readest/apps/readest-app/.claude/memory/instant-highlight-delete-orphan-4773.md

name, description, metadata

name	description	metadata
instant-highlight-delete-orphan-4773	Deleting a just-made highlight leaves the overlay drawn (gone only after reopen); a stale memoized annotationIndex re-draws it	node_type type originSessionId memory project 3a58d242-3867-414c-869a-95a23714b361

#4773 (Android, instant highlight): highlight a word, delete it "within a very short time" → the mark stays painted on the page, vanishing only after reopening the book. Booknote IS soft-deleted (deletedAt set, gone on reopen) but the overlay was re-drawn after removal → orphan.

Root cause — stale memoized index re-draws a deleted annotation. Annotator.tsx re-applies per-location annotations on every relocate via the memoized annotationIndex (useMemo(buildAnnotationIndex(config.booknotes), [config.booknotes])) → selectLocationAnnotations(index, location) → view.addAnnotation(a). buildAnnotationIndex filters deletedAt at BUILD time, but selectLocationAnnotations trusted that and did NOT re-check. The delete (handleHighlight(false)) stamps existing.deletedAt = Date.now() in place on the same booknote object that's still sitting in the index bucket, and removes the overlay (addAnnotation(existing, true)). If the re-apply effect scheduled from the popup-open render flushes AFTER the delete (the "very short time" window — passive effects deferred on Android WebView under rapid taps), selectLocationAnnotations returns the now-deleted object from the pre-deletion snapshot and addAnnotation re-draws it → overlay orphaned. Annotator does NOT re-render on booknote changes (subscribes only to the stable getConfig fn), so the memo stays stale until some other state change recomputes it.

NOT instant-specific in the data layer — instant highlight (useInstantAnnotation) just makes it easy to hit (no popup friction, fast gesture). Delete + re-apply (where the fix lives) is shared with normal highlights. onCreateOverlay reads getConfig FRESH so it's safe; FoliateViewer onLoad re-draw only fires on section load (not a quick delete).

Fix: re-check deletedAt at the READ site, not just at index build:

• selectLocationAnnotations (annotationIndex.ts): if (item.deletedAt) continue; before classifying — covers both the annotations and notes lists.
• The sibling annotationIndex.globals loop in the Annotator re-apply effect: if (annotation.deletedAt) continue; before expandAllRenderedSections (same stale-snapshot hazard for global highlights).

Test: src/__tests__/utils/annotation-index.test.ts — build index with a styled note, then highlight.deletedAt = 123 in place, assert selectLocationAnnotations returns { annotations: [], notes: [] } (red before fix). Verified on Xiaomi 13 Pro (fuxi, WebView) via the CDP lane: real create→delete→immediate-relocate over 4 iterations left overlay count 6→7→6 each time (no orphan); overlay-count metric proven non-blind by a stray-overlay sanity probe. See android-cdp-e2e-lane. Related: instant-highlight-tap-paginate, global-annotation-pageturn-perf-4575.