fix(signals): a verdict reader born into a hold reads it whichever flush runs it (#4426)

.changeset/verdict-born-into-other-flush.md

@@ -0,0 +1,5 @@
+---
+"@solidjs/signals": patch
+---
+
+A verdict reader born into a hold reads that hold's value of a node it holds in every flush, not only the hold's own: one run by another transaction's flush was served the committed value (#4426).

packages/signals/docs/RULES-INDEX.md

@@ -73,7 +73,7 @@ Status legend: **live** stated and standing · **ruled** carries an explicit rul
 | A26 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:111` | — | action-await-contract.test.ts×2 fuzz-findings-l2.test.ts×1 posture-store-parity.test.ts×2 visibility-oracle-store.states.ts×2 visibility-oracle.states.ts×1 visibility-oracle.test.ts×1 | [ruled 2026-07-17] An ambient transaction window is one flush; parking is flush-driven — (**ruled 2026-07-17**, #2913; **enforcement hardened 2026-08-31**, #3141 — parking is flush-driven, and a trans… |
 | A27 | ruled | `docs/SPEC-ASYNC-SEMANTICS.md:303` | — | loading-value.test.ts×2 visibility-oracle.states.ts×18 visibility-oracle.test.ts×1 | [ruled 2026-08-10] The commit-#0 loading window is loading-class and verdict-quiet — (**ruled 2026-08-10**) **The commit-#0 loading window is loading-class and verdict-quiet.** A node born committed v… |
 | 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 seat.ts×1 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 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-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-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 … |
+| 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 seat.ts×1 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 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-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 seat.ts×1 verdict.ts×2 | fuzz-findings-l2.test.ts×6 ispending-combined-atomic-3442.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 … |
 | 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… |

packages/signals/src/core/core.ts

@@ -2022,7 +2022,7 @@ export function read<T>(el: Signal<T> | Computed<T>): T {
     // transaction, reads the screen too.
     if (
       ((observeFlightHook && c._config & CONFIG_VERDICT) || (laneStageHook && passLane?.folded)) &&
-      stagedScreen(c as Computed<any>)
+      stagedScreen(c as Computed<any>, el)
     ) {
       if (__TEST__) shadowActual(SLOT_C);
       return el._value as T;
@@ -2270,7 +2270,7 @@ export function serve(el: Signal<any> | Computed<any>, c: Computed<any> | null):
     (observeFlightHook &&
       c!._config & CONFIG_VERDICT &&
       !((el as Computed<any>)._statusFlags & STATUS_UNINITIALIZED) &&
-      stagedScreen(c!) &&
+      stagedScreen(c!, el) &&
       !throwShown(el))
   ) {
     if (__TEST__) shadowActual(SLOT_C);
@@ -2338,9 +2338,18 @@ export function stagedRead(c: Computed<any>, el?: Signal<any> | Computed<any>):
  * transaction the answer is the seam's and the reader watches it
  * (verdict.ts). A node born into the future has no screen: its staging is
  * its only value (A29). Nor has a reader born into the flush's transaction
- * (`bornInto`, #4010): its branch exists only there. */
-export function stagedScreen(c: Computed<any>): boolean {
-  if (flushTransaction === null || bornInto(c, flushTransaction)) return false;
+ * (`bornInto`, #4010): its branch exists only there — nor, reading `el` a
+ * hold holds, one born into that hold, whichever flush runs it (D-25: the
+ * hold's own work reads plainly). A held node `read` brings here is one
+ * `frameRead` found the reader born into: every other it served the screen
+ * (a lane's node it never asks — CONFIG_OVERRIDE; #4426). */
+export function stagedScreen(c: Computed<any>, el?: Signal<any> | Computed<any>): boolean {
+  if (
+    flushTransaction === null ||
+    bornInto(c, flushTransaction) ||
+    (el?._config! & (CONFIG_HELD | CONFIG_OVERRIDE)) === CONFIG_HELD
+  )
+    return false;
   // A transaction only a `latest()` read opened holds nothing: the staging
   // is the frame's read for a pass in the frame's seat, as it is before the
   // frame has one, and the seam re-derives the pass once only if the flush

