From aee355fada9d781c2a540f0100816b8847b80b5e Mon Sep 17 00:00:00 2001
From: Duncan Tourolle <duncan@tourolle.paris>
Date: Tue, 22 Sep 2026 21:12:45 -0400
Subject: [PATCH] Make the in-flight claim test wait for the waiter to park

a_second_claim_waits_for_the_first_to_be_released failed on CI: the
second claim came back Some. The waiter thread signalled the main thread
before calling claim, so the main thread could drop the first guard
before the waiter reached the lock. The path was free by then, and the
waiter claimed it outright.

The registry now keeps a test-only count of threads parked in claim,
bumped under the lock just before the condvar wait. The test spins until
that count is one before releasing. The release needs the same lock, so
it can only reach a waiter that is already waiting. Passed 500 runs in a
row.
---
 docs/dev/traceability.md                 |  4 ++--
 ui/dr-ui/src/library/thumbnails_fetch.rs | 22 ++++++++++++++--------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/docs/dev/traceability.md b/docs/dev/traceability.md
index f4490e8..fb2b26c 100644
--- a/docs/dev/traceability.md
+++ b/docs/dev/traceability.md
@@ -120,7 +120,7 @@ _None._
 | FR-NC-4 | [`core/dr-sync-folder/src/lib.rs:197`](../../core/dr-sync-folder/src/lib.rs#L197), [`core/dr-sync-nextcloud/src/propfind.rs:103`](../../core/dr-sync-nextcloud/src/propfind.rs#L103), [`core/dr-sync-nextcloud/src/propfind.rs:51`](../../core/dr-sync-nextcloud/src/propfind.rs#L51), [`core/dr-sync/src/capability.rs:6`](../../core/dr-sync/src/capability.rs#L6), [`core/dr-sync/src/lib.rs:218`](../../core/dr-sync/src/lib.rs#L218), [`core/dr-sync/src/scan.rs:129`](../../core/dr-sync/src/scan.rs#L129), [`ui/dr-ui/src/launch.rs:61`](../../ui/dr-ui/src/launch.rs#L61) |
 | FR-NC-5 | [`core/dr-sync-nextcloud/src/propfind.rs:51`](../../core/dr-sync-nextcloud/src/propfind.rs#L51), [`ui/dr-ui/src/import.rs:488`](../../ui/dr-ui/src/import.rs#L488) |
 | FR-NC-6 | [`ui/dr-ui/src/activity.rs:1`](../../ui/dr-ui/src/activity.rs#L1) |
-| FR-NC-6a | [`core/dr-catalog/src/cache.rs:1`](../../core/dr-catalog/src/cache.rs#L1), [`core/dr-catalog/src/cache.rs:225`](../../core/dr-catalog/src/cache.rs#L225), [`core/dr-catalog/src/schema.rs:1182`](../../core/dr-catalog/src/schema.rs#L1182), [`core/dr-catalog/src/schema.rs:1637`](../../core/dr-catalog/src/schema.rs#L1637), [`core/dr-sync-folder/src/borrow.rs:1`](../../core/dr-sync-folder/src/borrow.rs#L1), [`core/dr-types/src/selector.rs:1`](../../core/dr-types/src/selector.rs#L1), [`core/dr-types/src/settings.rs:1`](../../core/dr-types/src/settings.rs#L1), [`ui/dr-ui/src/collections_ui/rename_menu.rs:75`](../../ui/dr-ui/src/collections_ui/rename_menu.rs#L75), [`ui/dr-ui/src/collections_ui/tree_sync.rs:111`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L111), [`ui/dr-ui/src/collections_ui/tree_sync.rs:387`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L387), [`ui/dr-ui/src/collections_ui/tree_sync.rs:38`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L38), [`ui/dr-ui/src/collections_ui/wiring_tree.rs:560`](../../ui/dr-ui/src/collections_ui/wiring_tree.rs#L560), [`ui/dr-ui/src/lib.rs:1573`](../../ui/dr-ui/src/lib.rs#L1573), [`ui/dr-ui/src/lib.rs:2722`](../../ui/dr-ui/src/lib.rs#L2722), [`ui/dr-ui/src/lib.rs:2793`](../../ui/dr-ui/src/lib.rs#L2793), [`ui/dr-ui/src/lib.rs:3011`](../../ui/dr-ui/src/lib.rs#L3011), [`ui/dr-ui/src/lib.rs:3012`](../../ui/dr-ui/src/lib.rs#L3012), [`ui/dr-ui/src/lib.rs:3051`](../../ui/dr-ui/src/lib.rs#L3051), [`ui/dr-ui/src/library/thumbnails_fetch.rs:118`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L118), [`ui/dr-ui/src/library/thumbnails_fetch.rs:393`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L393), [`ui/dr-ui/src/library/thumbnails_fetch.rs:574`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L574), [`ui/dr-ui/src/library/thumbnails_fetch.rs:711`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L711), [`ui/dr-ui/src/library/thumbnails_fetch.rs:726`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L726), [`ui/dr-ui/src/library/thumbnails_fetch.rs:95`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L95), [`ui/dr-ui/src/library_ui/controller.rs:339`](../../ui/dr-ui/src/library_ui/controller.rs#L339), [`ui/dr-ui/src/library_ui/controller.rs:350`](../../ui/dr-ui/src/library_ui/controller.rs#L350), [`ui/dr-ui/src/library_ui/controller.rs:365`](../../ui/dr-ui/src/library_ui/controller.rs#L365), [`ui/dr-ui/src/library_ui/controller.rs:374`](../../ui/dr-ui/src/library_ui/controller.rs#L374), [`ui/dr-ui/src/library_ui/controller.rs:382`](../../ui/dr-ui/src/library_ui/controller.rs#L382), [`ui/dr-ui/src/library_ui/controller.rs:512`](../../ui/dr-ui/src/library_ui/controller.rs#L512), [`ui/dr-ui/src/library_ui/controller.rs:522`](../../ui/dr-ui/src/library_ui/controller.rs#L522), [`ui/dr-ui/src/library_ui/controller.rs:537`](../../ui/dr-ui/src/library_ui/controller.rs#L537), [`ui/dr-ui/src/library_ui/controller.rs:584`](../../ui/dr-ui/src/library_ui/controller.rs#L584), [`ui/dr-ui/src/library_ui/controller.rs:599`](../../ui/dr-ui/src/library_ui/controller.rs#L599), [`ui/dr-ui/src/library_ui/controller.rs:673`](../../ui/dr-ui/src/library_ui/controller.rs#L673), [`ui/dr-ui/src/library_ui/controller.rs:704`](../../ui/dr-ui/src/library_ui/controller.rs#L704), [`ui/dr-ui/src/library_ui/controller.rs:716`](../../ui/dr-ui/src/library_ui/controller.rs#L716), [`ui/dr-ui/src/library_ui/filter_bar.rs:424`](../../ui/dr-ui/src/library_ui/filter_bar.rs#L424), [`ui/dr-ui/src/library_ui/filter_bar.rs:444`](../../ui/dr-ui/src/library_ui/filter_bar.rs#L444), [`ui/dr-ui/src/library_ui/offline.rs:196`](../../ui/dr-ui/src/library_ui/offline.rs#L196), [`ui/dr-ui/src/library_ui/offline.rs:20`](../../ui/dr-ui/src/library_ui/offline.rs#L20), [`ui/dr-ui/src/library_ui/offline.rs:261`](../../ui/dr-ui/src/library_ui/offline.rs#L261), [`ui/dr-ui/src/library_ui/offline.rs:407`](../../ui/dr-ui/src/library_ui/offline.rs#L407), [`ui/dr-ui/src/library_ui/offline.rs:528`](../../ui/dr-ui/src/library_ui/offline.rs#L528), [`ui/dr-ui/src/library_ui/offline.rs:93`](../../ui/dr-ui/src/library_ui/offline.rs#L93), [`ui/dr-ui/src/library_ui/window.rs:228`](../../ui/dr-ui/src/library_ui/window.rs#L228), [`ui/dr-ui/src/settings_store.rs:1`](../../ui/dr-ui/src/settings_store.rs#L1), [`ui/dr-ui/src/settings_ui.rs:157`](../../ui/dr-ui/src/settings_ui.rs#L157), [`ui/dr-ui/src/settings_ui.rs:1`](../../ui/dr-ui/src/settings_ui.rs#L1), [`ui/dr-ui/src/settings_ui.rs:542`](../../ui/dr-ui/src/settings_ui.rs#L542), [`ui/dr-ui/ui/app.slint:1302`](../../ui/dr-ui/ui/app.slint#L1302), [`ui/dr-ui/ui/app.slint:2854`](../../ui/dr-ui/ui/app.slint#L2854), [`ui/dr-ui/ui/app.slint:426`](../../ui/dr-ui/ui/app.slint#L426), [`ui/dr-ui/ui/collections.slint:1037`](../../ui/dr-ui/ui/collections.slint#L1037), [`ui/dr-ui/ui/collections.slint:1048`](../../ui/dr-ui/ui/collections.slint#L1048), [`ui/dr-ui/ui/collections.slint:1127`](../../ui/dr-ui/ui/collections.slint#L1127), [`ui/dr-ui/ui/collections.slint:1228`](../../ui/dr-ui/ui/collections.slint#L1228), [`ui/dr-ui/ui/collections.slint:1236`](../../ui/dr-ui/ui/collections.slint#L1236), [`ui/dr-ui/ui/collections.slint:272`](../../ui/dr-ui/ui/collections.slint#L272), [`ui/dr-ui/ui/collections.slint:424`](../../ui/dr-ui/ui/collections.slint#L424), [`ui/dr-ui/ui/collections.slint:433`](../../ui/dr-ui/ui/collections.slint#L433), [`ui/dr-ui/ui/collections.slint:436`](../../ui/dr-ui/ui/collections.slint#L436), [`ui/dr-ui/ui/collections.slint:482`](../../ui/dr-ui/ui/collections.slint#L482), [`ui/dr-ui/ui/collections.slint:52`](../../ui/dr-ui/ui/collections.slint#L52), [`ui/dr-ui/ui/collections.slint:720`](../../ui/dr-ui/ui/collections.slint#L720), [`ui/dr-ui/ui/collections.slint:877`](../../ui/dr-ui/ui/collections.slint#L877), [`ui/dr-ui/ui/collections.slint:91`](../../ui/dr-ui/ui/collections.slint#L91), [`ui/dr-ui/ui/icons.slint:262`](../../ui/dr-ui/ui/icons.slint#L262), [`ui/dr-ui/ui/settings.slint:114`](../../ui/dr-ui/ui/settings.slint#L114), [`ui/dr-ui/ui/settings.slint:656`](../../ui/dr-ui/ui/settings.slint#L656) |
+| FR-NC-6a | [`core/dr-catalog/src/cache.rs:1`](../../core/dr-catalog/src/cache.rs#L1), [`core/dr-catalog/src/cache.rs:225`](../../core/dr-catalog/src/cache.rs#L225), [`core/dr-catalog/src/schema.rs:1182`](../../core/dr-catalog/src/schema.rs#L1182), [`core/dr-catalog/src/schema.rs:1637`](../../core/dr-catalog/src/schema.rs#L1637), [`core/dr-sync-folder/src/borrow.rs:1`](../../core/dr-sync-folder/src/borrow.rs#L1), [`core/dr-types/src/selector.rs:1`](../../core/dr-types/src/selector.rs#L1), [`core/dr-types/src/settings.rs:1`](../../core/dr-types/src/settings.rs#L1), [`ui/dr-ui/src/collections_ui/rename_menu.rs:75`](../../ui/dr-ui/src/collections_ui/rename_menu.rs#L75), [`ui/dr-ui/src/collections_ui/tree_sync.rs:111`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L111), [`ui/dr-ui/src/collections_ui/tree_sync.rs:387`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L387), [`ui/dr-ui/src/collections_ui/tree_sync.rs:38`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L38), [`ui/dr-ui/src/collections_ui/wiring_tree.rs:560`](../../ui/dr-ui/src/collections_ui/wiring_tree.rs#L560), [`ui/dr-ui/src/lib.rs:1573`](../../ui/dr-ui/src/lib.rs#L1573), [`ui/dr-ui/src/lib.rs:2722`](../../ui/dr-ui/src/lib.rs#L2722), [`ui/dr-ui/src/lib.rs:2793`](../../ui/dr-ui/src/lib.rs#L2793), [`ui/dr-ui/src/lib.rs:3011`](../../ui/dr-ui/src/lib.rs#L3011), [`ui/dr-ui/src/lib.rs:3012`](../../ui/dr-ui/src/lib.rs#L3012), [`ui/dr-ui/src/lib.rs:3051`](../../ui/dr-ui/src/lib.rs#L3051), [`ui/dr-ui/src/library/thumbnails_fetch.rs:118`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L118), [`ui/dr-ui/src/library/thumbnails_fetch.rs:393`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L393), [`ui/dr-ui/src/library/thumbnails_fetch.rs:574`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L574), [`ui/dr-ui/src/library/thumbnails_fetch.rs:718`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L718), [`ui/dr-ui/src/library/thumbnails_fetch.rs:733`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L733), [`ui/dr-ui/src/library/thumbnails_fetch.rs:95`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L95), [`ui/dr-ui