-transaction.test.ts×2 treeshake.test.ts×3 verdict-born-into-other-flush-4426.test.ts×1 verdict-mount-first-pass-3851.test.ts×2 verdict-mount-loading-flush-loop.test.ts×2 visibility-oracle-store.states.ts×5 visibility-oracle-store.test.ts×1 visibility-oracle.states.ts×9 visibility-oracle.test.ts×1 write-proposals-3494.test.ts×1 | [ruled, amended in place 2026-09-13 (#3408)] A tracked read served a live transaction's staged value enters that transaction — A tracked computation served a node's staged `_pendingValue` — a value a … |
 | A30 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:259` | async.ts×3 attribution.ts×1 constants.ts×1 core.ts×1 effect.ts×1 lanes.ts×1 scheduler.ts×5 projection.ts×1 | async-landing-deps-3461.test.ts×3 fuzz-findings-l2.test.ts×3 held-conditional-effect.test.ts×1 held-conditional-memo.test.ts×1 held-frame-dependencies.test.ts×2 ispending-in-boundary-on-3528.test.ts×1 lane-frame-deferred-run-3662.test.ts×1 lane-frame-held-lane-3662.test.ts×1 posture-born-held-and-observation.test.ts×1 projection-peek-loop-4342.test.ts×1 treeshake.test.ts×2 write-proposals-3494.test.ts×2 zombie-rerun-after-commit-3546.test.ts×2 | [ruled 2026-09-13 (#3410)] A memo's dependencies are the committed frame's until the frame is replaced — A pass that _staged_ its value has not replaced the committed frame, so the committed value sti… |
-| A31 | live | `docs/SPEC-ASYNC-SEMANTICS.md:133` | boundaries.ts×1 core.ts×1 lanes.ts×1 verdict.ts×2 | fuzz-findings-l2.test.ts×6 ispending-combined-atomic-3442.test.ts×1 latest-pulled-pass-ispending.test.ts×1 probe-pulled-pass-4429.test.ts×1 unowned-memo-ispending-reader-4366.test.ts×1 | [live 2026-09-14 (#3442)] A memo computes under its own lane posture, never its puller's — A memo's value is one shared slot every reader sees, so its pass runs under the lane posture the memo itself … |
+| A31 | live | `docs/SPEC-ASYNC-SEMANTICS.md:133` | boundaries.ts×1 core.ts×1 lanes.ts×1 verdict.ts×2 | fuzz-findings-l2.test.ts×6 ispending-combined-atomic-3442.test.ts×1 latest-pulled-pass-ispending.test.ts×1 probe-pulled-pass-4429.test.ts×1 unowned-memo-ispending-reader-4366.test.ts×1 verdict-memo-held-branch-4544.test.ts×1 | [live 2026-09-14 (#3442)] A memo computes under its own lane posture, never its puller's — A memo's value is one shared slot every reader sees, so its pass runs under the lane posture the memo itself … |
 | A32 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:141` | core.ts×4 lanes.ts×1 seat.ts×1 store.ts×1 | visibility-oracle-store.states.ts×8 visibility-oracle-store.test.ts×1 visibility-oracle.states.ts×9 visibility-oracle.test.ts×1 | [ruled 2026-09-14] Children-forbidden readers see the frame, not the graph — `createTrackedEffect` and `onSettled` callbacks are effect-phase code that runs after the frame is decided. They read the f… |
 | A33 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:275` | boundaries.ts×1 scheduler.ts×2 | async-chain-supersession.test.ts×2 boundary-not-born-held-3540.test.ts×2 create-deferred-3710.test.ts×1 fuzz-findings-l2.test.ts×4 ispending-in-boundary-on-3528.test.ts×2 loading-reset-collects-forwarded-3459.test.ts×3 | [ruled 2026-09-12 (#3375)] A fallback-caught flight holds no transaction; a Loading reset moves the hold onto the boundary — A `<Loading>` boundary showing its fallback is the display of everything un… |
 | A34 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:285` | constants.ts×1 core.ts×6 lanes.ts×2 scheduler.ts×2 store.ts×7 | a34-writes-then-derivations.test.ts×2 continuation-sibling-reader-4146.test.ts×1 createMemo.test.ts×1 derived-write-then-derivation-3733.test.ts×1 finalize-reentry.test.ts×2 fuzz-findings-l2.test.ts×5 held-derivation-not-a-proposal-3612.test.ts×6 optimistic-guess-over-held-slot.test.ts×2 optimistic-list-mutation-matrix.test.ts×1 unchanged-presence-no-hold-3743.test.ts×3 woken-transaction-adopts-staged-bump.test.ts×1 transition-corpse-revival.test.ts×1 treeshake.test.ts×2 visibility-oracle.states.ts×2 write-proposals-3494.test.ts×5 | [ruled 2026-09-16 (#3494)] A write is a proposal: one on a held node entangles its tick; one that nets to the committed value is none — A write proposes a value for a node. **Held, both are suggestion… |

packages/signals/src/core/constants.ts

@@ -73,6 +73,10 @@ export const REACTIVE_PROBE_UNANSWERED = 1 << 19;
  * did not is D-25's hold work while its flight is up (verdict.ts
  * `holdWork`). Per pass. */
 export const REACTIVE_WINDOW = 1 << 21;
+/** #4544 — this pass already holds its transition's staging. Set once, after
+ * the head wipe, from `holdStaging` at `recompute`'s head; `frameRead` tests
+ * it and does not walk deps on the read. Per pass: the tail wipe clears it. */
+export const REACTIVE_HOLD_STAGING = 1 << 20;
 /** An observation-lifecycle node found unobserved by a settle (#2934) while
  * a pass of it was already queued — a source's landing re-enqueued the
  * `_blocked` reader it walks (`settlePendingSource`). The release waits for