* Change return value of `SyncChaptersWithSource.await()`
`updatedToAdd.subtract(reAdded).toList()` never worked as at this point `updatedToAdd` contained ids from db where `reAdded` had default one. Was the same case before the rewrite.
Removed `toDelete` from return value as it was not being used anywhere
* Add doc string
* Use HashSet
Co-authored-by: stevenyomi <95685115+stevenyomi@users.noreply.github.com>
Co-authored-by: stevenyomi <95685115+stevenyomi@users.noreply.github.com>
(cherry picked from commit 11f640cfee427b8912cdc43fc3efc61e0f774aa7)
# Conflicts:
# app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateService.kt
# app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaPresenter.kt
0b1afc1b94