/src/library_ui/controller.rs:339`](../../ui/dr-ui/src/library_ui/controller.rs#L339), [`ui/dr-ui/src/library_ui/controller.rs:350`](../../ui/dr-ui/src/library_ui/controller.rs#L350), [`ui/dr-ui/src/library_ui/controller.rs:365`](../../ui/dr-ui/src/library_ui/controller.rs#L365), [`ui/dr-ui/src/library_ui/controller.rs:374`](../../ui/dr-ui/src/library_ui/controller.rs#L374), [`ui/dr-ui/src/library_ui/controller.rs:382`](../../ui/dr-ui/src/library_ui/controller.rs#L382), [`ui/dr-ui/src/library_ui/controller.rs:512`](../../ui/dr-ui/src/library_ui/controller.rs#L512), [`ui/dr-ui/src/library_ui/controller.rs:522`](../../ui/dr-ui/src/library_ui/controller.rs#L522), [`ui/dr-ui/src/library_ui/controller.rs:537`](../../ui/dr-ui/src/library_ui/controller.rs#L537), [`ui/dr-ui/src/library_ui/controller.rs:584`](../../ui/dr-ui/src/library_ui/controller.rs#L584), [`ui/dr-ui/src/library_ui/controller.rs:599`](../../ui/dr-ui/src/library_ui/controller.rs#L599), [`ui/dr-ui/src/library_ui/controller.rs:673`](../../ui/dr-ui/src/library_ui/controller.rs#L673), [`ui/dr-ui/src/library_ui/controller.rs:704`](../../ui/dr-ui/src/library_ui/controller.rs#L704), [`ui/dr-ui/src/library_ui/controller.rs:716`](../../ui/dr-ui/src/library_ui/controller.rs#L716), [`ui/dr-ui/src/library_ui/filter_bar.rs:424`](../../ui/dr-ui/src/library_ui/filter_bar.rs#L424), [`ui/dr-ui/src/library_ui/filter_bar.rs:444`](../../ui/dr-ui/src/library_ui/filter_bar.rs#L444), [`ui/dr-ui/src/library_ui/offline.rs:196`](../../ui/dr-ui/src/library_ui/offline.rs#L196), [`ui/dr-ui/src/library_ui/offline.rs:20`](../../ui/dr-ui/src/library_ui/offline.rs#L20), [`ui/dr-ui/src/library_ui/offline.rs:261`](../../ui/dr-ui/src/library_ui/offline.rs#L261), [`ui/dr-ui/src/library_ui/offline.rs:407`](../../ui/dr-ui/src/library_ui/offline.rs#L407), [`ui/dr-ui/src/library_ui/offline.rs:528`](../../ui/dr-ui/src/library_ui/offline.rs#L528), [`ui/dr-ui/src/library_ui/offline.rs:93`](../../ui/dr-ui/src/library_ui/offline.rs#L93), [`ui/dr-ui/src/library_ui/window.rs:228`](../../ui/dr-ui/src/library_ui/window.rs#L228), [`ui/dr-ui/src/settings_store.rs:1`](../../ui/dr-ui/src/settings_store.rs#L1), [`ui/dr-ui/src/settings_ui.rs:157`](../../ui/dr-ui/src/settings_ui.rs#L157), [`ui/dr-ui/src/settings_ui.rs:1`](../../ui/dr-ui/src/settings_ui.rs#L1), [`ui/dr-ui/src/settings_ui.rs:542`](../../ui/dr-ui/src/settings_ui.rs#L542), [`ui/dr-ui/ui/app.slint:1302`](../../ui/dr-ui/ui/app.slint#L1302), [`ui/dr-ui/ui/app.slint:2854`](../../ui/dr-ui/ui/app.slint#L2854), [`ui/dr-ui/ui/app.slint:426`](../../ui/dr-ui/ui/app.slint#L426), [`ui/dr-ui/ui/collections.slint:1037`](../../ui/dr-ui/ui/collections.slint#L1037), [`ui/dr-ui/ui/collections.slint:1048`](../../ui/dr-ui/ui/collections.slint#L1048), [`ui/dr-ui/ui/collections.slint:1127`](../../ui/dr-ui/ui/collections.slint#L1127), [`ui/dr-ui/ui/collections.slint:1228`](../../ui/dr-ui/ui/collections.slint#L1228), [`ui/dr-ui/ui/collections.slint:1236`](../../ui/dr-ui/ui/collections.slint#L1236), [`ui/dr-ui/ui/collections.slint:272`](../../ui/dr-ui/ui/collections.slint#L272), [`ui/dr-ui/ui/collections.slint:424`](../../ui/dr-ui/ui/collections.slint#L424), [`ui/dr-ui/ui/collections.slint:433`](../../ui/dr-ui/ui/collections.slint#L433), [`ui/dr-ui/ui/collections.slint:436`](../../ui/dr-ui/ui/collections.slint#L436), [`ui/dr-ui/ui/collections.slint:482`](../../ui/dr-ui/ui/collections.slint#L482), [`ui/dr-ui/ui/collections.slint:52`](../../ui/dr-ui/ui/collections.slint#L52), [`ui/dr-ui/ui/collections.slint:720`](../../ui/dr-ui/ui/collections.slint#L720), [`ui/dr-ui/ui/collections.slint:877`](../../ui/dr-ui/ui/collections.slint#L877), [`ui/dr-ui/ui/collections.slint:91`](../../ui/dr-ui/ui/collections.slint#L91), [`ui/dr-ui/ui/icons.slint:262`](../../ui/dr-ui/ui/icons.slint#L262), [`ui/dr-ui/ui/settings.slint:114`](../../ui/dr-ui/ui/settings.slint#L114), [`ui/dr-ui/ui/settings.slint:656`](../../ui/dr-ui/ui/settings.slint#L656) |
 | FR-NC-6b | [`ui/dr-ui/src/library_ui/offline.rs:261`](../../ui/dr-ui/src/library_ui/offline.rs#L261), [`ui/dr-ui/src/memory.rs:1`](../../ui/dr-ui/src/memory.rs#L1) |
 | FR-NC-6c | [`core/dr-catalog/src/cache.rs:225`](../../core/dr-catalog/src/cache.rs#L225), [`core/dr-sync-folder/src/borrow.rs:1`](../../core/dr-sync-folder/src/borrow.rs#L1), [`core/dr-sync-folder/src/lib.rs:197`](../../core/dr-sync-folder/src/lib.rs#L197), [`core/dr-sync-folder/src/lib.rs:73`](../../core/dr-sync-folder/src/lib.rs#L73), [`core/dr-sync-folder/src/lib.rs:818`](../../core/dr-sync-folder/src/lib.rs#L818), [`core/dr-sync-folder/src/lib.rs:857`](../../core/dr-sync-folder/src/lib.rs#L857), [`core/dr-sync-folder/src/vfs.rs:1`](../../core/dr-sync-folder/src/vfs.rs#L1), [`core/dr-sync-nextcloud/src/desktop_client.rs:172`](../../core/dr-sync-nextcloud/src/desktop_client.rs#L172), [`core/dr-sync-nextcloud/src/desktop_client.rs:35`](../../core/dr-sync-nextcloud/src/desktop_client.rs#L35), [`core/dr-sync/src/capability.rs:41`](../../core/dr-sync/src/capability.rs#L41), [`core/dr-sync/src/error.rs:39`](../../core/dr-sync/src/error.rs#L39), [`core/dr-sync/src/lib.rs:158`](../../core