Fix database corruption dialog

[Alex7D3]

This avoids a SQLiteDatabaseCorruptException escaping and ensures the correct dialog is displayed rather than a generic error dialog

Purpose / Description

Accessing the collection with methods like CollectionManger::withCol or CollectionManager::getColUnsafe will attempt to open the database. When the file is corrupt this throws a SQLiteDatabaseCorruptException. In DeckPicker, withCol throws the error which is caught by a launchCatchingTask and a generic error dialog is displayed rather than the intended one.

Fixes

• Fixes Database corruption no longer shows DIALOG_LOAD_FAILED: SqliteFailure; DatabaseCorrupt; database disk image is malformed #19092

Approach

Rather than accessing the collection object directly, to avoid opening the database the collection file is accessed from CollectionManager, and BackupManager::repairCollection was changed slightly to accommodate this.

Note that the logic in repairCollection does not guarantee the dialog will always appear even if the file is still corrupt (in my testing at least). For example if return repairedFile.renameTo(colFile) succeeds and returns true, no dialog message will appear but the database could still be corrupt and prevent the decks from loading.

I am not sure what the course of action is here, maybe a stronger condition for repairCollection?

How Has This Been Tested?

I am not sure if there is a better way to do this, there probably is. I couldn't find an integration test that corrupts the database, just unit tests (if there isn't maybe this is something worth having).

I copied
Anki-Android-Backend/rsdroid-instrumented/src/androidTest/assets/initial_version_2_12_1_corrupt_regular.anki2
into
AnkiDroid/src/main/assets/.
This file is a corrupt collection used for a backend unit test. Then I modified DeckPicker::handleStartup temporarily for testing:

private fun handleStartup() {
    val context = AnkiDroidApp.instance

    val environment: AnkiDroidEnvironment =
        object : AnkiDroidEnvironment {
            private val folder = selectAnkiDroidFolder(context)

            override fun hasRequiredPermissions(): Boolean = folder.hasRequiredPermissions(context)

            override val requiredPermissions: PermissionSet
                get() = folder.permissionSet

            override fun initializeAnkiDroidFolder(): Boolean = CollectionHelper.isCurrentAnkiDroidDirAccessible(context)
        }
+   val dir = getCurrentAnkiDroidDirectory(context)
+   val targetDb = File(dir, "collection.anki2")
+   this.assets.open("initial_version_2_12_1_corrupt_regular.anki2").use { input ->
+       targetDb.outputStream().use { output ->
+           input.copyTo(output)
+       }
+   }
    viewModel.handleStartup(environment = environment)
}

and temporarily modified BackupManager::repairCollection to always return false to guarantee the dialog would appear during testing.

• Automated test suite
• Manually on Emulator
• Pixel 6 Pro API 31

Screencast.from.12-05-2025.05.57.47.AM.webm

Learning (optional, can help others)

Describe the research stage

Links to blog posts, patterns, libraries or addons used to solve this problem

Checklist

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• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[david-allison]

I feel this PR mixes two concepts:

1. launchCatchingTask does not handle a database corruption error properly
2. (maybe) repairCollection does not work if the database is corrupt

We should firstly fix the linked issue: showing the correct dialog via launchCatchingTask: anywhere in the app can throw due to a corrupt collection, and launchCatchingTask is our standard error handler which should handle this.

If repairCollection is broken, let's open a separate issue for it. This fix is likely correct, but I'd like to see a regression test here.

[Alex7D3]

Potential solution? Perhaps there is a cleaner way... but this works without making too many changes.
Also doesn't address repairing but we can deal with that in a separate issue after.

[david-allison]

Thanks! Do you want me to submit the issue with repairCollection, or do you want to submit a separate PR.

That fix looked good

[david-allison]

OK, this looks good. Needs:

• automated test (ideally with a corrupt collection, rather than just throwing the exception)
• correcting the catch block
• setting databaseCorruptFlag

[Alex7D3]

Found out there was another area that needs to handle the exception in InitialActivity. This makes sure the dialog appears on app launch (startup failure handling in DeckPicker::onCreate). Changes in CoroutineHelpers is to handle everywhere else (such as after attempting a repair).

[david-allison]

One query on the test, the rest looks good to go

You created a file, deleteOnExit() for normal handling, and deleting it manually in the teardown method seems appropriate

[Alex7D3]

One query on the test, the rest looks good to go

You created a file, deleteOnExit() for normal handling, and deleting it manually in the teardown method seems appropriate

Maybe good to add mkdirs() as well

[lukstbit]

Looks good, thanks!

[Alex7D3]

Looks good, thanks!

Thank you!