diff --git a/.github/workflows/oci.yml b/.github/workflows/oci.yml
new file mode 100644
index 0000000000000000000000000000000000000000..5b545461e5d2026532a0ac9c31b297a65cc1d529
--- /dev/null
+++ b/.github/workflows/oci.yml
@@ -0,0 +1,56 @@
+name: PHPUnit
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - stable*
+
+jobs:
+  phpunit-oci8:
+    runs-on: ubuntu-latest
+
+    strategy:
+      # do not stop on another job's failure
+      fail-fast: false
+      matrix:
+        php-versions: [ '7.4' ]
+        databases: [ 'oci' ]
+
+    name: php${{ matrix.php-versions }}-${{ matrix.databases }}
+
+    services:
+      oracle:
+        image: deepdiver/docker-oracle-xe-11g # "wnameless/oracle-xe-11g-r2"
+        ports:
+          - "1521:1521"
+
+    steps:
+      - name: Checkout server
+        uses: actions/checkout@v2
+
+      - name: Checkout submodules
+        shell: bash
+        run: |
+          auth_header="$(git config --local --get http.https://github.com/.extraheader)"
+          git submodule sync --recursive
+          git -c "http.extraheader=$auth_header" -c protocol.version=2 submodule update --init --force --recursive --depth=1
+
+      - name: Set up php ${{ matrix.php-versions }}
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+          extensions: mbstring, iconv, fileinfo, intl, sqlite, pdo_sqlite, oci8
+          tools: phpunit:8.5.2
+          coverage: none
+
+      - name: Set up Nextcloud
+        run: |
+          mkdir data
+          ./occ maintenance:install --verbose --database=oci --database-name=XE --database-host=127.0.0.1 --database-port=1521 --database-user=autotest --database-pass=owncloud --admin-user admin --admin-pass admin
+          php -f index.php
+
+      - name: PHPUnit
+        working-directory: tests
+        run: phpunit --configuration phpunit-autotest.xml --group DB,SLOWDB
diff --git a/apps/dav/appinfo/info.xml b/apps/dav/appinfo/info.xml
index 53825f55072084da6adf317852420f631a6869eb..d9a5761230a64ace28f2b4b50334fa338e653be3 100644
--- a/apps/dav/appinfo/info.xml
+++ b/apps/dav/appinfo/info.xml
@@ -5,7 +5,7 @@
 	<name>WebDAV</name>
 	<summary>WebDAV endpoint</summary>
 	<description>WebDAV endpoint</description>
-	<version>1.17.0</version>
+	<version>1.17.1</version>
 	<licence>agpl</licence>
 	<author>owncloud.org</author>
 	<namespace>DAV</namespace>
diff --git a/apps/dav/composer/composer/autoload_classmap.php b/apps/dav/composer/composer/autoload_classmap.php
index aaa5e82da04554b9c9efbed1865b0367d0c4e23b..e0684f0c793d847358d6960b1bf3f4532c5256d0 100644
--- a/apps/dav/composer/composer/autoload_classmap.php
+++ b/apps/dav/composer/composer/autoload_classmap.php
@@ -230,6 +230,7 @@ return array(
     'OCA\\DAV\\Migration\\Version1011Date20190725113607' => $baseDir . '/../lib/Migration/Version1011Date20190725113607.php',
     'OCA\\DAV\\Migration\\Version1011Date20190806104428' => $baseDir . '/../lib/Migration/Version1011Date20190806104428.php',
     'OCA\\DAV\\Migration\\Version1012Date20190808122342' => $baseDir . '/../lib/Migration/Version1012Date20190808122342.php',
+    'OCA\\DAV\\Migration\\Version1016Date20201109085907' => $baseDir . '/../lib/Migration/Version1016Date20201109085907.php',
     'OCA\\DAV\\Provisioning\\Apple\\AppleProvisioningNode' => $baseDir . '/../lib/Provisioning/Apple/AppleProvisioningNode.php',
     'OCA\\DAV\\Provisioning\\Apple\\AppleProvisioningPlugin' => $baseDir . '/../lib/Provisioning/Apple/AppleProvisioningPlugin.php',
     'OCA\\DAV\\RootCollection' => $baseDir . '/../lib/RootCollection.php',
diff --git a/apps/dav/composer/composer/autoload_static.php b/apps/dav/composer/composer/autoload_static.php
index 0dc34f5a3172b0ee2222fc50dc9655f580f8d939..32b5e03a3fad7a3f0a8bf9993f6f3061452d2113 100644
--- a/apps/dav/composer/composer/autoload_static.php
+++ b/apps/dav/composer/composer/autoload_static.php
@@ -245,6 +245,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Migration\\Version1011Date20190725113607' => __DIR__ . '/..' . '/../lib/Migration/Version1011Date20190725113607.php',
         'OCA\\DAV\\Migration\\Version1011Date20190806104428' => __DIR__ . '/..' . '/../lib/Migration/Version1011Date20190806104428.php',
         'OCA\\DAV\\Migration\\Version1012Date20190808122342' => __DIR__ . '/..' . '/../lib/Migration/Version1012Date20190808122342.php',
+        'OCA\\DAV\\Migration\\Version1016Date20201109085907' => __DIR__ . '/..' . '/../lib/Migration/Version1016Date20201109085907.php',
         'OCA\\DAV\\Provisioning\\Apple\\AppleProvisioningNode' => __DIR__ . '/..' . '/../lib/Provisioning/Apple/AppleProvisioningNode.php',
         'OCA\\DAV\\Provisioning\\Apple\\AppleProvisioningPlugin' => __DIR__ . '/..' . '/../lib/Provisioning/Apple/AppleProvisioningPlugin.php',
         'OCA\\DAV\\RootCollection' => __DIR__ . '/..' . '/../lib/RootCollection.php',
diff --git a/apps/dav/lib/CalDAV/CalDavBackend.php b/apps/dav/lib/CalDAV/CalDavBackend.php
index 4ff51a5f52745a5cde28a523b58e70a74f35cb25..84294971b417a52bbd0150ab430dee975ea9baf7 100644
--- a/apps/dav/lib/CalDAV/CalDavBackend.php
+++ b/apps/dav/lib/CalDAV/CalDavBackend.php
@@ -242,8 +242,13 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 		$principalUri = $this->convertPrincipal($principalUri, true);
 		$query = $this->db->getQueryBuilder();
 		$query->select($query->func()->count('*'))
-			->from('calendars')
-			->where($query->expr()->eq('principaluri', $query->createNamedParameter($principalUri)));
+			->from('calendars');
+
+		if ($principalUri === '') {
+			$query->where($query->expr()->emptyString('principaluri'));
+		} else {
+			$query->where($query->expr()->eq('principaluri', $query->createNamedParameter($principalUri)));
+		}
 
 		if ($excludeBirthday) {
 			$query->andWhere($query->expr()->neq('uri', $query->createNamedParameter(BirthdayService::BIRTHDAY_CALENDAR_URI)));
@@ -293,13 +298,21 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 
 		// Making fields a comma-delimited list
 		$query = $this->db->getQueryBuilder();
-		$query->select($fields)->from('calendars')
-				->where($query->expr()->eq('principaluri', $query->createNamedParameter($principalUri)))
-				->orderBy('calendarorder', 'ASC');
-		$stmt = $query->execute();
+		$query->select($fields)
+			->from('calendars')
+			->orderBy('calendarorder', 'ASC');
+
+		if ($principalUri === '') {
+			$query->where($query->expr()->emptyString('principaluri'));
+		} else {
+			$query->where($query->expr()->eq('principaluri', $query->createNamedParameter($principalUri)));
+		}
+
+		$result = $query->execute();
 
 		$calendars = [];
-		while ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+		while ($row = $result->fetch()) {
+			$row['principaluri'] = (string) $row['principaluri'];
 			$components = [];
 			if ($row['components']) {
 				$components = explode(',',$row['components']);
@@ -326,8 +339,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 				$calendars[$calendar['id']] = $calendar;
 			}
 		}
-
-		$stmt->closeCursor();
+		$result->closeCursor();
 
 		// query for shared calendars
 		$principals = $this->principalBackend->getGroupMembership($principalUriOriginal, true);
@@ -347,17 +359,19 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 		$fields[] = 'a.transparent';
 		$fields[] = 's.access';
 		$query = $this->db->getQueryBuilder();
-		$result = $query->select($fields)
+		$query->select($fields)
 			->from('dav_shares', 's')
 			->join('s', 'calendars', 'a', $query->expr()->eq('s.resourceid', 'a.id'))
 			->where($query->expr()->in('s.principaluri', $query->createParameter('principaluri')))
 			->andWhere($query->expr()->eq('s.type', $query->createParameter('type')))
 			->setParameter('type', 'calendar')
-			->setParameter('principaluri', $principals, \Doctrine\DBAL\Connection::PARAM_STR_ARRAY)
-			->execute();
+			->setParameter('principaluri', $principals, \Doctrine\DBAL\Connection::PARAM_STR_ARRAY);
+
+		$result	= $query->execute();
 
 		$readOnlyPropertyName = '{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}read-only';
 		while ($row = $result->fetch()) {
+			$row['principaluri'] = (string) $row['principaluri'];
 			if ($row['principaluri'] === $principalUri) {
 				continue;
 			}
@@ -428,6 +442,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 		$stmt = $query->execute();
 		$calendars = [];
 		while ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+			$row['principaluri'] = (string) $row['principaluri'];
 			$components = [];
 			if ($row['components']) {
 				$components = explode(',',$row['components']);
@@ -497,6 +512,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			->execute();
 
 		while ($row = $result->fetch()) {
+			$row['principaluri'] = (string) $row['principaluri'];
 			list(, $name) = Uri\split($row['principaluri']);
 			$row['displayname'] = $row['displayname'] . "($name)";
 			$components = [];
@@ -563,6 +579,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			throw new NotFound('Node with name \'' . $uri . '\' could not be found');
 		}
 