packages/signals/tests/verdict-born-into-other-flush-4426.test.ts

@@ -0,0 +1,99 @@
+/**
+ * #4426: a verdict reader born into a hold `T`, re-run by a flush whose
+ * transaction is not `T`, reads `T`'s values (D-25: the hold's own work —
+ * a pass born in its world — reads plainly; D-27, A29: a node born into a
+ * hold has no screen). `read`'s two deciders disagreed: `frameRead` asked
+ * "born into `el`'s hold" and joined the pass, `stagedScreen` asked "born
+ * into the flush's transaction" and served the committed value — so the
+ * effect a `<Show when={s()}>` content mounted for `s = 3` read `s() === 0`,
+ * the value its branch does not exist for.
+ *
+ * Shape: async-gen seed 3289 #911 —
+ * `<Show when={s0()} fallback><span>{isPending(m0)}</span>
+ *  <span fx={[s0(), isPending(m0)]} /></Show>`, `m0 = async(latest(s0) + s0)`.
+ */
+import { expect, it } from "vitest";
+import {
+  createLoadingBoundary,
+  createMemo,
+  createRenderEffect,
+  createRoot,
+  createSignal,
+  flush,
+  isPending,
+  latest
+} from "../src/index.js";
+
+const tick = async () => {
+  for (let i = 0; i < 6; i++) await Promise.resolve();
+  flush();
+  await new Promise(r => setTimeout(r, 0));
+};
+
+it("a verdict reader born into a hold reads the hold's value in another transaction's flush", async () => {
+  const flights: { v: number; resolve: (v: number) => void }[] = [];
+  const settle = () => {
+    while (flights.length) {
+      const f = flights.shift()!;
+      f.resolve(f.v);
+    }
+  };
+  const [s, setS] = createSignal(3);
+  const m = createMemo(
+    () =>
+      new Promise<number>(resolve => {
+        flights.push({ v: 1 + latest(s) + s(), resolve });
+      })
+  );
+  const seen: number[] = [];
+  createRoot(() => {
+    const out = createLoadingBoundary(
+      () => {
+        // <Show when={s()} fallback="[F]">
+        const value = createMemo(() => s());
+        const condition = createMemo(value, { equals: (a, b) => !a === !b, sync: true });
+        return createMemo(
+          () => {
+            if (!condition()) return "[F]";
+            createRenderEffect(
+              () => isPending(m),
+              () => {}
+            );
+            createRenderEffect(
+              () => {
+                seen.push(s());
+                return isPending(m);
+              },
+              () => {}
+            );
+            return "content";
+          },
+          { sync: true }
+        );
+      },
+      () => "[L]"
+    );
+    createRenderEffect(
+      () => {
+        let v: unknown = out;
+        while (typeof v === "function") v = v();
+        return v;
+      },
+      () => {}
+    );
+  });
+  flush();
+  setS(0);
+  flights.shift()!.resolve(7);
+  flush();
+  seen.length = 0;
+  setS(3);
+  for (let r = 0; r < 5; r++) {
+    for (let i = 0; i < 4; i++) await tick();
+    flush();
+    settle();
+  }
+  // The content exists only for a truthy `s`: every pass of its effect reads 3.
+  expect(seen.length).toBeGreaterThan(0);
+  expect(seen.filter(v => v !== 3)).toEqual([]);
+});

packages/web/test/errored-recovery-nested-loading-4425.spec.tsx

@@ -14,7 +14,16 @@
  * refresh landing is the new answer (D-39).
  */
 import { expect, test } from "vitest";
-import { Errored, For, Loading, Show, createMemo, flush, refresh, type Refreshable } from "solid-js";
+import {
+  Errored,
+  For,
+  Loading,
+  Show,
+  createMemo,
+  flush,
+  refresh,
+  type Refreshable
+} from "solid-js";
 import { render } from "../src/index.js";
 