/dr-sync/src/lib.rs#L158), [`core/dr-sync/src/types.rs:101`](../../core/dr-sync/src/types.rs#L101), [`core/dr-types/src/lib.rs:122`](../../core/dr-types/src/lib.rs#L122), [`core/dr-types/src/lib.rs:204`](../../core/dr-types/src/lib.rs#L204), [`ui/dr-ui/src/activity.rs:1`](../../ui/dr-ui/src/activity.rs#L1), [`ui/dr-ui/src/collections_ui/tree_sync.rs:111`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L111), [`ui/dr-ui/src/collections_ui/tree_sync.rs:387`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L387), [`ui/dr-ui/src/collections_ui/tree_sync.rs:38`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L38), [`ui/dr-ui/src/derived_sync.rs:1053`](../../ui/dr-ui/src/derived_sync.rs#L1053), [`ui/dr-ui/src/derived_sync.rs:652`](../../ui/dr-ui/src/derived_sync.rs#L652), [`ui/dr-ui/src/library/sidecar.rs:531`](../../ui/dr-ui/src/library/sidecar.rs#L531), [`ui/dr-ui/src/library/sweep.rs:677`](../../ui/dr-ui/src/library/sweep.rs#L677), [`ui/dr-ui/src/library/thumbnails_fetch.rs:215`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L215), [`ui/dr-ui/src/library/thumbnails_fetch.rs:305`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L305), [`ui/dr-ui/src/library_ui/offline.rs:20`](../../ui/dr-ui/src/library_ui/offline.rs#L20), [`ui/dr-ui/src/library_ui/offline.rs:310`](../../ui/dr-ui/src/library_ui/offline.rs#L310), [`ui/dr-ui/src/library_ui/offline.rs:93`](../../ui/dr-ui/src/library_ui/offline.rs#L93), [`ui/dr-ui/src/remote.rs:40`](../../ui/dr-ui/src/remote.rs#L40), [`ui/dr-ui/src/repairs.rs:1140`](../../ui/dr-ui/src/repairs.rs#L1140), [`ui/dr-ui/ui/collections.slint:272`](../../ui/dr-ui/ui/collections.slint#L272), [`ui/dr-ui/ui/collections.slint:877`](../../ui/dr-ui/ui/collections.slint#L877), [`ui/dr-ui/ui/icons.slint:262`](../../ui/dr-ui/ui/icons.slint#L262) |
 | FR-NC-6d | [`core/dr-sync-folder/src/borrow.rs:1`](../../core/dr-sync-folder/src/borrow.rs#L1), [`core/dr-sync-folder/src/lib.rs:1`](../../core/dr-sync-folder/src/lib.rs#L1), [`core/dr-sync-folder/src/vfs.rs:1`](../../core/dr-sync-folder/src/vfs.rs#L1) |
@@ -146,7 +146,7 @@ _None._
 | FR-UI-1 | [`core/dr-types/src/settings.rs:1377`](../../core/dr-types/src/settings.rs#L1377), [`core/dr-types/src/settings.rs:492`](../../core/dr-types/src/settings.rs#L492), [`core/dr-types/src/settings.rs:512`](../../core/dr-types/src/settings.rs#L512), [`ui/dr-ui/src/develop_ui.rs:204`](../../ui/dr-ui/src/develop_ui.rs#L204), [`ui/dr-ui/src/lib.rs:110`](../../ui/dr-ui/src/lib.rs#L110), [`ui/dr-ui/src/lib.rs:125`](../../ui/dr-ui/src/lib.rs#L125), [`ui/dr-ui/src/lib.rs:147`](../../ui/dr-ui/src/lib.rs#L147), [`ui/dr-ui/src/lib.rs:3202`](../../ui/dr-ui/src/lib.rs#L3202), [`ui/dr-ui/src/lib.rs:3221`](../../ui/dr-ui/src/lib.rs#L3221), [`ui/dr-ui/src/lib.rs:3248`](../../ui/dr-ui/src/lib.rs#L3248), [`ui/dr-ui/src/lib.rs:3299`](../../ui/dr-ui/src/lib.rs#L3299), [`ui/dr-ui/src/lib.rs:3332`](../../ui/dr-ui/src/lib.rs#L3332), [`ui/dr-ui/src/masks_ui.rs:1537`](../../ui/dr-ui/src/masks_ui.rs#L1537), [`ui/dr-ui/src/settings_ui.rs:179`](../../ui/dr-ui/src/settings_ui.rs#L179), [`ui/dr-ui/ui/adjust.slint:974`](../../ui/dr-ui/ui/adjust.slint#L974), [`ui/dr-ui/ui/app.slint:2533`](../../ui/dr-ui/ui/app.slint#L2533), [`ui/dr-ui/ui/app.slint:605`](../../ui/dr-ui/ui/app.slint#L605), [`ui/dr-ui/ui/app.slint:709`](../../ui/dr-ui/ui/app.slint#L709), [`ui/dr-ui/ui/identity.slint:246`](../../ui/dr-ui/ui/identity.slint#L246), [`ui/dr-ui/ui/library.slint:1346`](../../ui/dr-ui/ui/library.slint#L1346), [`ui/dr-ui/ui/settings.slint:122`](../../ui/dr-ui/ui/settings.slint#L122), [`ui/dr-ui/ui/settings.slint:681`](../../ui/dr-ui/ui/settings.slint#L681), [`ui/dr-ui/ui/toolrail.slint:156`](../../ui/dr-ui/ui/toolrail.slint#L156), [`ui/dr-ui/ui/toolrail.slint:89`](../../ui/dr-ui/ui/toolrail.slint#L89) |
 | FR-UI-2 | [`ui/dr-ui/src/collections_ui/controller.rs:45`](../../ui/dr-ui/src/collections_ui/controller.rs#L45), [`ui/dr-ui/src/collections_ui/controller.rs:83`](../../ui/dr-ui/src/collections_ui/controller.rs#L83), [`ui/dr-ui/src/collections_ui/drag.rs:246`](../../ui/dr-ui/src/collections_ui/drag.rs#L246), [`ui/dr-ui/src/collections_ui/drag.rs:256`](../../ui/dr-ui/src/collections_ui/drag.rs#L256), [`ui/dr-ui/src/collections_ui/press.rs:453`](../../ui/dr-ui/src/collections_ui/press.rs#L453), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:121`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L121), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:138`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L138), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:415`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L415), [`ui/dr-ui/src/collections_ui/wiring_tree.rs:287`](../../ui/dr-ui/src/collections_ui/wiring_tree.rs#L287), [`ui/dr-ui/src/gestures.rs:1`](../../ui/dr-ui/src/gestures.rs#L1), [`ui/dr-ui/src/lib.rs:110`](../../ui/dr-ui/src/lib.rs#L110), [`ui/dr-ui/src/library_ui/filter_bar.rs:295`](../../ui/dr-ui/src/library_ui/filter_bar.rs#L295), [`ui/dr-ui/src/library_ui/window.rs:873`](../../ui/dr-ui/src/library_ui/window.rs#L873), [`ui/dr-ui/ui/app.slint:112`](../../ui/dr-ui/ui/app