+		$row['principaluri'] = (string) $row['principaluri'];
 		list(, $name) = Uri\split($row['principaluri']);
 		$row['displayname'] = $row['displayname'] . ' ' . "($name)";
 		$components = [];
@@ -619,6 +636,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			return null;
 		}
 
+		$row['principaluri'] = (string) $row['principaluri'];
 		$components = [];
 		if ($row['components']) {
 			$components = explode(',',$row['components']);
@@ -669,6 +687,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			return null;
 		}
 
+		$row['principaluri'] = (string) $row['principaluri'];
 		$components = [];
 		if ($row['components']) {
 			$components = explode(',',$row['components']);
@@ -718,6 +737,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			return null;
 		}
 
+		$row['principaluri'] = (string) $row['principaluri'];
 		$subscription = [
 			'id' => $row['id'],
 			'uri' => $row['uri'],
@@ -965,6 +985,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 				'classification' => (int)$row['classification']
 			];
 		}
+		$stmt->closeCursor();
 
 		return $result;
 	}
@@ -995,6 +1016,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			->andWhere($query->expr()->eq('calendartype', $query->createNamedParameter($calendarType)));
 		$stmt = $query->execute();
 		$row = $stmt->fetch(\PDO::FETCH_ASSOC);
+		$stmt->closeCursor();
 
 		if (!$row) {
 			return null;
diff --git a/apps/dav/lib/Migration/Version1012Date20190808122342.php b/apps/dav/lib/Migration/Version1012Date20190808122342.php
index 7aa51a224ec0575ddb78ff1ffa5faace9a5b67a4..51929d1a2f5dc007831419d6cdb93a6f81ae4241 100644
--- a/apps/dav/lib/Migration/Version1012Date20190808122342.php
+++ b/apps/dav/lib/Migration/Version1012Date20190808122342.php
@@ -69,7 +69,7 @@ class Version1012Date20190808122342 extends SimpleMigrationStep {
 				'length' => 11,
 			]);
 			$table->addColumn('is_recurring', Types::SMALLINT, [
-				'notnull' => true,
+				'notnull' => false,
 				'length' => 1,
 			]);
 			$table->addColumn('uid', Types::STRING, [
diff --git a/apps/dav/lib/Migration/Version1016Date20201109085907.php b/apps/dav/lib/Migration/Version1016Date20201109085907.php
new file mode 100644
index 0000000000000000000000000000000000000000..fd8996d5e2241dfb9c332851a96f47215a23509a
--- /dev/null
+++ b/apps/dav/lib/Migration/Version1016Date20201109085907.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020 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\DAV\Migration;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+class Version1016Date20201109085907 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): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$result = $this->ensureColumnIsNullable($schema, 'calendar_reminders', 'is_recurring');
+
+		return $result ? $schema : null;
+	}
+
+	protected function ensureColumnIsNullable(ISchemaWrapper $schema, string $tableName, string $columnName): bool {
+		$table = $schema->getTable($tableName);
+		$column = $table->getColumn($columnName);
+
+		if ($column->getNotnull()) {
+			$column->setNotnull(false);
+			return true;
+		}
+
+		return false;
+	}
+}
diff --git a/apps/dav/tests/unit/DAV/CustomPropertiesBackendTest.php b/apps/dav/tests/unit/DAV/CustomPropertiesBackendTest.php
index 2633ccf544fe0142b6597f7809fd28dc6d8c5697..86a88b3ccdccb78b4a115d80c3eea7f3a925ea65 100644
--- a/apps/dav/tests/unit/DAV/CustomPropertiesBackendTest.php
+++ b/apps/dav/tests/unit/DAV/CustomPropertiesBackendTest.php
@@ -110,10 +110,13 @@ class CustomPropertiesBackendTest extends TestCase {
 			->where($query->expr()->eq('userid', $query->createNamedParameter($user)))
 			->where($query->expr()->eq('propertypath', $query->createNamedParameter($this->formatPath($path))));
 
-
 		$result = $query->execute();
-		$data = $result->fetchAll(\PDO::FETCH_KEY_PAIR);
+		$data = [];
+		while ($row = $result->fetch()) {
+			$data[$row['propertyname']] = $row['propertyvalue'];
+		}
 		$result->closeCursor();
+
 		return $data;
 	}
 
diff --git a/apps/federatedfilesharing/lib/Migration/Version1010Date20200630191755.php b/apps/federatedfilesharing/lib/Migration/Version1010Date20200630191755.php
index 53348d8f86d632ee1d72c109fa45d80d15894085..bf0d0f8eecdfea17e51c10589a5afa5a7d44ff5c 100644
--- a/apps/federatedfilesharing/lib/Migration/Version1010Date20200630191755.php
+++ b/apps/federatedfilesharing/lib/Migration/Version1010Date20200630191755.php
@@ -52,7 +52,8 @@ class Version1010Date20200630191755 extends SimpleMigrationStep {
 				'notnull' => true,
 				'length' => 4,
 			]);
-			$table->addUniqueIndex(['share_id'], 'share_id_index');
+			$table->setPrimaryKey(['share_id'], 'federated_res_pk');
+//			$table->addUniqueIndex(['share_id'], 'share_id_index');
 		}
 		return $schema;
 	}
diff --git a/apps/oauth2/tests/Db/ClientMapperTest.php b/apps/oauth2/tests/Db/ClientMapperTest.php
index ad1612da6b429996d830c166769d769085f87752..e4a71fc104057478f5cb3b0d5bf044b18b9012d4 100644
--- a/apps/oauth2/tests/Db/ClientMapperTest.php
+++ b/apps/oauth2/tests/Db/ClientMapperTest.php
@@ -40,6 +40,13 @@ class ClientMapperTest extends TestCase {
 		$this->clientMapper = new ClientMapper(\OC::$server->getDatabaseConnection());
 	}
 
+	protected function tearDown(): void {
+		$query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
+		$query->delete('oauth2_clients')->execute();
+
+		parent::tearDown();
+	}
+
 	public function testGetByIdentifier() {
 		$client = new Client();
 		$client->setClientIdentifier('MyAwesomeClientIdentifier');
@@ -51,7 +58,6 @@ class ClientMapperTest extends TestCase {
 		$this->assertEquals($client, $this->clientMapper->getByIdentifier('MyAwesomeClientIdentifier'));
 	}
 
-	
 	public function testGetByIdentifierNotExisting() {
 		$this->expectException(\OCA\OAuth2\Exceptions\ClientNotFoundException::class);
 
@@ -69,7 +75,6 @@ class ClientMapperTest extends TestCase {
 		$this->assertEquals($client, $this->clientMapper->getByUid($client->getId()));
 	}
 
-	
 	public function testGetByUidNotExisting() {
 		$this->expectException(\OCA\OAuth2\Exceptions\ClientNotFoundException::class);
 
diff --git a/apps/settings/lib/Controller/CheckSetupController.php b/apps/settings/lib/Controller/CheckSetupController.php
index 0f9dd84febbff61dd5b7ffd8639373f4343e19db..6984b0f5aea6d215de5411192ec995a319c43b3e 100644
--- a/apps/settings/lib/Controller/CheckSetupController.php
+++ b/apps/settings/lib/Controller/CheckSetupController.php
@@ -49,6 +49,7 @@ use OC\AppFramework\Http;
 use OC\DB\Connection;
 use OC\DB\MissingColumnInformation;
 use OC\DB\MissingIndexInformation;
+use OC\DB\MissingPrimaryKeyInformation;
 use OC\DB\SchemaWrapper;
 use OC\IntegrityCheck\Checker;
 use OC\Lock\NoopLockingProvider;
@@ -452,6 +453,15 @@ Raw output
 		return $indexInfo->getListOfMissingIndexes();
 	}
 
