Desktop: cold resume paints the REST transcript before a slow session.resume settles (salvage #90130) - #101227
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…e session.resume settles The REST prefetch and the gateway `session.resume` already ran concurrently, but the prefetch result was held until the runtime resume settled. A cold profile build (skills / MCP / memory) can keep `session.resume` pending past the hydration budget while the complete transcript is already in hand, so a Bot Chat sat on the loader and burned its retries with readable history off screen. - Publish the grafted REST snapshot as soon as the prefetch resolves and `isCurrentResume()` holds; the runtime path grafts only its live projection onto that same snapshot, and the post-resume `chatMessageArraysEquivalent` skip keeps reference identity when nothing changed (no second DOM build). - Stamp the eagerly painted page with persisted-display provenance on the runtime state so the warm-path gate admits it on the next switch. - REST fallback after a resume rejection skips the redundant re-publish when the early paint already shows the transcript. Live repro (Electron e2e, session.resume stalled 25s via a temporary backend shim): main never painted within 20s; with this fix the transcript painted 150ms after the row click. Supersedes #90130. Co-authored-by: Alexandre Roumieu <269586168+alexandreroumieu-codeapprentice@users.noreply.github.com>
૮ >ﻌ< ა ci reviewran on bb6636c — fix(desktop): cold resume paints the prefetched REST transcr
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alt-glitch
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This was referenced Sep 2, 2026
12 of 19 tasks
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Summary
Opening a persisted session whose runtime
session.resumeis slow (cold profile build: skills / MCP / memory) now paints the REST transcript as soon as it arrives instead of holding it off screen until the resume RPC settles.Root cause: the prefetch and
session.resumealready ran concurrently, but the prefetched page was only applied afterawait resumePromise. A cold build could hold that await past the Bot Chat hydration budget, so a session with fully readable history sat on the loader and burned its retries. Later mitigations (retryHydrationTimeoutOnce, 60s hydration timeout) retry longer but never paint early.Supersedes #90130 — reimplemented on current
mainwith the same design (early paint under theisCurrentResume()guard, runtime path grafts only its live projection, reference-identity skip after resume). Credit to @alexandreroumieu-codeapprentice, co-authored on the commit.Changes
use-session-actions/index.ts: publish the grafted REST snapshot when the prefetch resolves andisCurrentResume()holds (beforeawait resumePromise); the post-resumechatMessageArraysEquivalentskip keeps reference identity when the acknowledgement changes nothing.persisted-displaytranscript provenance on the runtime state, so the warm-path "hold unproven warm transcripts off the view" gate (b6eb17d) admits it on the next switch.use-session-actions.test.tsx: one new test — REST paints before a deferredsession.resumesettles and the painted array survives (same reference, latch clear) when that resume later rejects. The existing 500-message deferred-resume test now asserts pre-acknowledgement paint + identical reference afterwards.Validation
session.resumestalled 25s (temporary backend shim, not committed)[]while resume pending)e2e/large-session-resume.spec.ts(paint-count budget, one user row)use-session-actions.test.tsx(96) +transcript-provenance.test.tstsc --noEmit,eslinton touched filesLive repro: Electron e2e (built
dist/, real backend, seeded session viaRealSessionBuilder,session.resumehandler stalled 25s via an env-gated sleep) — before: viewport stayed empty for the full 20s window on main; after:E2E stall user message 4visible at 150ms while the resume RPC was still pending.Infographic