.slint#L112), [`ui/dr-ui/ui/app.slint:693`](../../ui/dr-ui/ui/app.slint#L693), [`ui/dr-ui/ui/collections.slint:1253`](../../ui/dr-ui/ui/collections.slint#L1253), [`ui/dr-ui/ui/controls.slint:626`](../../ui/dr-ui/ui/controls.slint#L626), [`ui/dr-ui/ui/gestures.slint:1`](../../ui/dr-ui/ui/gestures.slint#L1), [`ui/dr-ui/ui/library.slint:1235`](../../ui/dr-ui/ui/library.slint#L1235), [`ui/dr-ui/ui/library.slint:1268`](../../ui/dr-ui/ui/library.slint#L1268), [`ui/dr-ui/ui/library.slint:1557`](../../ui/dr-ui/ui/library.slint#L1557), [`ui/dr-ui/ui/library.slint:1564`](../../ui/dr-ui/ui/library.slint#L1564), [`ui/dr-ui/ui/library.slint:1661`](../../ui/dr-ui/ui/library.slint#L1661), [`ui/dr-ui/ui/library.slint:2898`](../../ui/dr-ui/ui/library.slint#L2898), [`ui/dr-ui/ui/library.slint:4647`](../../ui/dr-ui/ui/library.slint#L4647), [`ui/dr-ui/ui/library.slint:554`](../../ui/dr-ui/ui/library.slint#L554), [`ui/dr-ui/ui/presets.slint:19`](../../ui/dr-ui/ui/presets.slint#L19), [`ui/dr-ui/ui/settings.slint:136`](../../ui/dr-ui/ui/settings.slint#L136) |
 | FR-UI-3 | [`ui/dr-ui/src/collections_ui/controller.rs:138`](../../ui/dr-ui/src/collections_ui/controller.rs#L138), [`ui/dr-ui/src/collections_ui/controller.rs:343`](../../ui/dr-ui/src/collections_ui/controller.rs#L343), [`ui/dr-ui/src/collections_ui/controller.rs:356`](../../ui/dr-ui/src/collections_ui/controller.rs#L356), [`ui/dr-ui/src/collections_ui/wiring_tree.rs:287`](../../ui/dr-ui/src/collections_ui/wiring_tree.rs#L287), [`ui/dr-ui/src/develop/masks.rs:360`](../../ui/dr-ui/src/develop/masks.rs#L360), [`ui/dr-ui/src/develop/repairs.rs:49`](../../ui/dr-ui/src/develop/repairs.rs#L49), [`ui/dr-ui/src/library_ui/grid.rs:168`](../../ui/dr-ui/src/library_ui/grid.rs#L168), [`ui/dr-ui/src/masks_ui.rs:1629`](../../ui/dr-ui/src/masks_ui.rs#L1629), [`ui/dr-ui/src/masks_ui.rs:1651`](../../ui/dr-ui/src/masks_ui.rs#L1651), [`ui/dr-ui/src/masks_ui.rs:339`](../../ui/dr-ui/src/masks_ui.rs#L339), [`ui/dr-ui/src/spots_ui.rs:19`](../../ui/dr-ui/src/spots_ui.rs#L19), [`ui/dr-ui/ui/app.slint:2076`](../../ui/dr-ui/ui/app.slint#L2076), [`ui/dr-ui/ui/collections.slint:1127`](../../ui/dr-ui/ui/collections.slint#L1127), [`ui/dr-ui/ui/collections.slint:4`](../../ui/dr-ui/ui/collections.slint#L4), [`ui/dr-ui/ui/collections.slint:75`](../../ui/dr-ui/ui/collections.slint#L75), [`ui/dr-ui/ui/collections.slint:877`](../../ui/dr-ui/ui/collections.slint#L877), [`ui/dr-ui/ui/masks.slint:1216`](../../ui/dr-ui/ui/masks.slint#L1216), [`ui/dr-ui/ui/widgets.slint:71`](../../ui/dr-ui/ui/widgets.slint#L71) |
-| FR-UI-4 | [`tools/traceability/src/gestures.rs:1`](../../tools/traceability/src/gestures.rs#L1), [`ui/dr-ui/src/collections_ui/controller.rs:138`](../../ui/dr-ui/src/collections_ui/controller.rs#L138), [`ui/dr-ui/src/collections_ui/controller.rs:343`](../../ui/dr-ui/src/collections_ui/controller.rs#L343), [`ui/dr-ui/src/collections_ui/controller.rs:356`](../../ui/dr-ui/src/collections_ui/controller.rs#L356), [`ui/dr-ui/src/collections_ui/controller.rs:45`](../../ui/dr-ui/src/collections_ui/controller.rs#L45), [`ui/dr-ui/src/collections_ui/controller.rs:46`](../../ui/dr-ui/src/collections_ui/controller.rs#L46), [`ui/dr-ui/src/collections_ui/controller.rs:55`](../../ui/dr-ui/src/collections_ui/controller.rs#L55), [`ui/dr-ui/src/collections_ui/controller.rs:83`](../../ui/dr-ui/src/collections_ui/controller.rs#L83), [`ui/dr-ui/src/collections_ui/drag.rs:246`](../../ui/dr-ui/src/collections_ui/drag.rs#L246), [`ui/dr-ui/src/collections_ui/drag.rs:256`](../../ui/dr-ui/src/collections_ui/drag.rs#L256), [`ui/dr-ui/src/collections_ui/press.rs:258`](../../ui/dr-ui/src/collections_ui/press.rs#L258), [`ui/dr-ui/src/collections_ui/press.rs:278`](../../ui/dr-ui/src/collections_ui/press.rs#L278), [`ui/dr-ui/src/collections_ui/press.rs:453`](../../ui/dr-ui/src/collections_ui/press.rs#L453), [`ui/dr-ui/src/collections_ui/press.rs:490`](../../ui/dr-ui/src/collections_ui/press.rs#L490), [`ui/dr-ui/src/collections_ui/press.rs:54`](../../ui/dr-ui/src/collections_ui/press.rs#L54), [`ui/dr-ui/src/collections_ui/tree_sync.rs:339`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L339), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:121`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L121), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:138`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L138), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:264`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L264), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:415`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L415), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:444`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L444), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:577`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L577), [`ui/dr-ui/src/collections_ui/wiring_tree.rs:287`](../../ui/dr-ui/src/collections_ui/wiring_tree.rs#L287), [`ui/dr-ui/src/collections_ui/wiring_tree.rs:344`](../../ui/dr-ui/src/collections_ui/wiring_tree.rs#L344), [`ui/dr-ui/src/develop/framing.rs:444`](../../ui