Prevent database deletion

app/src/main/java/eu/faircode/email/DB.java

@@ -8,6 +8,7 @@ import android.content.SharedPreferences;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteDatabaseCorruptException;
+import android.database.sqlite.SQLiteException;
 import android.net.Uri;
 import android.text.TextUtils;
 
@@ -448,6 +449,7 @@ public abstract class DB extends RoomDatabase {
 
                     @Override
                     public void onOpen(@NonNull SupportSQLiteDatabase db) {
+                        try {
                             Map<String, String> crumb = new HashMap<>();
                             crumb.put("version", Integer.toString(db.getVersion()));
                             crumb.put("WAL", Boolean.toString(db.isWriteAheadLoggingEnabled()));
@@ -520,6 +522,27 @@ public abstract class DB extends RoomDatabase {
                                 dropTriggers(db);
 
                             createTriggers(db);
+                        } catch (SQLiteException ex) {
+                            /*
+                                at eu.faircode.email.DB$6.onOpen(DB.java:522)
+                                at eu.faircode.email.DB_Impl$1.onOpen(DB_Impl.java:171)
+                                at androidx.room.RoomOpenHelper.onOpen(RoomOpenHelper.java:136)
+                                at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.onOpen(FrameworkSQLiteOpenHelper.kt:287)
+                                at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:427)
+                                at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:316)
+                                at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.getWritableOrReadableDatabase(FrameworkSQLiteOpenHelper.kt:232)
+                                at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.innerGetDatabase(FrameworkSQLiteOpenHelper.kt:190)
+                                at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.getSupportDatabase(FrameworkSQLiteOpenHelper.kt:151)
+                                at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper.getWritableDatabase(FrameworkSQLiteOpenHelper.kt:104)
+                                at androidx.room.RoomDatabase.inTransaction(RoomDatabase.java:706)
+                             */
+                            Log.e(ex);
+                            // FrameworkSQLiteOpenHelper.innerGetDatabase will delete the database
+                            if (ex instanceof SQLiteDatabaseCorruptException)
+                                throw ex;
+                            else
+                                throw new RuntimeException("Open failed", ex);
+                        }
                     }
 
                     @Override