+	protected function hasMissingPrimaryKeys(): array {
+		$info = new MissingPrimaryKeyInformation();
+		// Dispatch event so apps can also hint for pending index updates if needed
+		$event = new GenericEvent($info);
+		$this->dispatcher->dispatch(IDBConnection::CHECK_MISSING_PRIMARY_KEYS_EVENT, $event);
+
+		return $info->getListOfMissingPrimaryKeys();
+	}
+
 	protected function hasMissingColumns(): array {
 		$indexInfo = new MissingColumnInformation();
 		// Dispatch event so apps can also hint for pending index updates if needed
@@ -722,6 +732,7 @@ Raw output
 				'phpOpcacheDocumentation' => $this->urlGenerator->linkToDocs('admin-php-opcache'),
 				'isSettimelimitAvailable' => $this->isSettimelimitAvailable(),
 				'hasFreeTypeSupport' => $this->hasFreeTypeSupport(),
+				'missingPrimaryKeys' => $this->hasMissingPrimaryKeys(),
 				'missingIndexes' => $this->hasMissingIndexes(),
 				'missingColumns' => $this->hasMissingColumns(),
 				'isSqliteUsed' => $this->isSqliteUsed(),
diff --git a/apps/settings/tests/Controller/CheckSetupControllerTest.php b/apps/settings/tests/Controller/CheckSetupControllerTest.php
index dbc3fc7d0dbcd0c491e2af215124a021e476c7fc..43ec984041c8a96ab861711e18cd39351b95e6b1 100644
--- a/apps/settings/tests/Controller/CheckSetupControllerTest.php
+++ b/apps/settings/tests/Controller/CheckSetupControllerTest.php
@@ -165,6 +165,7 @@ class CheckSetupControllerTest extends TestCase {
 				'isOpcacheProperlySetup',
 				'hasFreeTypeSupport',
 				'hasMissingIndexes',
+				'hasMissingPrimaryKeys',
 				'isSqliteUsed',
 				'isPHPMailerUsed',
 				'hasOpcacheLoaded',
@@ -448,6 +449,9 @@ class CheckSetupControllerTest extends TestCase {
 		$this->checkSetupController
 			->method('hasMissingIndexes')
 			->willReturn([]);
+		$this->checkSetupController
+			->method('hasMissingPrimaryKeys')
+			->willReturn([]);
 		$this->checkSetupController
 			->method('isSqliteUsed')
 			->willReturn(false);
@@ -587,6 +591,7 @@ class CheckSetupControllerTest extends TestCase {
 				'isSqliteUsed' => false,
 				'databaseConversionDocumentation' => 'http://docs.example.org/server/go.php?to=admin-db-conversion',
 				'missingIndexes' => [],
+				'missingPrimaryKeys' => [],
 				'missingColumns' => [],
 				'isMemoryLimitSufficient' => true,
 				'appDirsWithDifferentOwner' => [],
diff --git a/build/psalm-baseline.xml b/build/psalm-baseline.xml
index b4b164f7835c6ab9435945e8939f4249cb8f80d5..e033bab7b37ee4e8cb6634442b95ac3a86a0cbe9 100644
--- a/build/psalm-baseline.xml
+++ b/build/psalm-baseline.xml
@@ -1700,6 +1700,7 @@
   <file src="apps/files_sharing/lib/Controller/ShareController.php">
     <InvalidArgument occurrences="2">
       <code>$files_list</code>
+      <code>'Share has no read permission'</code>
     </InvalidArgument>
     <InvalidScalarArgument occurrences="3">
       <code>$freeSpace</code>
@@ -2031,9 +2032,10 @@
     </UndefinedInterfaceMethod>
   </file>
   <file src="apps/settings/lib/Controller/CheckSetupController.php">
-    <InvalidArgument occurrences="2">
+    <InvalidArgument occurrences="3">
       <code>IDBConnection::CHECK_MISSING_COLUMNS_EVENT</code>
       <code>IDBConnection::CHECK_MISSING_INDEXES_EVENT</code>
+      <code>IDBConnection::CHECK_MISSING_PRIMARY_KEYS_EVENT</code>
     </InvalidArgument>
     <InvalidOperand occurrences="1">
       <code>$lastCronRun</code>
@@ -2049,7 +2051,8 @@
       <code>$lastCronRun</code>
       <code>0</code>
     </InvalidScalarArgument>
-    <TooManyArguments occurrences="2">
+    <TooManyArguments occurrences="3">
+      <code>dispatch</code>
       <code>dispatch</code>
       <code>dispatch</code>
     </TooManyArguments>
@@ -2728,6 +2731,14 @@
       <code>dispatch</code>
     </TooManyArguments>
   </file>
+  <file src="core/Command/Db/AddMissingPrimaryKeys.php">
+    <InvalidArgument occurrences="1">
+      <code>IDBConnection::ADD_MISSING_PRIMARY_KEYS_EVENT</code>
+    </InvalidArgument>
+    <TooManyArguments occurrences="1">
+      <code>dispatch</code>
+    </TooManyArguments>
+  </file>
   <file src="core/Command/Db/ConvertType.php">
     <InvalidArgument occurrences="2">
       <code>$chunk * $chunkSize</code>
@@ -3506,7 +3517,9 @@
     <InvalidScalarArgument occurrences="1">
       <code>$e-&gt;getCode()</code>
     </InvalidScalarArgument>
-    <LessSpecificImplementedReturnType occurrences="1"/>
+    <LessSpecificImplementedReturnType occurrences="1">
+      <code>\Doctrine\DBAL\Driver\Statement</code>
+    </LessSpecificImplementedReturnType>
     <ParamNameMismatch occurrences="1">
       <code>$statement</code>
     </ParamNameMismatch>
@@ -3599,7 +3612,9 @@
     </NullableReturnStatement>
   </file>
   <file src="lib/private/DB/ReconnectWrapper.php">
-    <InternalMethod occurrences="1"/>
+    <InternalMethod occurrences="1">
+      <code>parent::__construct($params, $driver, $config, $eventManager)</code>
+    </InternalMethod>
   </file>
   <file src="lib/private/DateTimeFormatter.php">
     <FalsableReturnStatement occurrences="1"/>
@@ -5284,7 +5299,6 @@
       <code>$appName</code>
       <code>$appName</code>
       <code>\OC_User::getUser()</code>
-      <code>\OC_User::getUser()</code>
     </InvalidScalarArgument>
     <TooManyArguments occurrences="1">
       <code>Util::addScript('dist/unified-search', null, true)</code>
diff --git a/core/Application.php b/core/Application.php
index a452ca9677fc4c9fb70eff2ff9af97245b9a730c..d9d6b92a2ad6fa1dec70a396a73750d6bff2f878 100644
--- a/core/Application.php
+++ b/core/Application.php
@@ -42,6 +42,7 @@ use OC\Authentication\Notifications\Notifier as AuthenticationNotifier;
 use OC\Core\Notification\RemoveLinkSharesNotifier;
 use OC\DB\MissingColumnInformation;
 use OC\DB\MissingIndexInformation;
+use OC\DB\MissingPrimaryKeyInformation;
 use OC\DB\SchemaWrapper;
 use OCP\AppFramework\App;
 use OCP\EventDispatcher\IEventDispatcher;
@@ -181,6 +182,63 @@ class Application extends App {
 			}
 		);
 
+		$oldEventDispatcher->addListener(IDBConnection::CHECK_MISSING_PRIMARY_KEYS_EVENT,
+			function (GenericEvent $event) use ($container) {
+				/** @var MissingPrimaryKeyInformation $subject */
+				$subject = $event->getSubject();
+
+				$schema = new SchemaWrapper($container->query(IDBConnection::class));
+
+				if ($schema->hasTable('federated_reshares')) {
+					$table = $schema->getTable('federated_reshares');
+
+					if (!$table->hasPrimaryKey()) {
+						$subject->addHintForMissingSubject($table->getName());
+					}
+				}
+
+				if ($schema->hasTable('systemtag_object_mapping')) {
+					$table = $schema->getTable('systemtag_object_mapping');
+
+					if (!$table->hasPrimaryKey()) {
+						$subject->addHintForMissingSubject($table->getName());
+					}
+				}
+
+				if ($schema->hasTable('comments_read_markers')) {
+					$table = $schema->getTable('comments_read_markers');
+
+					if (!$table->hasPrimaryKey()) {
+						$subject->addHintForMissingSubject($table->getName());
+					}
+				}
+
+				if ($schema->hasTable('collres_resources')) {
+					$table = $schema->getTable('collres_resources');
+
+					if (!$table->hasPrimaryKey()) {
+						$subject->addHintForMissingSubject($table->getName());
+					}
+				}
+
+				if ($schema->hasTable('collres_accesscache')) {
+					$table = $schema->getTable('collres_accesscache');
+
+					if (!$table->hasPrimaryKey()) {
+						$subject->addHintForMissingSubject($table->getName());
+					}
+				}
+
+				if ($schema->hasTable('filecache_extended')) {
+					$table = $schema->getTable('filecache_extended');
+
+					if (!$table->hasPrimaryKey()) {
+						$subject->addHintForMissingSubject($table->getName());
+					}
+				}
+			}
+		);
+
 		$oldEventDispatcher->addListener(IDBConnection::CHECK_MISSING_COLUMNS_EVENT,
 			function (GenericEvent $event) use ($container) {
 				/** @var MissingColumnInformation $subject */
diff --git a/core/Command/Db/AddMissingPrimaryKeys.php b/core/Command/Db/AddMissingPrimaryKeys.php
new file mode 100644
index 0000000000000000000000000000000000000000..a51249b1b8bdc7fe00e12c840c81f6f06372d5d7
--- /dev/null
+++ b/core/Command/Db/AddMissingPrimaryKeys.php
@@ -0,0 +1,181 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2017 Bjoern Schiessle <bjoern@schiessle.org>
+ *
+ * @author Bjoern Schiessle <bjoern@schiessle.org>
+ * @author Joas Schilling <coding@schilljs.com>
+ * @author Mario Danic <mario@lovelyhq.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <robin@icewind.nl>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ *
+ * @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 OC\Core\Command\Db;
+
+use OC\DB\SchemaWrapper;
+use OCP\IDBConnection;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\EventDispatcher\GenericEvent;
+
+/**
+ * Class AddMissingPrimaryKeys
+ *
+ * if you added primary keys to the database, this is the right place to add
+ * your update routine for existing instances
+ *
+ * @package OC\Core\Command\Db
+ */
+class AddMissingPrimaryKeys extends Command {
+
+	/** @var IDBConnection */
+	private $connection;
+
+	/** @var EventDispatcherInterface */
+	private $dispatcher;
+
+	public function __construct(IDBConnection $connection, EventDispatcherInterface $dispatcher) {
+		parent::__construct();
+
+		$this->connection = $connection;
+		$this->dispatcher = $dispatcher;
+	}
+
+	protected function configure() {
+		$this
+			->setName('db:add-missing-primary-keys')
+			->setDescription('Add missing primary keys to the database tables');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$this->addCorePrimaryKeys($output);
+
+		// Dispatch event so apps can also update indexes if needed
+		$event = new GenericEvent($output);
+		$this->dispatcher->dispatch(IDBConnection::ADD_MISSING_PRIMARY_KEYS_EVENT, $event);
+		return 0;
+	}
+
+	/**
+	 * add missing indices to the share table
+	 *
+	 * @param OutputInterface $output
+	 * @throws \Doctrine\DBAL\Schema\SchemaException
+	 */
+	private function addCorePrimaryKeys(OutputInterface $output) {
+		$output->writeln('<info>Check primary keys.</info>');
+
+		$schema = new SchemaWrapper($this->connection);
+		$updated = false;
+
+		if ($schema->hasTable('federated_reshares')) {
+			$table = $schema->getTable('federated_reshares');
+			if (!$table->hasPrimaryKey()) {
+				$output->writeln('<info>Adding primary key to the federated_reshares table, this can take some time...</info>');
+				$table->setPrimaryKey(['share_id'], 'federated_res_pk');
+				if ($table->hasIndex('share_id_index')) {
+					$table->dropIndex('share_id_index');
+				}
+				$this->connection->migrateToSchema($schema->getWrappedSchema());
+				$updated = true;
+				$output->writeln('<info>federated_reshares table updated successfully.</info>');
+			}
+		}
+
+		if ($schema->hasTable('systemtag_object_mapping')) {
+			$table = $schema->getTable('systemtag_object_mapping');
+			if (!$table->hasPrimaryKey()) {
+				$output->writeln('<info>Adding primary key to the systemtag_object_mapping table, this can take some time...</info>');
+				$table->setPrimaryKey(['objecttype', 'objectid', 'systemtagid'], 'som_pk');
+				if ($table->hasIndex('mapping')) {
+					$table->dropIndex('mapping');
+				}
+				$this->connection->migrateToSchema($schema->getWrappedSchema());
+				$updated = true;
+				$output->writeln('<info>systemtag_object_mapping table updated successfully.</info>');
+			}
+		}
+
+		if ($schema->hasTable('comments_read_markers')) {
+			$table = $schema->getTable('comments_read_markers');
+			if (!$table->hasPrimaryKey()) {
+				$output->writeln('<info>Adding primary key to the comments_read_markers table, this can take some time...</info>');
+				$table->setPrimaryKey(['user_id', 'object_type', 'object_id'], 'crm_pk');
+				if ($table->hasIndex('comments_marker_index')) {
+					$table->dropIndex('comments_marker_index');
+				}
+				$this->connection->migrateToSchema($schema->getWrappedSchema());
+				$updated = true;
+				$output->writeln('<info>comments_read_markers table updated successfully.</info>');
+			}
+		}
+
+		if ($schema->hasTable('collres_resources')) {
+			$table = $schema->getTable('collres_resources');
+			if (!$table->hasPrimaryKey()) {
+				$output->writeln('<info>Adding primary key to the collres_resources table, this can take some time...</info>');
+				$table->setPrimaryKey(['collection_id', 'resource_type', 'resource_id'], 'crr_pk');
+				if ($table->hasIndex('collres_unique_res')) {
+					$table->dropIndex('collres_unique_res');
+				}
+				$this->connection->migrateToSchema($schema->getWrappedSchema());
+				$updated = true;
+				$output->writeln('<info>collres_resources table updated successfully.</info>');
+			}
+		}
+
+		if ($schema->hasTable('collres_accesscache')) {
+			$table = $schema->getTable('collres_accesscache');
+			if (!$table->hasPrimaryKey()) {
+				$output->writeln('<info>Adding primary key to the collres_accesscache table, this can take some time...</info>');
+				$table->setPrimaryKey(['user_id', 'collection_id', 'resource_type', 'resource_id'], 'cra_pk');
+				if ($table->hasIndex('collres_unique_user')) {
+					$table->dropIndex('collres_unique_user');
+				}
+				$this->connection->migrateToSchema($schema->getWrappedSchema());
+				$updated = true;
+				$output->writeln('<info>collres_accesscache table updated successfully.</info>');
+			}
+		}
+
+		if ($schema->hasTable('filecache_extended')) {
+			$table = $schema->getTable('filecache_extended');
+			if (!$table->hasPrimaryKey()) {
+				$output->writeln('<info>Adding primary key to the filecache_extended table, this can take some time...</info>');
+				$table->setPrimaryKey(['fileid'], 'fce_pk');
+				if ($table->hasIndex('fce_fileid_idx')) {
+					$table->dropIndex('fce_fileid_idx');
+				}
+				$this->connection->migrateToSchema($schema->getWrappedSchema());
+				$updated = true;
+				$output->writeln('<info>filecache_extended table updated successfully.</info>');
+			}
+		}
+
+		if (!$updated) {
+			$output->writeln('<info>Done.</info>');
+		}
+	}
+}
diff --git a/core/Migrations/Version13000Date20170718121200.php b/core/Migrations/Version13000Date20170718121200.php
index d86477b5ab95ce7626333e2c2d1705111ebb457f..2a47bb52cfc90fd87dbc605818b90a09d11c5c0f 100644
--- a/core/Migrations/Version13000Date20170718121200.php
+++ b/core/Migrations/Version13000Date20170718121200.php
@@ -673,7 +673,8 @@ class Version13000Date20170718121200 extends SimpleMigrationStep {
 				'default' => 0,
 				'unsigned' => true,
 			]);
-			$table->addUniqueIndex(['objecttype', 'objectid', 'systemtagid'], 'mapping');
+			$table->setPrimaryKey(['objecttype', 'objectid', 'systemtagid'], 'som_pk');
+//			$table->addUniqueIndex(['objecttype', 'objectid', 'systemtagid'], 'mapping');
 		}
 
