Show failed migrations instead of waiting on them forever

CHANGELOG.md

@@ -44,6 +44,7 @@ The format is a modified version of [Keep a Changelog](https://keepachangelog.co
 - Fixed the app closing when WebView's page process crashed ([@AntsyLich](https://github.com/AntsyLich))
 - Fixed installing or updating an extension sometimes cancelling the install of another one ([@AntsyLich](https://github.com/AntsyLich))
 - Fixed updating from v0.20.x taking up to hours on libraries with many duplicate entries ([@AntsyLich](https://github.com/AntsyLich))
+- Fixed the app staying on the updating screen for good when updating its data failed, it now shows what went wrong, and updating failing on leftover data of deleted entries ([@AntsyLich](https://github.com/AntsyLich))
 
 ## [v0.21.0] - 2026-10-12
 ### Added

app/src/main/java/eu/kanade/tachiyomi/ui/main/MainActivity.kt

@@ -179,6 +179,9 @@ class MainActivity : BaseActivity() {
             Migrator.awaitAndRelease()
             isAppMigrating.value = false
         }
+        // Uncaught on purpose: a failed database migration otherwise leaves the migrating screen up for good,
+        // while the crash screen tells what went wrong and lets the logs be shared
+        lifecycleScope.launch { databaseRepository.awaitOpen() }
 
         // Do not let the launcher create a new activity http://stackoverflow.com/questions/16283079
         if (!isTaskRoot) {

app/src/main/java/mihon/core/migration/MigrationJobFactory.kt

@@ -1,9 +1,11 @@
 package mihon.core.migration
 
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.async
+import logcat.LogPriority
 import tachiyomi.core.common.util.system.logcat
 
 class MigrationJobFactory(
@@ -20,7 +22,18 @@ class MigrationJobFactory(
                     }
                     async {
                         val prev = acc.await()
-                        migration(migrationContext) || prev
+                        // A failure would cancel the rest of the chain and leave the app waiting on it for good
+                        val ran = try {
+                            migration(migrationContext)
+                        } catch (e: CancellationException) {
+                            throw e
+                        } catch (e: Exception) {
+                            logcat(LogPriority.ERROR, e) {
+                                "Migration failed: { name = ${migration::class.simpleName}, version = ${migration.version} }"
+                            }
+                            false
+                        }
+                        ran || prev
                     }
                 } else {
                     logcat {

data/src/main/java/mihon/data/database/DatabaseRepositoryImpl.kt

@@ -1,16 +1,29 @@
 package mihon.data.database
 
+import app.cash.sqldelight.db.QueryResult
+import app.cash.sqldelight.db.SqlDriver
 import dev.zacsweers.metro.AppScope
 import dev.zacsweers.metro.ContributesBinding
 import dev.zacsweers.metro.Inject
 import dev.zacsweers.metro.SingleIn
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.withContext
 import mihon.domain.database.repository.DatabaseRepository
 
 @Inject
 @SingleIn(AppScope::class)
 @ContributesBinding(AppScope::class)
-class DatabaseRepositoryImpl : DatabaseRepository {
+class DatabaseRepositoryImpl(
+    // Lazy since the driver reports its migration state here
+    private val driver: Lazy<SqlDriver>,
+) : DatabaseRepository {
 
     override val isMigrating = MutableStateFlow(false)
+
+    override suspend fun awaitOpen() {
+        withContext(Dispatchers.IO) {
+            driver.value.executeQuery(null, "SELECT 1", { QueryResult.Value(Unit) }, 0).await()
+        }
+    }
 }

data/src/main/sqldelight/tachiyomi/migrations/17.sqm

@@ -4,6 +4,19 @@ import kotlin.String;
 import kotlin.collections.List;
 import kotlinx.serialization.json.JsonObject;
 
+-- ---------------------------------------------------------------------------------------------------------
+-- orphans
+-- ---------------------------------------------------------------------------------------------------------
+
+-- Rows pointing at an entry, chapter or category that no longer exists were written while foreign keys weren't
+-- enforced. Nothing can reach them, and copied over they'd fail the foreign key check that ends the migration.
+DELETE FROM chapters WHERE manga_id NOT IN (SELECT _id FROM mangas);
+DELETE FROM history WHERE chapter_id NOT IN (SELECT _id FROM chapters);
+DELETE FROM mangas_categories
+WHERE manga_id NOT IN (SELECT _id FROM mangas) OR category_id NOT IN (SELECT _id FROM categories);
+DELETE FROM manga_sync WHERE manga_id NOT IN (SELECT _id FROM mangas);
+DELETE FROM excluded_scanlators WHERE manga_id NOT IN (SELECT _id FROM mangas);
+
 -- ---------------------------------------------------------------------------------------------------------
 -- table - manga
 -- ---------------------------------------------------------------------------------------------------------

domain/src/main/java/mihon/domain/database/repository/DatabaseRepository.kt

@@ -9,4 +9,9 @@ interface DatabaseRepository {
      * app update.
      */
     val isMigrating: StateFlow<Boolean>
+
+    /**
+     * Opens the database, migrating it if needed, and throws what made the migration fail.
+     */
+    suspend fun awaitOpen()
 }