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### Overview **Category:** fix **User Impact:** When a user re-pastes (or finishes typing) a link that previously failed to load a preview, the composer now refetches it immediately and can never send a snapshot preview built from the old, stale metadata. **Problem:** The link-preview cache is shared with passive message-list scroll, so a URL that resolved to a negative result (a hard `null` miss or a transient fetch failure) stayed cached and re-usable. Re-pasting that exact link into the composer served the stale negative and never refetched. Worse, the stale metadata was still `snapshotReady`, so a fast clear-then-repaste could attach a **stale snapshot preview tag** to the sent message — a preview that no longer matched the link. **Solution:** A freshly-entering link is forced to refetch, and the composer is fenced against ever shipping a tag built from pre-re-entry metadata. This closes three distinct races surfaced over successive review passes: (1) the shared negative cache being reused on re-entry; (2) the resolver's debounce swallowing a fast clear+re-paste so the re-entry was invisible and the stale tag stayed sendable; and (3) an in-flight media upload started from the stale metadata publishing its tag after fresh metadata had already arrived. Healthy cached hits are never touched (instant card, no redundant fetch), and passive message-list scroll — which never opts in — keeps riding the shared cache exactly as before. <details> <summary>File changes</summary> **desktop/src/shared/lib/useResolvedLinkPreviews.ts** Adds a loader `invalidateNegative(href)` that drops a cached negative result (resolved `null` or transient fail) while leaving healthy hits and in-flight promises alone, and a `refetchNewNegatives` option that invalidates each newly-present href's negative entry before the peek/load loop reads the cache. Also adds an optional `liveHrefs` input so newness is judged against the caller's LIVE (undebounced) content — a debounce-swallowed leave/re-entry of the same URL still counts as new. Because the hook retains its own resolved metadata (the render that scheduled the effect already read the stale negative from it), it also clears its OWN negative key for every re-entered href, so the link renders as pending until the fresh load wins. `buzz://` entity links are skipped (they resolve off the relay, not this cache). **desktop/src/features/messages/ui/useComposerLinkPreviews.tsx** Opts the composer into `refetchNewNegatives` and feeds it the live hrefs. Detects a same-URL re-entry at render time (React batches the empty→repaste renders, so an effect keyed on the live set never observes the transition), then blocks the re-entered href until the resolver's forced refetch visibly cycles through pending: its stale ready tag is dropped from state and excluded from the sendable output until a fresh result re-tags. Only the sendable negative case (`fallback`) is blocked; a healthy (`image`) re-entry keeps its instant card. Adds a per-href upload generation token (`uploadsRef` becomes `Map<href, generation>`): a live re-entry bumps the generation, the upload effect's dedup guard and completion are generation-aware, so an in-flight upload from stale metadata cannot publish its tag after settling and a fresh upload can start even while the superseded one is still in flight. **desktop/src/shared/lib/useResolvedLinkPreviews.test.mjs** Adds resolver-level regressions: `invalidateNegative` drops a cached miss (next load refetches) but preserves a healthy hit (no redundant fetch); transient failure → URL removed → re-entered renders pending/not-`snapshotReady` until a successful retry; and the retained-negative + shared in-flight-fetch + re-entry interleaving clears the local negative regardless of the shared entry's shape. **desktop/src/features/messages/ui/useComposerLinkPreviews.test.mjs** Adds composer-hook regressions driving the REAL hook through the hostile gestures: a fast clear+re-paste inside the debounce window drops the stale tag and holds Send pending until a fresh tag carrying the newly-fetched media lands; and a stale in-flight upload held across the clear+re-paste and fresh-metadata resolution cannot publish its pre-clear tag, while a fresh upload starts and its tag wins. </details> ### Reproduction Steps 1. Paste a link whose preview fails to resolve (force a transient fetch failure) so the composer shows a blank/collapsed card. 2. Clear the composer and re-paste the same link (quickly, within the ~350ms debounce window). 3. Observe the preview refetches immediately rather than reusing the stale negative result, and Send stays disabled until a fresh tag lands. 4. Send the message and confirm the attached preview tag reflects the fresh fetch, never the stale pre-clear metadata. 5. Confirm passive message-list scroll of already-resolved links still shows cards instantly with no extra fetches. ### Notes Scope grew across three review passes from the original single resolver opt-in into a full defense against shipping stale snapshot tags on link re-entry — see the scope-adjustment comment on this PR for the detail. Stacked on #5245 (`tho/link-preview-snapshot-race`), whose rewrite of `useComposerLinkPreviews.tsx` is the sole overlapping file. The transient-retry work stays in #5502, which touches no composer file and remains based on main. --------- Signed-off-by: Taylor Ho <taylorkmho@gmail.com> Signed-off-by: Wes <wesbillman@users.noreply.github.com> Co-authored-by: Wes <wesbillman@users.noreply.github.com> Co-authored-by: Carl <c7ebe626f000404285d3686e1dc74cc07cc60a9754a150041ba132e14bd3e2ec@buzz.block.builderlab.xyz>