/dr-ui/src/develop/framing.rs#L444), [`ui/dr-ui/src/develop/framing.rs:469`](../../ui/dr-ui/src/develop/framing.rs#L469), [`ui/dr-ui/src/develop/framing.rs:480`](../../ui/dr-ui/src/develop/framing.rs#L480), [`ui/dr-ui/src/develop/framing.rs:494`](../../ui/dr-ui/src/develop/framing.rs#L494), [`ui/dr-ui/src/develop/framing.rs:668`](../../ui/dr-ui/src/develop/framing.rs#L668), [`ui/dr-ui/src/develop/framing.rs:699`](../../ui/dr-ui/src/develop/framing.rs#L699), [`ui/dr-ui/src/develop/framing.rs:720`](../../ui/dr-ui/src/develop/framing.rs#L720), [`ui/dr-ui/src/develop_ui.rs:812`](../../ui/dr-ui/src/develop_ui.rs#L812), [`ui/dr-ui/src/gesture_book.rs:3`](../../ui/dr-ui/src/gesture_book.rs#L3), [`ui/dr-ui/src/gestures.rs:1`](../../ui/dr-ui/src/gestures.rs#L1), [`ui/dr-ui/src/lib.rs:1285`](../../ui/dr-ui/src/lib.rs#L1285), [`ui/dr-ui/src/lib.rs:1573`](../../ui/dr-ui/src/lib.rs#L1573), [`ui/dr-ui/src/lib.rs:2574`](../../ui/dr-ui/src/lib.rs#L2574), [`ui/dr-ui/src/lib.rs:2793`](../../ui/dr-ui/src/lib.rs#L2793), [`ui/dr-ui/src/lib.rs:2853`](../../ui/dr-ui/src/lib.rs#L2853), [`ui/dr-ui/src/lib.rs:3012`](../../ui/dr-ui/src/lib.rs#L3012), [`ui/dr-ui/src/lib.rs:3452`](../../ui/dr-ui/src/lib.rs#L3452), [`ui/dr-ui/src/lib.rs:462`](../../ui/dr-ui/src/lib.rs#L462), [`ui/dr-ui/src/lib.rs:491`](../../ui/dr-ui/src/lib.rs#L491), [`ui/dr-ui/src/library/thumbnails_fetch.rs:711`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L711), [`ui/dr-ui/src/library/thumbnails_fetch.rs:726`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L726), [`ui/dr-ui/src/library_ui/controller.rs:382`](../../ui/dr-ui/src/library_ui/controller.rs#L382), [`ui/dr-ui/src/library_ui/controller.rs:522`](../../ui/dr-ui/src/library_ui/controller.rs#L522), [`ui/dr-ui/src/library_ui/controller.rs:599`](../../ui/dr-ui/src/library_ui/controller.rs#L599), [`ui/dr-ui/src/library_ui/filter_bar.rs:444`](../../ui/dr-ui/src/library_ui/filter_bar.rs#L444), [`ui/dr-ui/src/library_ui/grid.rs:168`](../../ui/dr-ui/src/library_ui/grid.rs#L168), [`ui/dr-ui/src/library_ui/grid.rs:182`](../../ui/dr-ui/src/library_ui/grid.rs#L182), [`ui/dr-ui/src/library_ui/grid.rs:256`](../../ui/dr-ui/src/library_ui/grid.rs#L256), [`ui/dr-ui/src/library_ui/grid.rs:393`](../../ui/dr-ui/src/library_ui/grid.rs#L393), [`ui/dr-ui/src/library_ui/grid.rs:423`](../../ui/dr-ui/src/library_ui/grid.rs#L423), [`ui/dr-ui/src/settings_ui.rs:157`](../../ui/dr-ui/src/settings_ui.rs#L157), [`ui/dr-ui/src/settings_ui.rs:542`](../../ui/dr-ui/src/settings_ui.rs#L542), [`ui/dr-ui/ui/app.slint:1772`](../../ui/dr-ui/ui/app.slint#L1772), [`ui/dr-ui/ui/app.slint:1894`](../../ui/dr-ui/ui/app.slint#L1894), [`ui/dr-ui/ui/app.slint:212`](../../ui/dr-ui/ui/app.slint#L212), [`ui/dr-ui/ui/app.slint:2300`](../../ui/dr-ui/ui/app.slint#L2300), [`ui/dr-ui/ui/app.slint:2433`](../../ui/dr-ui/ui/app.slint#L2433), [`ui/dr-ui/ui/app.slint:2904`](../../ui/dr-ui/ui/app.slint#L2904), [`ui/dr-ui/ui/collections.slint:1253`](../../ui/dr-ui/ui/collections.slint#L1253), [`ui/dr-ui/ui/collections.slint:75`](../../ui/dr-ui/ui/collections.slint#L75), [`ui/dr-ui/ui/gestures.slint:1`](../../ui/dr-ui/ui/gestures.slint#L1), [`ui/dr-ui/ui/library.slint:1235`](../../ui/dr-ui/ui/library.slint#L1235), [`ui/dr-ui/ui/library.slint:1262`](../../ui/dr-ui/ui/library.slint#L1262), [`ui/dr-ui/ui/library.slint:1268`](../../ui/dr-ui/ui/library.slint#L1268), [`ui/dr-ui/ui/library.slint:1323`](../../ui/dr-ui/ui/library.slint#L1323), [`ui/dr-ui/ui/library.slint:1532`](../../ui/dr-ui/ui/library.slint#L1532), [`ui/dr-ui/ui/library.slint:1557`](../../ui/dr-ui/ui/library.slint#L1557), [`ui/dr-ui/ui/library.slint:1564`](../../ui/dr-ui/ui/library.slint#L1564), [`ui/dr-ui/ui/library.slint:1597`](../../ui/dr-ui/ui/library.slint#L1597), [`ui/dr-ui/ui/library.slint:1654`](../../ui/dr-ui/ui/library.slint#L1654), [`ui/dr-ui/ui/library.slint:1661`](../../ui/dr-ui/ui/library.slint#L1661), [`ui/dr-ui/ui/library.slint:2898`](../../ui/dr-ui/ui/library.slint#L2898), [`ui/dr-ui/ui/library.slint:4501`](../../ui/dr-ui/ui/library.slint#L4501), [`ui/dr-ui/ui/library.slint:4588`](../../ui/dr-ui/ui/library.slint#L4588), [`ui/dr-ui/ui/library.slint:4647`](../../ui/dr-ui/ui/library.slint#L4647), [`ui/dr-ui/ui/library.slint:549`](../../ui/dr-ui/ui/library.slint#L549), [`ui/dr-ui/ui/library.slint:559`](../../ui/dr-ui/ui/library.slint#L559), [`ui/dr-ui/ui/library.slint:691`](../../ui/dr-ui/ui/library.slint#L691), [`ui/dr-ui/ui/settings.slint:114`](../../ui/dr-ui/ui/settings.slint#L114), [`ui/dr-ui/ui/settings.slint:656`](../../ui/dr-ui/ui/settings.slint#L656) |
