Add a intermediate migration to fix old installations

appinfo/info.xml

@@ -14,7 +14,7 @@
 		More information is available in the Activity documentation.
 	</description>
 
-	<version>2.8.1</version>
+	<version>2.8.2</version>
 	<licence>agpl</licence>
 	<author>Frank Karlitschek</author>
 	<author>Joas Schilling</author>

lib/Migration/Version2007Date20181107114613.php

@@ -0,0 +1,68 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018, Joas Schilling <coding@schilljs.com>
+ *
+ * @author Joas Schilling <coding@schilljs.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Activity\Migration;
+
+use Closure;
+use Doctrine\DBAL\Types\Type;
+use OCP\DB\ISchemaWrapper;
+use OCP\Migration\SimpleMigrationStep;
+use OCP\Migration\IOutput;
+
+class Version2007Date20181107114613 extends SimpleMigrationStep {
+	/**
+	 * @param IOutput $output
+	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+	 * @param array $options
+	 * @return null|ISchemaWrapper
+	 */
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options) {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$table = $schema->getTable('activity');
+
+		if (!$table->hasColumn('object_type')) {
+			$table->addColumn('object_type', Type::STRING, [
+				'notnull' => false,
+				'length' => 255,
+			]);
+			$table->addColumn('object_id', Type::BIGINT, [
+				'notnull' => true,
+				'length' => 20,
+				'default' => 0,
+			]);
+		}
+
+		if (!$table->hasIndex('activity_time')) {
+			$table->addIndex(['timestamp'], 'activity_time');
+		}
+
+		if (!$table->hasIndex('activity_object')) {
+			$table->addIndex(['object_type', 'object_id'], 'activity_object');
+		}
+
+		return $schema;
+	}
+}