After destructive Room migration, random application grid items inserted to home screen

[JackEblan]

Bug Description

After a destructive Room database migration, random application grid items are being inserted to the home screen, even though firstLaunch is already false in userData.

Root Cause

When Room is destroyed via destructive migration:

1. All database tables are cleared (including ApplicationInfoGridItemEntity)
2. SyncDataUseCase.invoke() runs on app restart
3. updateEblanApplicationInfos() is called with empty oldSyncEblanApplicationInfos
4. In addNewApplicationsToHomeScreen(), the logic compares:
   • oldAddNewEblanApplicationInfos = EMPTY (no apps in old database)
   • newAddNewEblanApplicationInfos = ALL non-system apps from system
   • addNewEblanApplicationInfos = newAddNewEblanApplicationInfos - oldAddNewEblanApplicationInfos.toSet() → ALL apps are treated as NEW
5. All non-system apps get inserted as random grid items to the home screen

Solution

When performing a destructive migration of Room, ensure that addNewAppsToHomeScreen is set to false in the UserData migration so that apps are not treated as new when the database is rebuilt from scratch.

Alternatively, detect destructive migration by checking if grid items table is empty before calling addNewApplicationsToHomeScreen().

Code Location

• domain/use-case/src/main/kotlin/com/eblan/launcher/domain/usecase/launcherapps/SyncDataUseCase.kt - updateEblanApplicationInfos() method
• domain/use-case/src/main/kotlin/com/eblan/launcher/domain/usecase/launcherapps/LauncherAppsUtil.kt - addNewApplicationsToHomeScreen() function
• data/room/src/main/kotlin/com/eblan/launcher/data/room/di/RoomModule.kt - .fallbackToDestructiveMigrationFrom() configuration

[synthead]

F-Droid installed 0.8.8-alpha, which removed all my browser shortcuts and widgets, and placed icons for everything in the app drawer onto my home screen. @JackEblan, is this the "destructive Room migration" you're referring to?

[TriflingToad]

Glad you know all the fancy words to use because I was gonna make a bug report of "my apps are different ☹️" and attach a photo lol