 		if (!$schema->hasTable('systemtag_group')) {
@@ -808,25 +809,26 @@ class Version13000Date20170718121200 extends SimpleMigrationStep {
 				'default' => '',
 			]);
 			$table->addIndex(['object_type', 'object_id'], 'comments_marker_object_index');
-			$table->addUniqueIndex(['user_id', 'object_type', 'object_id'], 'comments_marker_index');
+			$table->setPrimaryKey(['user_id', 'object_type', 'object_id'], 'crm_pk');
+//			$table->addUniqueIndex(['user_id', 'object_type', 'object_id'], 'comments_marker_index');
 		}
 
-		if (!$schema->hasTable('credentials')) {
-			$table = $schema->createTable('credentials');
-			$table->addColumn('user', 'string', [
-				'notnull' => true,
-				'length' => 64,
-			]);
-			$table->addColumn('identifier', 'string', [
-				'notnull' => true,
-				'length' => 64,
-			]);
-			$table->addColumn('credentials', 'text', [
-				'notnull' => false,
-			]);
-			$table->setPrimaryKey(['user', 'identifier']);
-			$table->addIndex(['user'], 'credentials_user');
-		}
+//		if (!$schema->hasTable('credentials')) {
+//			$table = $schema->createTable('credentials');
+//			$table->addColumn('user', 'string', [
+//				'notnull' => false,
+//				'length' => 64,
+//			]);
+//			$table->addColumn('identifier', 'string', [
+//				'notnull' => true,
+//				'length' => 64,
+//			]);
+//			$table->addColumn('credentials', 'text', [
+//				'notnull' => false,
+//			]);
+//			$table->setPrimaryKey(['user', 'identifier']);
+//			$table->addIndex(['user'], 'credentials_user');
+//		}
 
 		if (!$schema->hasTable('admin_sections')) {
 			$table = $schema->createTable('admin_sections');
diff --git a/core/Migrations/Version14000Date20180710092004.php b/core/Migrations/Version14000Date20180710092004.php
index 141b0c1afb5af9cef8c354dc401722287ebfbd51..767d8ee5f7dd31d59376fa7ed4db88d7b77e8e21 100644
--- a/core/Migrations/Version14000Date20180710092004.php
+++ b/core/Migrations/Version14000Date20180710092004.php
@@ -43,6 +43,7 @@ class Version14000Date20180710092004 extends SimpleMigrationStep {
 		if (!$table->hasColumn('password_by_talk')) {
 			$table->addColumn('password_by_talk', Types::BOOLEAN, [
 				'default' => 0,
+				'notnull' => false,
 			]);
 		}
 
diff --git a/core/Migrations/Version15000Date20180926101451.php b/core/Migrations/Version15000Date20180926101451.php
index a5f37cc91253e085896dd44ef72c9c27fe9b1428..e03a11318c0ed753b65cc39182ed922403fc9f08 100644
--- a/core/Migrations/Version15000Date20180926101451.php
+++ b/core/Migrations/Version15000Date20180926101451.php
@@ -45,8 +45,8 @@ class Version15000Date20180926101451 extends SimpleMigrationStep {
 
 		$table = $schema->getTable('authtoken');
 		$table->addColumn('password_invalid','boolean', [
-			'notnull' => true,
-			'default' => false,
+			'default' => 0,
+			'notnull' => false,
 		]);
 
 		return $schema;
diff --git a/core/Migrations/Version15000Date20181015062942.php b/core/Migrations/Version15000Date20181015062942.php
index eaeaf0dd268517c9aaee055533c1514da66a858b..23c2a904741bcd24453b0fb9a03ef883011236e3 100644
--- a/core/Migrations/Version15000Date20181015062942.php
+++ b/core/Migrations/Version15000Date20181015062942.php
@@ -45,7 +45,7 @@ class Version15000Date20181015062942 extends SimpleMigrationStep {
 
 		$table = $schema->getTable('share');
 		$table->addColumn('hide_download', 'smallint', [
-			'notnull' => true,
+			'notnull' => false,
 			'length' => 1,
 			'default' => 0,
 		]);
diff --git a/core/Migrations/Version16000Date20190207141427.php b/core/Migrations/Version16000Date20190207141427.php
index e6235efe20190eabaa47a9906e3a334e8e13acab..77a41dc3c4f9028be6ad9dc1cf4051b5c5a85da9 100644
--- a/core/Migrations/Version16000Date20190207141427.php
+++ b/core/Migrations/Version16000Date20190207141427.php
@@ -77,7 +77,8 @@ class Version16000Date20190207141427 extends SimpleMigrationStep {
 				'length' => 64,
 			]);
 
-			$table->addUniqueIndex(['collection_id', 'resource_type', 'resource_id'], 'collres_unique_res');
+			$table->setPrimaryKey(['collection_id', 'resource_type', 'resource_id'], 'crr_pk');
+//			$table->addUniqueIndex(['collection_id', 'resource_type', 'resource_id'], 'collres_unique_res');
 		}
 
 		if (!$schema->hasTable('collres_accesscache')) {
@@ -102,11 +103,12 @@ class Version16000Date20190207141427 extends SimpleMigrationStep {
 				'default' => '',
 			]);
 			$table->addColumn('access', Types::SMALLINT, [
-				'notnull' => true,
+				'notnull' => false,
 				'default' => 0,
 			]);
 
