Fixed export and restore of FTS tables.

First, FTS index contents do not need to be exported. They will be recreated naturally.

Second, we can't export the secret FTS tables, or SQLite will think it's corrupted.

src/org/thoughtcrime/securesms/backup/FullBackupExporter.java

@@ -24,6 +24,7 @@ import org.thoughtcrime.securesms.database.AttachmentDatabase;
 import org.thoughtcrime.securesms.database.MmsDatabase;
 import org.thoughtcrime.securesms.database.MmsSmsColumns;
 import org.thoughtcrime.securesms.database.OneTimePreKeyDatabase;
+import org.thoughtcrime.securesms.database.SearchDatabase;
 import org.thoughtcrime.securesms.database.SessionDatabase;
 import org.thoughtcrime.securesms.database.SignedPreKeyDatabase;
 import org.thoughtcrime.securesms.database.SmsDatabase;
@@ -78,7 +79,9 @@ public class FullBackupExporter extends FullBackupBase {
         count = exportTable(table, input, outputStream, null, cursor -> exportAttachment(attachmentSecret, cursor, outputStream), count);
       } else if (!table.equals(SignedPreKeyDatabase.TABLE_NAME)       &&
                  !table.equals(OneTimePreKeyDatabase.TABLE_NAME)      &&
-                 !table.equals(SessionDatabase.TABLE_NAME))
+                 !table.equals(SessionDatabase.TABLE_NAME)            &&
+                 !table.startsWith(SearchDatabase.SMS_FTS_TABLE_NAME) &&
+                 !table.startsWith(SearchDatabase.MMS_FTS_TABLE_NAME))
       {
         count = exportTable(table, input, outputStream, null, null, count);
       }
@@ -111,17 +114,20 @@ public class FullBackupExporter extends FullBackupBase {
         String type = cursor.getString(2);
 
         if (sql != null) {
+
+          boolean isSmsFtsSecretTable = name != null && !name.equals(SearchDatabase.SMS_FTS_TABLE_NAME) && name.startsWith(SearchDatabase.SMS_FTS_TABLE_NAME);
+          boolean isMmsFtsSecretTable = name != null && !name.equals(SearchDatabase.MMS_FTS_TABLE_NAME) && name.startsWith(SearchDatabase.MMS_FTS_TABLE_NAME);
+
+          if (!isSmsFtsSecretTable && !isMmsFtsSecretTable) {
             if ("table".equals(type)) {
-            outputStream.write(BackupProtos.SqlStatement.newBuilder().setStatement("DROP TABLE IF EXISTS " + name).build());
               tables.add(name);
-          } else if ("index".equals(type)) {
-            outputStream.write(BackupProtos.SqlStatement.newBuilder().setStatement("DROP INDEX IF EXISTS " + name).build());
             }
 
             outputStream.write(BackupProtos.SqlStatement.newBuilder().setStatement(cursor.getString(0)).build());
           }
         }
       }
+    }
 
     return tables;
   }

src/org/thoughtcrime/securesms/backup/FullBackupImporter.java

@@ -7,6 +7,7 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.database.Cursor;
 import android.support.annotation.NonNull;
+import android.util.Log;
 import android.util.Pair;
 
 import net.sqlcipher.database.SQLiteDatabase;
@@ -21,6 +22,7 @@ import org.thoughtcrime.securesms.crypto.AttachmentSecret;
 import org.thoughtcrime.securesms.crypto.ModernEncryptingPartOutputStream;
 import org.thoughtcrime.securesms.database.Address;
 import org.thoughtcrime.securesms.database.AttachmentDatabase;
+import org.thoughtcrime.securesms.database.SearchDatabase;
 import org.thoughtcrime.securesms.profiles.AvatarHelper;
 import org.thoughtcrime.securesms.util.Conversions;
 import org.thoughtcrime.securesms.util.Util;
@@ -37,6 +39,7 @@ import java.security.InvalidAlgorithmParameterException;
 import java.security.InvalidKeyException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -90,6 +93,14 @@ public class FullBackupImporter extends FullBackupBase {
   }
 
   private static void processStatement(@NonNull SQLiteDatabase db, SqlStatement statement) {
+    boolean isForSmsFtsSecretTable = statement.getStatement().contains(SearchDatabase.SMS_FTS_TABLE_NAME + "_");
+    boolean isForMmsFtsSecretTable = statement.getStatement().contains(SearchDatabase.MMS_FTS_TABLE_NAME + "_");
+
+    if (isForSmsFtsSecretTable || isForMmsFtsSecretTable) {
+      Log.i(TAG, "Ignoring import for statement: " + statement.getStatement());
+      return;
+    }
+
     List<Object> parameters = new LinkedList<>();
 
     for (SqlStatement.SqlParameter parameter : statement.getParametersList()) {