+| FR-UI-4 | [`tools/traceability/src/gestures.rs:1`](../../tools/traceability/src/gestures.rs#L1), [`ui/dr-ui/src/collections_ui/controller.rs:138`](../../ui/dr-ui/src/collections_ui/controller.rs#L138), [`ui/dr-ui/src/collections_ui/controller.rs:343`](../../ui/dr-ui/src/collections_ui/controller.rs#L343), [`ui/dr-ui/src/collections_ui/controller.rs:356`](../../ui/dr-ui/src/collections_ui/controller.rs#L356), [`ui/dr-ui/src/collections_ui/controller.rs:45`](../../ui/dr-ui/src/collections_ui/controller.rs#L45), [`ui/dr-ui/src/collections_ui/controller.rs:46`](../../ui/dr-ui/src/collections_ui/controller.rs#L46), [`ui/dr-ui/src/collections_ui/controller.rs:55`](../../ui/dr-ui/src/collections_ui/controller.rs#L55), [`ui/dr-ui/src/collections_ui/controller.rs:83`](../../ui/dr-ui/src/collections_ui/controller.rs#L83), [`ui/dr-ui/src/collections_ui/drag.rs:246`](../../ui/dr-ui/src/collections_ui/drag.rs#L246), [`ui/dr-ui/src/collections_ui/drag.rs:256`](../../ui/dr-ui/src/collections_ui/drag.rs#L256), [`ui/dr-ui/src/collections_ui/press.rs:258`](../../ui/dr-ui/src/collections_ui/press.rs#L258), [`ui/dr-ui/src/collections_ui/press.rs:278`](../../ui/dr-ui/src/collections_ui/press.rs#L278), [`ui/dr-ui/src/collections_ui/press.rs:453`](../../ui/dr-ui/src/collections_ui/press.rs#L453), [`ui/dr-ui/src/collections_ui/press.rs:490`](../../ui/dr-ui/src/collections_ui/press.rs#L490), [`ui/dr-ui/src/collections_ui/press.rs:54`](../../ui/dr-ui/src/collections_ui/press.rs#L54), [`ui/dr-ui/src/collections_ui/tree_sync.rs:339`](../../ui/dr-ui/src/collections_ui/tree_sync.rs#L339), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:121`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L121), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:138`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L138), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:264`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L264), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:415`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L415), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:444`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L444), [`ui/dr-ui/src/collections_ui/wiring_grid.rs:577`](../../ui/dr-ui/src/collections_ui/wiring_grid.rs#L577), [`ui/dr-ui/src/collections_ui/wiring_tree.rs:287`](../../ui/dr-ui/src/collections_ui/wiring_tree.rs#L287), [`ui/dr-ui/src/collections_ui/wiring_tree.rs:344`](../../ui/dr-ui/src/collections_ui/wiring_tree.rs#L344), [`ui/dr-ui/src/develop/framing.rs:444`](../../ui/dr-ui/src/develop/framing.rs#L444), [`ui/dr-ui/src/develop/framing.rs:469`](../../ui/dr-ui/src/develop/framing.rs#L469), [`ui/dr-ui/src/develop/framing.rs:480`](../../ui/dr-ui/src/develop/framing.rs#L480), [`ui/dr-ui/src/develop/framing.rs:494`](../../ui/dr-ui/src/develop/framing.rs#L494), [`ui/dr-ui/src/develop/framing.rs:668`](../../ui/dr-ui/src/develop/framing.rs#L668), [`ui/dr-ui/src/develop/framing.rs:699`](../../ui/dr-ui/src/develop/framing.rs#L699), [`ui/dr-ui/src/develop/framing.rs:720`](../../ui/dr-ui/src/develop/framing.rs#L720), [`ui/dr-ui/src/develop_ui.rs:812`](../../ui/dr-ui/src/develop_ui.rs#L812), [`ui/dr-ui/src/gesture_book.rs:3`](../../ui/dr-ui/src/gesture_book.rs#L3), [`ui/dr-ui/src/gestures.rs:1`](../../ui/dr-ui/src/gestures.rs#L1), [`ui/dr-ui/src/lib.rs:1285`](../../ui/dr-ui/src/lib.rs#L1285), [`ui/dr-ui/src/lib.rs:1573`](../../ui/dr-ui/src/lib.rs#L1573), [`ui/dr-ui/src/lib.rs:2574`](../../ui/dr-ui/src/lib.rs#L2574), [`ui/dr-ui/src/lib.rs:2793`](../../ui/dr-ui/src/lib.rs#L2793), [`ui/dr-ui/src/lib.rs:2853`](../../ui/dr-ui/src/lib.rs#L2853), [`ui/dr-ui/src/lib.rs:3012`](../../ui/dr-ui/src/lib.rs#L3012), [`ui/dr-ui/src/lib.rs:3452`](../../ui/dr-ui/src/lib.rs#L3452), [`ui/dr-ui/src/lib.rs:462`](../../ui/dr-ui/src/lib.rs#L462), [`ui/dr-ui/src/lib.rs:491`](../../ui/dr-ui/src/lib.rs#L491), [`ui/dr-ui/src/library/thumbnails_fetch.rs:718`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L718), [`ui/dr-ui/src/library/thumbnails_fetch.rs:733`](../../ui/dr-ui/src/library/thumbnails_fetch.rs#L733), [`ui/dr-ui/src/library_ui/controller.rs:382`](../../ui/dr-ui/src/library_ui/controller.rs#L382), [`ui/dr-ui/src/library_ui/controller.rs:522`](../../ui/dr-ui/src/library_ui/controller.rs#L522), [`ui/dr-ui/src/library_ui/controller.rs:599`](../../ui/dr-ui/src/library_ui/controller.rs#L599), [`ui/dr-ui/src/library_ui/filter_bar.rs:444`](../../ui/dr-ui/src/library_ui/filter_bar.rs#L444), [`ui/dr-ui/src/library_ui/grid.rs:168`](../../ui/dr-ui/src/library_ui/grid.rs#L168), [`ui/dr-ui/src/library_ui/grid.rs:182`](../../ui/dr-ui/src/library_ui/grid.rs#L182), [`ui/dr-ui/src/library_ui/grid.rs:256`](../../ui/dr-ui/src/library_ui/grid.rs#L256), [`ui/dr-ui/src/library_ui/grid.rs:393`](../../ui/dr-ui/src/library_ui/grid.rs#L393), [`ui/dr-ui/src/library_ui/grid.rs:423`](../../ui/dr-ui/src/library_ui/grid.rs#L423), [`ui/dr-ui/src/settings_ui.rs:157`](../../ui/dr-ui/src/settings_ui.rs#L157), [`ui/dr-ui/src/settings_ui.rs:542`](../../ui/dr-ui/src/settings_ui.rs#L542), [`ui/dr-ui/ui/app.slint:1772`](../../ui/dr-ui/ui/app.slint#L1772), [`ui/dr-ui/ui/app.slint:1894`](../../ui/dr-ui/ui/app.slint#L1894), [`ui/dr-ui/ui/app.slint:212`](../../ui/dr-ui/ui/app.slint#L212), [`ui/dr-ui/ui/app.slint:2300`](../../ui/dr-ui/ui/app.slint#L2300), [`ui/dr-ui/ui/app.slint:2433`](../../ui/dr-ui/ui/app.slint#L2433), [`ui/dr-ui/ui/app.slint:2904`](../../ui/dr-ui/ui/app.slint#L2904), [`ui/dr-ui/ui/collections.slint:1253`](../../ui/dr-ui/ui/collections.slint#L1253), [`ui/dr-ui/ui/collections.slint:75`](../../ui/dr-ui/ui/collections.slint#L75), [`ui/dr-ui/ui/gestures.slint:1`](../../ui/dr-ui/ui/gestures.slint#L1), [`ui/dr-ui/ui/library.slint:1235`](../../ui/dr-ui/ui/library.slint#L1235), [`ui/dr-ui/ui/library.slint:1262`](../../ui/dr-ui/ui/library.slint#L1262), [`ui/dr-ui/ui/library.slint:1268`](../../ui/dr-ui/ui/library.slint#L1268), [`ui/dr-ui/ui/library.slint:1323`](../../ui/dr-ui/ui/library.slint#L1323), [`ui/dr-ui/ui/library.slint:1532`](../../ui/dr-ui/ui/library.slint#L1532), [`ui/dr-ui/ui/library.slint:1557`](../../ui/dr-ui/ui/library.slint#L1557), [`ui/dr-ui/ui/library.slint:1564`](../../ui/dr-ui/ui/library.slint#L1564), [`ui/dr-ui/ui/library.slint:1597`](../../ui/dr-ui/ui/library.slint#L1597), [`ui/dr-ui/ui/library.slint:1654`](../../ui/dr-ui/ui/library.slint#L1654), [`ui/dr-ui/ui/library.slint:1661`](../../ui/dr-ui/ui/library.slint#L1661), [`ui/dr-ui/ui/library.slint:2898`](../../ui/dr-ui/ui/library.slint#L2898), [`ui/dr-ui/ui/library.slint:4501`](../../ui/dr-ui/ui/library.slint#L4501), [`ui/dr-ui/ui/library.slint:4588`](../../ui/dr-ui/ui/library.slint#L4588), [`ui/dr-ui/ui/library.slint:4647`](../../ui/dr-ui/ui/library.slint#L4647), [`ui/dr-ui/ui/library.slint:549`](../../ui/dr-ui/ui/library.slint#L549), [`ui/dr-ui/ui/library.slint:559`](../../ui/dr-ui/ui/library.slint#L559), [`ui/dr-ui/ui/library.slint:691`](../../ui/dr-ui/ui/library.slint#L691), [`ui/dr-ui/ui/settings.slint:114`](../../ui/dr-ui/ui/settings.slint#L114), [`ui/dr-ui/ui/settings.slint:656`](../../ui/dr-ui/ui/settings.slint#L656) |
 | FR-UI-5 | [`ui/dr-ui/src/collections_ui/mod.rs:1`](../../ui/dr-ui/src/collections_ui/mod.rs#L1), [`ui/dr-ui/src/develop_ui.rs:857`](../../ui/dr-ui/src/develop_ui.rs#L857), [`ui/dr-ui/src/lib.rs:3396`](../../ui/dr-ui/src/lib.rs#L3396), [`ui/dr-ui/src/lib.rs:3603`](../../ui/dr-ui/src/lib.rs#L3603), [`ui/dr-ui/src/masks_ui.rs:1584`](../../ui/dr-ui/src/masks_ui.rs#L1584), [`ui/dr-ui/ui/app.slint:2260`](../../ui/dr-ui/ui/app.slint#L2260), [`ui/dr-ui/ui/app.slint:2300`](../../ui/dr-ui/ui/app.slint#L2300), [`ui/dr-ui/ui/collections.slint:4`](../../ui/dr-ui/ui/collections.slint#L4), [`ui/dr-ui/ui/session.slint:75`](../../ui/dr-ui/ui/session.slint#L75) |
 | FR-UI-6 | [`ui/dr-ui/ui/widgets.slint:1`](../../ui/dr-ui/ui/widgets.slint#L1) |
 | FR-UI-7 | [`core/dr-pipeline/src/descriptor.rs:195`](../../core/dr-pipeline/src/descriptor.rs#L195), [`core/dr-pipeline/src/framing.rs:395`](../../core/dr-pipeline/src/framing.rs#L395), [`core/dr-types/src/settings.rs:492`](../../core/dr-types/src/settings.rs#L492), [`ui/dr-ui/src/develop/rows.rs:118`](../../ui/dr-ui/src/develop/rows.rs#L118), [`ui/dr-ui/src/lib.rs:3221`](../../ui/dr-ui/src/lib.rs#L3221), [`ui/dr-ui/ui/adjust.slint:974`](../../ui/dr-ui/ui/adjust.slint#L974), [`ui/dr-ui/ui/app.slint:2017`](../../ui/dr-ui/ui/app.slint#L2017), [`ui/dr-ui/ui/settings.slint:681`](../../ui/dr-ui/ui/settings.slint#L681), [`ui/dr-ui/ui/toolrail.slint:89`](../../ui/dr-ui/ui/toolrail.slint#L89) |
diff --git a/ui/dr-ui/src/library/thumbnails_fetch.rs b/ui/dr-ui/src/library/thumbnails_fetch.rs
index 497f4da..e5f0282 100644
--- a/ui/dr-ui/src/library/thumbnails_fetch.rs
+++ b/ui/dr-ui/src/library/thumbnails_fetch.rs
@@ -592,6 +592,10 @@ static IN_FLIGHT: std::sync::LazyLock<InFlight> = std::sync::LazyLock::new(InFli
 pub(super) struct InFlight {
     busy: std::sync::Mutex<std::collections::HashSet<String>>,
     freed: std::sync::Condvar,
+    /// Threads parked in [`InFlight::claim`], counted under the lock so a
+    /// test can release the holder only once a waiter is really waiting.
+    #[cfg(test)]
+    waiting: std::sync::atomic::AtomicUsize,
 }
 
 impl InFlight {
@@ -609,6 +613,9 @@ impl InFlight {
                 path: path.to_string(),
             });
         }
+        #[cfg(test)]
+        self.waiting
+            .fetch_add(1, std::sync::atomic::Ordering::SeqCst);
         while busy.contains(path) {
             busy = self.freed.wait(busy).unwrap_or_else(|e| e.into_inner());
         }
@@ -901,17 +908,16 @@ mod tests {
         let first = registry.claim("shoot/one.CR2");
         assert!(first.is_some(), "an unclaimed path is claimed outright");
 
-        let (tx, rx) = std::sync::mpsc::channel();
         let waiter = {
             let registry = registry.clone();
-            std::thread::spawn(move || {
-                tx.send(()).unwrap();
-                registry.claim("shoot/one.CR2").is_some()
-            })
+            std::thread::spawn(move || registry.claim("shoot/one.CR2").is_some())
         };
-        rx.recv().unwrap();
-        // The waiter is blocked on the first claim. Not provable without a
-        // sleep, but a release that reaches it proves the wait ended there.
+        // Wait until the second claim is parked on the condvar. The count is
+        // bumped under the lock just before the wait, and the release below
+        // needs that lock, so it cannot reach the waiter any earlier.
+        while registry.waiting.load(std::sync::atomic::Ordering::SeqCst) == 0 {
+            std::thread::yield_now();
+        }
         assert!(
             !waiter.is_finished(),
             "the second claim must not return while the first is held"