-			$table->addUniqueIndex(['user_id', 'collection_id', 'resource_type', 'resource_id'], 'collres_unique_user');
+			$table->setPrimaryKey(['user_id', 'collection_id', 'resource_type', 'resource_id'], 'cra_pk');
+//			$table->addUniqueIndex(['user_id', 'collection_id', 'resource_type', 'resource_id'], 'collres_unique_user');
 			$table->addIndex(['user_id', 'resource_type', 'resource_id'], 'collres_user_res');
 			$table->addIndex(['user_id', 'collection_id'], 'collres_user_coll');
 		}
diff --git a/core/Migrations/Version16000Date20190428150708.php b/core/Migrations/Version16000Date20190428150708.php
index 546d4c19e14965a717da9e712b48f73e00dcf171..dc33b08035ab7de120140bfa7f48474beaff37c8 100644
--- a/core/Migrations/Version16000Date20190428150708.php
+++ b/core/Migrations/Version16000Date20190428150708.php
@@ -49,7 +49,7 @@ class Version16000Date20190428150708 extends SimpleMigrationStep {
 		if ($schema->hasTable('collres_accesscache')) {
 			$table = $schema->getTable('collres_accesscache');
 			$table->addColumn('access', Types::BOOLEAN, [
-				'notnull' => true,
+				'notnull' => false,
 				'default' => false
 			]);
 		}
diff --git a/core/Migrations/Version17000Date20190514105811.php b/core/Migrations/Version17000Date20190514105811.php
index 910d82160709b23031d1a81ab69519501d82ec21..bd6ab1bc8a5bd7154da60ff9a3ca6aa2301d4048 100644
--- a/core/Migrations/Version17000Date20190514105811.php
+++ b/core/Migrations/Version17000Date20190514105811.php
@@ -67,7 +67,8 @@ class Version17000Date20190514105811 extends SimpleMigrationStep {
 				'length' => 20,
 				'default' => 0,
 			]);
-			$table->addUniqueIndex(['fileid'], 'fce_fileid_idx');
+			$table->setPrimaryKey(['fileid'], 'fce_pk');
+//			$table->addUniqueIndex(['fileid'], 'fce_fileid_idx');
 			$table->addIndex(['creation_time'], 'fce_ctime_idx');
 			$table->addIndex(['upload_time'], 'fce_utime_idx');
 		}
diff --git a/core/Migrations/Version18000Date20191204114856.php b/core/Migrations/Version18000Date20191204114856.php
index e9bf1221dbf7f5e17d5c7d8a77d0f02b1c29d139..0e5f3cbe2723f5815b7e44aecaabee236d9c6411 100644
--- a/core/Migrations/Version18000Date20191204114856.php
+++ b/core/Migrations/Version18000Date20191204114856.php
@@ -58,7 +58,6 @@ class Version18000Date20191204114856 extends SimpleMigrationStep {
 			'length' => 4000,
 		]);
 