 const tick = async () => {

scripts/size/floor-caps.json

@@ -12,12 +12,12 @@
     "minified": 53585
   },
   "page: base server components (hydrating + dynamic + frames + sf reference)": {
-    "cap": "33.66 KB",
-    "minified": 101605
+    "cap": "33.77 KB",
+    "minified": 101638
   },
   "page: live server components (base + live/GET + action + isPending/latest)": {
-    "cap": "38.76 KB",
-    "minified": 117227
+    "cap": "38.83 KB",
+    "minified": 117331
   },
   "server: floor (getRequestEvent + isServer)": {
     "cap": "1.29 KB",

scripts/size/scenarios.js

@@ -5244,6 +5244,7 @@ module.exports = [
     // 33.66 KB, recorded minified 101,586 -> 101,605 B; CI-measured at 33,645 B
     // (101,605 B minified). Lower only: cap at measured + 10 B rounded up to
     // 0.01 KB; recorded minified never raised.
+    // A verdict reader born into a hold reads it whichever flush runs it (#4426, D-25/D-27; re-measured over next @ 9c4e4a8): 33.66 KB -> 33.77 KB, recorded minified 101,605 -> 101,638 B, measured locally (linux) at 33,755 B brotli. `stagedScreen`'s held-node check (+20 B minified in core.js) on top of next's +13 B over this floor's record (#4452); the brotli is layout. Correctness; a frozen floor, Size-Exception in the PR body. Cap at measured + 10 B rounded up to 0.01 KB; recorded minified = measured.
     limit: floorCaps["page: base server components (hydrating + dynamic + frames + sf reference)"],
     capMinified:
       floorMinified["page: base server components (hydrating + dynamic + frames + sf reference)"],
@@ -5598,6 +5599,7 @@ module.exports = [
     // (117,143 B minified). Lower only: cap at measured + 10 B rounded up to
     // 0.01 KB; recorded minified never raised.
     // A held memo's parked reader re-derives at the seam (#4439, 2026-10-30, over next @ b249ad96): 38.74 KB -> 38.76 KB, recorded minified 117,143 -> 117,227 B (+84 B), measured locally (linux) at 38,741 B brotli. `laneSeams` also re-derives a reader whose pass read a held node, so `isPending` of a memo parked behind a held one turns true. Correctness; a frozen floor, +15 B brotli is under the maintainer's 20 B flag line (2026-10-29), Size-Exception in the PR body. Cap at measured + 10 B rounded up to 0.01 KB; recorded minified = measured.
+    // A verdict reader born into a hold reads it whichever flush runs it (#4426, D-25/D-27; re-measured over next @ 9c4e4a8): 38.81 KB -> 38.83 KB, recorded minified 117,251 -> 117,331 B, measured locally (linux) at 38,817 B brotli. `stagedScreen`'s held-node check (+20 B minified in core.js) on top of next's +13 B over this floor's record (#4452); the brotli is layout. Correctness; a frozen floor, Size-Exception in the PR body. Cap at measured + 10 B rounded up to 0.01 KB; recorded minified = measured.
     limit: floorCaps["page: live server components (base + live/GET + action + isPending/latest)"],
     capMinified:
       floorMinified["page: live server components (base + live/GET + action + isPending/latest)"],
@@ -5767,8 +5769,9 @@ module.exports = [
     // 35.66 KB, recorded minified 107,955 -> 107,974 B; CI-measured at 35,645 B
     // (107,974 B minified). Lower only: cap at measured + 10 B rounded up to
     // 0.01 KB; recorded minified never raised.
-    limit: "35.66 KB",
-    capMinified: 107974,
+    // A verdict reader born into a hold reads it whichever flush runs it (#4426, D-25/D-27; re-measured over next @ 9c4e4a8): 35.66 KB -> 35.72 KB, recorded minified 107,974 -> 108,007 B (+33 B), measured locally (linux) at 35,702 B brotli. `stagedScreen`'s held-node check (+20 B minified in core.js) on top of next's +13 B; the brotli is layout. Correctness. Cap at measured + 10 B rounded up to 0.01 KB; recorded minified = measured.
+    limit: "35.72 KB",
+    capMinified: 108007,
     alias: pageAlias
   },
   {