-
 		return $schema;
 	}
 }
diff --git a/core/Migrations/Version20000Date20201109081915.php b/core/Migrations/Version20000Date20201109081915.php
new file mode 100644
index 0000000000000000000000000000000000000000..73c5ef641abc10ab15ee471a2ed8b10926735ae4
--- /dev/null
+++ b/core/Migrations/Version20000Date20201109081915.php
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020 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 OC\Core\Migrations;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+class Version20000Date20201109081915 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): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$result = $this->ensureColumnIsNullable($schema, 'share', 'password_by_talk');
+		$result = $this->ensureColumnIsNullable($schema, 'share', 'hide_download') || $result;
+//		$result = $this->ensureColumnIsNullable($schema, 'credentials', 'user') || $result;
+		$result = $this->ensureColumnIsNullable($schema, 'authtoken', 'password_invalid') || $result;
+		$result = $this->ensureColumnIsNullable($schema, 'collres_accesscache', 'access') || $result;
+
+		return $result ? $schema : null;
+	}
+
+	protected function ensureColumnIsNullable(ISchemaWrapper $schema, string $tableName, string $columnName): bool {
+		$table = $schema->getTable($tableName);
+		$column = $table->getColumn($columnName);
+
+		if ($column->getNotnull()) {
+			$column->setNotnull(false);
+			return true;
+		}
+
+		return false;
+	}
+}
diff --git a/core/Migrations/Version20000Date20201109081918.php b/core/Migrations/Version20000Date20201109081918.php
new file mode 100644
index 0000000000000000000000000000000000000000..cea71148bc15de1dfa9f24d301d990ec1452b4ab
--- /dev/null
+++ b/core/Migrations/Version20000Date20201109081918.php
@@ -0,0 +1,108 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020 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 OC\Core\Migrations;
+
+use Closure;
+use Doctrine\DBAL\Types\Type;
+use OCP\DB\ISchemaWrapper;
+use OCP\IDBConnection;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+class Version20000Date20201109081918 extends SimpleMigrationStep {
+
+	/** @var IDBConnection */
+	protected $connection;
+
+	public function __construct(IDBConnection $connection) {
+		$this->connection = $connection;
+	}
+
+	/**
+	 * @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): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$table = $schema->createTable('storages_credentials');
+		$table->addColumn('id', Type::BIGINT, [
+			'autoincrement' => true,
+			'notnull' => true,
+			'length' => 64,
+		]);
+		$table->addColumn('user', Type::STRING, [
+			'notnull' => false,
+			'length' => 64,
+		]);
+		$table->addColumn('identifier', Type::STRING, [
+			'notnull' => true,
+			'length' => 64,
+		]);
+		$table->addColumn('credentials', Type::TEXT, [
+			'notnull' => false,
+		]);
+		$table->setPrimaryKey(['id']);
+		$table->addUniqueIndex(['user', 'identifier'], 'stocred_ui');
+		$table->addIndex(['user'], 'stocred_user');
+
+		return $schema;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @since 13.0.0
+	 */
+	public function postSchemaChange(IOutput $output, \Closure $schemaClosure, array $options): void {
+		if (!$this->connection->tableExists('credentials')) {
+			return;
+		}
+
+		$query = $this->connection->getQueryBuilder();
+		$query->select('*')
+			->from('credentials');
+
+		$insert = $this->connection->getQueryBuilder();
+		$insert->insert('storages_credentials')
+			->setValue('user', $insert->createNamedParameter('user'))
+			->setValue('identifier', $insert->createNamedParameter('identifier'))
+			->setValue('credentials', $insert->createNamedParameter('credentials'));
+
+		$result = $query->execute();
+		while ($row = $result->fetch()) {
+			$insert->setParameter('user', (string) $row['user'])
+				->setParameter('identifier', (string) $row['identifier'])
+				->setParameter('credentials', (string) $row['credentials']);
+			$insert->execute();
+		}
+		$result->closeCursor();
+	}
+}
diff --git a/core/Migrations/Version20000Date20201109081919.php b/core/Migrations/Version20000Date20201109081919.php
new file mode 100644
index 0000000000000000000000000000000000000000..cfc1ec4f03b0079567b4a2b9b08d30283357c3a2
--- /dev/null
+++ b/core/Migrations/Version20000Date20201109081919.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020 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 OC\Core\Migrations;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+class Version20000Date20201109081919 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): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		if ($schema->hasTable('credentials')) {
+			$schema->dropTable('credentials');
+			return $schema;
+		}
+
+		return null;
+	}
+}
diff --git a/core/js/setupchecks.js b/core/js/setupchecks.js
index e8bcc72cb3362f04aab90ba92794679981af3b8d..214f148fa943c60a0b984680db1e7c56df4a8d94 100644
--- a/core/js/setupchecks.js
+++ b/core/js/setupchecks.js
@@ -357,6 +357,21 @@
 							type: OC.SetupChecks.MESSAGE_TYPE_INFO
 						})
 					}
+					if (data.missingPrimaryKeys.length > 0) {
+						var listOfMissingPrimaryKeys = "";
+						data.missingPrimaryKeys.forEach(function(element){
+							listOfMissingPrimaryKeys += "<li>";
+							listOfMissingPrimaryKeys += t('core', 'Missing primary key on table "{tableName}".', element);
+							listOfMissingPrimaryKeys += "</li>";
+						});
+						messages.push({
+							msg: t(
+								'core',
+								'The database is missing some primary keys. Due to the fact that adding primary keys on big tables could take some time they were not added automatically. By running "occ db:add-missing-primary-keys" those missing primary keys could be added manually while the instance keeps running.'
+							) + "<ul>" + listOfMissingPrimaryKeys + "</ul>",
+							type: OC.SetupChecks.MESSAGE_TYPE_INFO
+						})
+					}
 					if (data.missingColumns.length > 0) {
 						var listOfMissingColumns = "";
 						data.missingColumns.forEach(function(element){
diff --git a/core/js/tests/specs/setupchecksSpec.js b/core/js/tests/specs/setupchecksSpec.js
index f4c81c6bf78ed6a9945e95e4892d4d48b50a1c80..3b54a3ff66a46f3f0d22933c32b2e9bbc8ee646f 100644
--- a/core/js/tests/specs/setupchecksSpec.js
+++ b/core/js/tests/specs/setupchecksSpec.js
@@ -240,6 +240,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -294,6 +295,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -349,6 +351,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -402,6 +405,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -453,6 +457,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -504,6 +509,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -557,6 +563,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -608,6 +615,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: false,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -659,6 +667,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -731,6 +740,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -783,6 +793,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -835,6 +846,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -887,6 +899,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: false,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -938,6 +951,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -989,6 +1003,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
@@ -1041,6 +1056,7 @@ describe('OC.SetupChecks tests', function() {
 					isSettimelimitAvailable: true,
 					hasFreeTypeSupport: true,
 					missingIndexes: [],
+					missingPrimaryKeys: [],
 					missingColumns: [],
 					cronErrors: [],
 					cronInfo: {
diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 5c94e2f39f30322c768c43a00476a2cc79bae9b4..b88f877b92cac4973b00f5b3eb75f3e7847e0f41 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -799,6 +799,7 @@ return array(
     'OC\\Core\\Command\\Config\\System\\SetConfig' => $baseDir . '/core/Command/Config/System/SetConfig.php',
     'OC\\Core\\Command\\Db\\AddMissingColumns' => $baseDir . '/core/Command/Db/AddMissingColumns.php',
     'OC\\Core\\Command\\Db\\AddMissingIndices' => $baseDir . '/core/Command/Db/AddMissingIndices.php',
+    'OC\\Core\\Command\\Db\\AddMissingPrimaryKeys' => $baseDir . '/core/Command/Db/AddMissingPrimaryKeys.php',
     'OC\\Core\\Command\\Db\\ConvertFilecacheBigInt' => $baseDir . '/core/Command/Db/ConvertFilecacheBigInt.php',
     'OC\\Core\\Command\\Db\\ConvertMysqlToMB4' => $baseDir . '/core/Command/Db/ConvertMysqlToMB4.php',
     'OC\\Core\\Command\\Db\\ConvertType' => $baseDir . '/core/Command/Db/ConvertType.php',
@@ -922,6 +923,9 @@ return array(
     'OC\\Core\\Migrations\\Version18000Date20191014105105' => $baseDir . '/core/Migrations/Version18000Date20191014105105.php',
     'OC\\Core\\Migrations\\Version18000Date20191204114856' => $baseDir . '/core/Migrations/Version18000Date20191204114856.php',
     'OC\\Core\\Migrations\\Version19000Date20200211083441' => $baseDir . '/core/Migrations/Version19000Date20200211083441.php',
+    'OC\\Core\\Migrations\\Version20000Date20201109081915' => $baseDir . '/core/Migrations/Version20000Date20201109081915.php',
+    'OC\\Core\\Migrations\\Version20000Date20201109081918' => $baseDir . '/core/Migrations/Version20000Date20201109081918.php',
+    'OC\\Core\\Migrations\\Version20000Date20201109081919' => $baseDir . '/core/Migrations/Version20000Date20201109081919.php',
     'OC\\Core\\Notification\\RemoveLinkSharesNotifier' => $baseDir . '/core/Notification/RemoveLinkSharesNotifier.php',
     'OC\\Core\\Service\\LoginFlowV2Service' => $baseDir . '/core/Service/LoginFlowV2Service.php',
     'OC\\DB\\Adapter' => $baseDir . '/lib/private/DB/Adapter.php',
@@ -939,6 +943,7 @@ return array(
     'OC\\DB\\Migrator' => $baseDir . '/lib/private/DB/Migrator.php',
     'OC\\DB\\MissingColumnInformation' => $baseDir . '/lib/private/DB/MissingColumnInformation.php',
     'OC\\DB\\MissingIndexInformation' => $baseDir . '/lib/private/DB/MissingIndexInformation.php',
+    'OC\\DB\\MissingPrimaryKeyInformation' => $baseDir . '/lib/private/DB/MissingPrimaryKeyInformation.php',
     'OC\\DB\\MySQLMigrator' => $baseDir . '/lib/private/DB/MySQLMigrator.php',
     'OC\\DB\\MySqlTools' => $baseDir . '/lib/private/DB/MySqlTools.php',
     'OC\\DB\\OCSqlitePlatform' => $baseDir . '/lib/private/DB/OCSqlitePlatform.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 48c311bfbbcf193229115b4eee65d8eeebc9e344..2c0b5b19325e39b7282b0b6bc06b6b93b98005c5 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -828,6 +828,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Core\\Command\\Config\\System\\SetConfig' => __DIR__ . '/../../..' . '/core/Command/Config/System/SetConfig.php',
         'OC\\Core\\Command\\Db\\AddMissingColumns' => __DIR__ . '/../../..' . '/core/Command/Db/AddMissingColumns.php',
         'OC\\Core\\Command\\Db\\AddMissingIndices' => __DIR__ . '/../../..' . '/core/Command/Db/AddMissingIndices.php',
+        'OC\\Core\\Command\\Db\\AddMissingPrimaryKeys' => __DIR__ . '/../../..' . '/core/Command/Db/AddMissingPrimaryKeys.php',
         'OC\\Core\\Command\\Db\\ConvertFilecacheBigInt' => __DIR__ . '/../../..' . '/core/Command/Db/ConvertFilecacheBigInt.php',
         'OC\\Core\\Command\\Db\\ConvertMysqlToMB4' => __DIR__ . '/../../..' . '/core/Command/Db/ConvertMysqlToMB4.php',
         'OC\\Core\\Command\\Db\\ConvertType' => __DIR__ . '/../../..' . '/core/Command/Db/ConvertType.php',
@@ -951,6 +952,9 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Core\\Migrations\\Version18000Date20191014105105' => __DIR__ . '/../../..' . '/core/Migrations/Version18000Date20191014105105.php',
         'OC\\Core\\Migrations\\Version18000Date20191204114856' => __DIR__ . '/../../..' . '/core/Migrations/Version18000Date20191204114856.php',
         'OC\\Core\\Migrations\\Version19000Date20200211083441' => __DIR__ . '/../../..' . '/core/Migrations/Version19000Date20200211083441.php',
+        'OC\\Core\\Migrations\\Version20000Date20201109081915' => __DIR__ . '/../../..' . '/core/Migrations/Version20000Date20201109081915.php',
+        'OC\\Core\\Migrations\\Version20000Date20201109081918' => __DIR__ . '/../../..' . '/core/Migrations/Version20000Date20201109081918.php',
+        'OC\\Core\\Migrations\\Version20000Date20201109081919' => __DIR__ . '/../../..' . '/core/Migrations/Version20000Date20201109081919.php',
         'OC\\Core\\Notification\\RemoveLinkSharesNotifier' => __DIR__ . '/../../..' . '/core/Notification/RemoveLinkSharesNotifier.php',
         'OC\\Core\\Service\\LoginFlowV2Service' => __DIR__ . '/../../..' . '/core/Service/LoginFlowV2Service.php',
         'OC\\DB\\Adapter' => __DIR__ . '/../../..' . '/lib/private/DB/Adapter.php',
@@ -968,6 +972,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\DB\\Migrator' => __DIR__ . '/../../..' . '/lib/private/DB/Migrator.php',
         'OC\\DB\\MissingColumnInformation' => __DIR__ . '/../../..' . '/lib/private/DB/MissingColumnInformation.php',
         'OC\\DB\\MissingIndexInformation' => __DIR__ . '/../../..' . '/lib/private/DB/MissingIndexInformation.php',
+        'OC\\DB\\MissingPrimaryKeyInformation' => __DIR__ . '/../../..' . '/lib/private/DB/MissingPrimaryKeyInformation.php',
         'OC\\DB\\MySQLMigrator' => __DIR__ . '/../../..' . '/lib/private/DB/MySQLMigrator.php',
         'OC\\DB\\MySqlTools' => __DIR__ . '/../../..' . '/lib/private/DB/MySqlTools.php',
         'OC\\DB\\OCSqlitePlatform' => __DIR__ . '/../../..' . '/lib/private/DB/OCSqlitePlatform.php',
diff --git a/lib/private/DB/Connection.php b/lib/private/DB/Connection.php
index 6835226357f71673dedf4bacece29d6d955fc681..ebb3900f3e53ea89054e1d5e2de57912b9beb412 100644
--- a/lib/private/DB/Connection.php
+++ b/lib/private/DB/Connection.php
@@ -39,6 +39,7 @@ use Doctrine\DBAL\Configuration;
 use Doctrine\DBAL\DBALException;
 use Doctrine\DBAL\Driver;
 use Doctrine\DBAL\Exception\ConstraintViolationException;
+use Doctrine\DBAL\Exception\NotNullConstraintViolationException;
 use Doctrine\DBAL\Platforms\MySqlPlatform;
 use Doctrine\DBAL\Schema\Schema;
 use OC\DB\QueryBuilder\QueryBuilder;
@@ -322,6 +323,8 @@ class Connection extends ReconnectWrapper implements IDBConnection {
 					}, array_merge($keys, $values))
 				);
 			return $insertQb->execute();
+		} catch (NotNullConstraintViolationException $e) {
+			throw $e;
 		} catch (ConstraintViolationException $e) {
 			// value already exists, try update
 			$updateQb = $this->getQueryBuilder();
@@ -332,11 +335,17 @@ class Connection extends ReconnectWrapper implements IDBConnection {
 			$where = $updateQb->expr()->andX();
 			$whereValues = array_merge($keys, $updatePreconditionValues);
 			foreach ($whereValues as $name => $value) {
-				$where->add($updateQb->expr()->eq(
-					$name,
-					$updateQb->createNamedParameter($value, $this->getType($value)),
-					$this->getType($value)
-				));
+				if ($value === '') {
+					$where->add($updateQb->expr()->emptyString(
+						$name
+					));
+				} else {
+					$where->add($updateQb->expr()->eq(
+						$name,
+						$updateQb->createNamedParameter($value, $this->getType($value)),
+						$this->getType($value)
+					));
+				}
 			}
 			$updateQb->where($where);
 			$affected = $updateQb->execute();
diff --git a/lib/private/DB/MissingPrimaryKeyInformation.php b/lib/private/DB/MissingPrimaryKeyInformation.php
new file mode 100644
index 0000000000000000000000000000000000000000..c6b81ddba4ed8b89d19ea25e0a983d0ec01ee511
--- /dev/null
+++ b/lib/private/DB/MissingPrimaryKeyInformation.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2018 Morris Jobke <hey@morrisjobke.de>
+ *
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @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 OC\DB;
+
+class MissingPrimaryKeyInformation {
+	private $listOfMissingPrimaryKeys = [];
+
+	public function addHintForMissingSubject(string $tableName) {
+		$this->listOfMissingPrimaryKeys[] = [
+			'tableName' => $tableName,
+		];
+	}
+
+	public function getListOfMissingPrimaryKeys(): array {
+		return $this->listOfMissingPrimaryKeys;
+	}
+}
diff --git a/lib/private/Files/Cache/Cache.php b/lib/private/Files/Cache/Cache.php
index e74cc86d9c9cdaf1158b7c91f526769ef43f7041..1d3b4da3bce0cd08fa0c62ccc3cb55af46dc09e7 100644
--- a/lib/private/Files/Cache/Cache.php
+++ b/lib/private/Files/Cache/Cache.php
@@ -998,7 +998,11 @@ class Cache implements ICache {
 		$path = $result->fetchColumn();
 		$result->closeCursor();
 
-		return $path === false ? null : $path;
+		if ($path === false) {
+			return null;
+		}
+
+		return (string) $path;
 	}
 
 	/**
diff --git a/lib/private/Security/CredentialsManager.php b/lib/private/Security/CredentialsManager.php
index a40a7e1d88e9f457f9f415364e2972922961347b..2a480ef71053b7e2f0376aa9bb42e208bcce0d51 100644
--- a/lib/private/Security/CredentialsManager.php
+++ b/lib/private/Security/CredentialsManager.php
@@ -35,7 +35,7 @@ use OCP\Security\ICrypto;
  * @package OC\Security
  */
 class CredentialsManager implements ICredentialsManager {
-	public const DB_TABLE = 'credentials';
+	public const DB_TABLE = 'storages_credentials';
 
 	/** @var ICrypto */
 	protected $crypto;
@@ -81,9 +81,13 @@ class CredentialsManager implements ICredentialsManager {
 		$qb = $this->dbConnection->getQueryBuilder();
 		$qb->select('credentials')
 			->from(self::DB_TABLE)
-			->where($qb->expr()->eq('user', $qb->createNamedParameter((string)$userId)))
-			->andWhere($qb->expr()->eq('identifier', $qb->createNamedParameter($identifier)))
-		;
+			->where($qb->expr()->eq('identifier', $qb->createNamedParameter($identifier)));
+
+		if ($userId === '') {
+			$qb->andWhere($qb->expr()->emptyString('user'));
+		} else {
+			$qb->andWhere($qb->expr()->eq('user', $qb->createNamedParameter((string)$userId)));
+		}
 
 		$qResult = $qb->execute();
 		$result = $qResult->fetch();
@@ -107,9 +111,14 @@ class CredentialsManager implements ICredentialsManager {
 	public function delete($userId, $identifier) {
 		$qb = $this->dbConnection->getQueryBuilder();
 		$qb->delete(self::DB_TABLE)
-			->where($qb->expr()->eq('user', $qb->createNamedParameter((string)$userId)))
-			->andWhere($qb->expr()->eq('identifier', $qb->createNamedParameter($identifier)))
-		;
+			->where($qb->expr()->eq('identifier', $qb->createNamedParameter($identifier)));
+
+		if ($userId === '') {
+			$qb->andWhere($qb->expr()->emptyString('user'));
+		} else {
+			$qb->andWhere($qb->expr()->eq('user', $qb->createNamedParameter((string)$userId)));
+		}
+
 		return $qb->execute();
 	}
 
diff --git a/lib/private/Share20/DefaultShareProvider.php b/lib/private/Share20/DefaultShareProvider.php
index e43529086fd158d2061f4a17371e1461a3fa794d..b4ac3b3b84dce762924dbea647dd40bf12d0ce3e 100644
--- a/lib/private/Share20/DefaultShareProvider.php
+++ b/lib/private/Share20/DefaultShareProvider.php
@@ -874,6 +874,11 @@ class DefaultShareProvider implements IShareProvider {
 			$cursor = $qb->execute();
 
 			while ($data = $cursor->fetch()) {
+				if ($data['fileid'] && $data['path'] === null) {
+					$data['path'] = (string) $data['path'];
+					$data['name'] = (string) $data['name'];
+					$data['checksum'] = (string) $data['checksum'];
+				}
 				if ($this->isAccessibleResult($data)) {
 					$shares[] = $this->createShare($data);
 				}
@@ -1004,7 +1009,7 @@ class DefaultShareProvider implements IShareProvider {
 			->setShareType((int)$data['share_type'])
 			->setPermissions((int)$data['permissions'])
 			->setTarget($data['file_target'])
-			->setNote($data['note'])
+			->setNote((string)$data['note'])
 			->setMailSend((bool)$data['mail_send'])
 			->setStatus((int)$data['accepted'])
 			->setLabel($data['label']);
diff --git a/lib/public/IDBConnection.php b/lib/public/IDBConnection.php
index 8e20b5503ba15cf1f6654ea1b4a0fe521cf319a5..11fa301ab863568fcba00dbda64203470e0c5ac2 100644
--- a/lib/public/IDBConnection.php
+++ b/lib/public/IDBConnection.php
@@ -50,6 +50,8 @@ use OCP\DB\QueryBuilder\IQueryBuilder;
 interface IDBConnection {
 	public const ADD_MISSING_INDEXES_EVENT = self::class . '::ADD_MISSING_INDEXES';
 	public const CHECK_MISSING_INDEXES_EVENT = self::class . '::CHECK_MISSING_INDEXES';
+	public const ADD_MISSING_PRIMARY_KEYS_EVENT = self::class . '::ADD_MISSING_PRIMARY_KEYS';
+	public const CHECK_MISSING_PRIMARY_KEYS_EVENT = self::class . '::CHECK_MISSING_PRIMARY_KEYS';
 	public const ADD_MISSING_COLUMNS_EVENT = self::class . '::ADD_MISSING_COLUMNS';
 	public const CHECK_MISSING_COLUMNS_EVENT = self::class . '::CHECK_MISSING_COLUMNS';
 
diff --git a/tests/lib/AppConfigTest.php b/tests/lib/AppConfigTest.php
index ff23454eb8bc6db9b8ed5d3d1bd2d8ccc609fe32..40a99709bd5a45d6ea0258f7a64e3f238e034335 100644
--- a/tests/lib/AppConfigTest.php
+++ b/tests/lib/AppConfigTest.php
@@ -9,6 +9,7 @@
 
 namespace Test;
 
+use OC\AppConfig;
 use OCP\IConfig;
 
 /**
@@ -42,7 +43,7 @@ class AppConfigTest extends TestCase {
 		$sql->delete('appconfig');
 		$sql->execute();
 
-		$this->overwriteService('AppConfig', new \OC\AppConfig($this->connection));
+		$this->overwriteService(AppConfig::class, new \OC\AppConfig($this->connection));
 
 		$sql = $this->connection->getQueryBuilder();
 		$sql->insert('appconfig')
@@ -132,7 +133,7 @@ class AppConfigTest extends TestCase {
 			$sql->execute();
 		}
 
-		$this->restoreService('AppConfig');
+		$this->restoreService(AppConfig::class);
 		parent::tearDown();
 	}
 
diff --git a/tests/lib/DB/ConnectionTest.php b/tests/lib/DB/ConnectionTest.php
index be84cb81cb3087876fcbf64abfb01c99f8480142..cab6133c3c08697c57293e222d2220687be608e2 100644
--- a/tests/lib/DB/ConnectionTest.php
+++ b/tests/lib/DB/ConnectionTest.php
@@ -97,14 +97,17 @@ class ConnectionTest extends \Test\TestCase {
 		$this->assertTableNotExist('table');
 	}
 
-	private function getTextValueByIntergerField($integerField) {
+	private function getTextValueByIntegerField($integerField) {
 		$builder = $this->connection->getQueryBuilder();
-		$query = $builder->select('textfield')
+		$query = $builder->select('*')
 			->from('table')
 			->where($builder->expr()->eq('integerfield', $builder->createNamedParameter($integerField, IQueryBuilder::PARAM_INT)));
 
 		$result = $query->execute();
-		return $result->fetchColumn();
+		$row = $result->fetch();
+		$result->closeCursor();
+
+		return $row['textfield'] ?? null;
 	}
 
 	public function testSetValues() {
@@ -116,7 +119,7 @@ class ConnectionTest extends \Test\TestCase {
 			'clobfield' => 'not_null'
 		]);
 
-		$this->assertEquals('foo', $this->getTextValueByIntergerField(1));
+		$this->assertEquals('foo', $this->getTextValueByIntegerField(1));
 	}
 
 	public function testSetValuesOverWrite() {
@@ -133,7 +136,7 @@ class ConnectionTest extends \Test\TestCase {
 			'textfield' => 'bar'
 		]);
 
-		$this->assertEquals('bar', $this->getTextValueByIntergerField(1));
+		$this->assertEquals('bar', $this->getTextValueByIntegerField(1));
 	}
 
 	public function testSetValuesOverWritePrecondition() {
@@ -154,7 +157,7 @@ class ConnectionTest extends \Test\TestCase {
 			'booleanfield' => true
 		]);
 
-		$this->assertEquals('bar', $this->getTextValueByIntergerField(1));
+		$this->assertEquals('bar', $this->getTextValueByIntegerField(1));
 	}
 
 
@@ -200,6 +203,10 @@ class ConnectionTest extends \Test\TestCase {
 	}
 
 	public function testInsertIfNotExist() {
+		if (\OC::$server->getConfig()->getSystemValue('dbtype', 'sqlite') === 'oci') {
+			self::markTestSkipped('Insert if not exist does not work with clob on oracle');
+		}
+
 		$this->makeTestTable();
 		$categoryEntries = [
 			['user' => 'test', 'category' => 'Family',    'expectedResult' => 1],
@@ -213,13 +220,15 @@ class ConnectionTest extends \Test\TestCase {
 			['user' => 'test2', 'category' => 'Coworkers', 'expectedResult' => 1],
 		];
 
+		$row = 0;
 		foreach ($categoryEntries as $entry) {
 			$result = $this->connection->insertIfNotExist('*PREFIX*table',
 				[
 					'textfield' => $entry['user'],
 					'clobfield' => $entry['category'],
-				]);
-			$this->assertEquals($entry['expectedResult'], $result);
+					'integerfield' => $row++,
+				], ['textfield', 'clobfield']);
+			$this->assertEquals($entry['expectedResult'], $result, json_encode($entry));
 		}
 
 		$query = $this->connection->prepare('SELECT * FROM `*PREFIX*table`');
@@ -229,6 +238,10 @@ class ConnectionTest extends \Test\TestCase {
 	}
 
 	public function testInsertIfNotExistNull() {
+		if (\OC::$server->getConfig()->getSystemValue('dbtype', 'sqlite') === 'oci') {
+			self::markTestSkipped('Insert if not exist does not work with clob on oracle');
+		}
+
 		$this->makeTestTable();
 		$categoryEntries = [
 			['addressbookid' => 123, 'fullname' => null, 'expectedResult' => 1],
@@ -236,13 +249,15 @@ class ConnectionTest extends \Test\TestCase {
 			['addressbookid' => 123, 'fullname' => 'test', 'expectedResult' => 1],
 		];
 
+		$row = 0;
 		foreach ($categoryEntries as $entry) {
 			$result = $this->connection->insertIfNotExist('*PREFIX*table',
 				[
 					'integerfield_default' => $entry['addressbookid'],
 					'clobfield' => $entry['fullname'],
-				]);
-			$this->assertEquals($entry['expectedResult'], $result);
+					'integerfield' => $row++,
+				], ['integerfield_default', 'clobfield']);
+			$this->assertEquals($entry['expectedResult'], $result, json_encode($entry));
 		}
 
 		$query = $this->connection->prepare('SELECT * FROM `*PREFIX*table`');
@@ -252,6 +267,10 @@ class ConnectionTest extends \Test\TestCase {
 	}
 
 	public function testInsertIfNotExistDonTOverwrite() {
+		if (\OC::$server->getConfig()->getSystemValue('dbtype', 'sqlite') === 'oci') {
+			self::markTestSkipped('Insert if not exist does not work with clob on oracle');
+		}
+
 		$this->makeTestTable();
 		$fullName = 'fullname test';
 		$uri = 'uri_1';
@@ -288,6 +307,10 @@ class ConnectionTest extends \Test\TestCase {
 	}
 
 	public function testInsertIfNotExistsViolating() {
+		if (\OC::$server->getConfig()->getSystemValue('dbtype', 'sqlite') === 'oci') {
+			self::markTestSkipped('Insert if not exist does not work with clob on oracle');
+		}
+
 		$this->makeTestTable();
 		$result = $this->connection->insertIfNotExist('*PREFIX*table',
 			[
@@ -318,6 +341,10 @@ class ConnectionTest extends \Test\TestCase {
 	 * @param array $compareKeys
 	 */
 	public function testInsertIfNotExistsViolatingUnique($compareKeys) {
+		if (\OC::$server->getConfig()->getSystemValue('dbtype', 'sqlite') === 'oci') {
+			self::markTestSkipped('Insert if not exist does not work with clob on oracle');
+		}
+
 		$this->makeTestTable();
 		$result = $this->connection->insertIfNotExist('*PREFIX*table',
 			[
diff --git a/tests/lib/DB/MDB2SchemaReaderTest.php b/tests/lib/DB/MDB2SchemaReaderTest.php
index c57b0f22b6fc39f7d8d463fdf476a553047e4cb4..b3dd98fd6b75dbf1532c4ed3b18ba62ff26dd51f 100644
--- a/tests/lib/DB/MDB2SchemaReaderTest.php
+++ b/tests/lib/DB/MDB2SchemaReaderTest.php
@@ -14,6 +14,10 @@ use Doctrine\DBAL\Schema\Schema;
 use OC\DB\MDB2SchemaReader;
 use OCP\IConfig;
 use Test\TestCase;
+use Doctrine\DBAL\Types\IntegerType;
+use Doctrine\DBAL\Types\TextType;
+use Doctrine\DBAL\Types\StringType;
+use Doctrine\DBAL\Types\BooleanType;
 
 /**
  * Class MDB2SchemaReaderTest
@@ -51,13 +55,13 @@ class MDB2SchemaReaderTest extends TestCase {
 		$this->assertCount(1, $schema->getTables());
 
 		$table = $schema->getTable('test_table');
-		$this->assertCount(8, $table->getColumns());
+		$this->assertCount(9, $table->getColumns());
 
-		$this->assertEquals(4, $table->getColumn('integerfield')->getLength());
-		$this->assertTrue($table->getColumn('integerfield')->getAutoincrement());
-		$this->assertEquals(0, $table->getColumn('integerfield')->getDefault());
-		$this->assertTrue($table->getColumn('integerfield')->getNotnull());
-		$this->assertInstanceOf('Doctrine\DBAL\Types\IntegerType', $table->getColumn('integerfield')->getType());
+		$this->assertEquals(4, $table->getColumn('id')->getLength());
+		$this->assertTrue($table->getColumn('id')->getAutoincrement());
+		$this->assertEquals(0, $table->getColumn('id')->getDefault());
+		$this->assertTrue($table->getColumn('id')->getNotnull());
+		$this->assertInstanceOf(IntegerType::class, $table->getColumn('id')->getType());
 
 		$this->assertSame(10, $table->getColumn('integerfield_default')->getDefault());
 
@@ -65,18 +69,19 @@ class MDB2SchemaReaderTest extends TestCase {
 		$this->assertFalse($table->getColumn('textfield')->getAutoincrement());
 		$this->assertSame('foo', $table->getColumn('textfield')->getDefault());
 		$this->assertTrue($table->getColumn('textfield')->getNotnull());
-		$this->assertInstanceOf('Doctrine\DBAL\Types\StringType', $table->getColumn('textfield')->getType());
+		$this->assertInstanceOf(StringType::class, $table->getColumn('textfield')->getType());
 
 		$this->assertNull($table->getColumn('clobfield')->getLength());
 		$this->assertFalse($table->getColumn('clobfield')->getAutoincrement());
 		$this->assertNull($table->getColumn('clobfield')->getDefault());
 		$this->assertFalse($table->getColumn('clobfield')->getNotnull());
-		$this->assertInstanceOf('Doctrine\DBAL\Types\TextType', $table->getColumn('clobfield')->getType());
+		$this->assertInstanceOf(StringType::class, $table->getColumn('clobfield')->getType());
+//		$this->assertInstanceOf(TextType::class, $table->getColumn('clobfield')->getType());
 
 		$this->assertNull($table->getColumn('booleanfield')->getLength());
 		$this->assertFalse($table->getColumn('booleanfield')->getAutoincrement());
 		$this->assertNull($table->getColumn('booleanfield')->getDefault());
-		$this->assertInstanceOf('Doctrine\DBAL\Types\BooleanType', $table->getColumn('booleanfield')->getType());
+		$this->assertInstanceOf(BooleanType::class, $table->getColumn('booleanfield')->getType());
 
 		$this->assertTrue($table->getColumn('booleanfield_true')->getDefault());
 		$this->assertFalse($table->getColumn('booleanfield_false')->getDefault());
@@ -84,10 +89,13 @@ class MDB2SchemaReaderTest extends TestCase {
 		$this->assertEquals(12, $table->getColumn('decimalfield_precision_scale')->getPrecision());
 		$this->assertEquals(2, $table->getColumn('decimalfield_precision_scale')->getScale());
 
-		$this->assertCount(2, $table->getIndexes());
-		$this->assertEquals(['integerfield'], $table->getIndex('primary')->getUnquotedColumns());
+		$this->assertCount(3, $table->getIndexes());
+		$this->assertEquals(['id'], $table->getIndex('primary')->getUnquotedColumns());
 		$this->assertTrue($table->getIndex('primary')->isPrimary());
 		$this->assertTrue($table->getIndex('primary')->isUnique());
+		$this->assertEquals(['integerfield'], $table->getIndex('index_integerfield')->getUnquotedColumns());
+		$this->assertFalse($table->getIndex('index_integerfield')->isPrimary());
+		$this->assertTrue($table->getIndex('index_integerfield')->isUnique());
 		$this->assertEquals(['booleanfield'], $table->getIndex('index_boolean')->getUnquotedColumns());
 		$this->assertFalse($table->getIndex('index_boolean')->isPrimary());
 		$this->assertFalse($table->getIndex('index_boolean')->isUnique());
diff --git a/tests/lib/DB/testschema.xml b/tests/lib/DB/testschema.xml
index 5f449c936d9f418e098f87438db66a7771de3bed..a2b01d8259e45946764a1e0c9a1a892380897eda 100644
--- a/tests/lib/DB/testschema.xml
+++ b/tests/lib/DB/testschema.xml
@@ -13,7 +13,7 @@
 
 		<declaration>
 			<field>
-				<name>integerfield</name>
+				<name>id</name>
 				<type>integer</type>
 				<default>0</default>
 				<notnull>true</notnull>
@@ -21,6 +21,13 @@
 				<length>4</length>
 				<autoincrement>1</autoincrement>
 			</field>
+			<field>
+				<name>integerfield</name>
+				<type>integer</type>
+				<default>0</default>
+				<notnull>true</notnull>
+				<length>4</length>
+			</field>
 			<field>
 				<name>integerfield_default</name>
 				<type>integer</type>
@@ -37,7 +44,7 @@
 			</field>
 			<field>
 				<name>clobfield</name>
-				<type>clob</type>
+				<type>text</type>
 			</field>
 			<field>
 				<name>booleanfield</name>
@@ -64,6 +71,15 @@
 				<name>index_primary</name>
 				<primary>true</primary>
 				<unique>true</unique>
+				<field>
+					<name>id</name>
+					<sorting>ascending</sorting>
+				</field>
+			</index>
+
+			<index>
+				<name>index_integerfield</name>
+				<unique>true</unique>
 				<field>
 					<name>integerfield</name>
 					<sorting>ascending</sorting>
diff --git a/version.php b/version.php
index 280a04eec0173847667f49f304fdcb95163d6181..2915ada69dce6b0e1878a69409c0eeb9b5815321 100644
--- a/version.php
+++ b/version.php
@@ -29,7 +29,7 @@
 // between betas, final and RCs. This is _not_ the public version number. Reset minor/patchlevel
 // when updating major/minor version number.
 
-$OC_Version = [21, 0, 0, 2];
+$OC_Version = [21, 0, 0, 6];
 
 // The human readable string
 $OC_VersionString = '21.0.0 alpha';