diff --git a/lib/private/Files/External/Auth/Password/SessionCredentials.php b/lib/private/Files/External/Auth/Password/SessionCredentials.php
index ff4e0b875f3c..fa3e982f8ed3 100644
--- a/lib/private/Files/External/Auth/Password/SessionCredentials.php
+++ b/lib/private/Files/External/Auth/Password/SessionCredentials.php
@@ -75,7 +75,11 @@ public function manipulateStorageConfig(IStorageConfig &$storage, IUser $user =
 		}
 
 		$credentials = \json_decode($this->crypto->decrypt($encrypted), true);
-		$storage->setBackendOption('user', $this->session->get('loginname'));
+		if ($user !== null) {
+			$storage->setBackendOption('user', $user->getUserName());
+		} else {
+			$storage->setBackendOption('user', $this->session->get('loginname'));
+		}
 		$storage->setBackendOption('password', $credentials['password']);
 	}
 
diff --git a/lib/private/Files/External/ConfigAdapter.php b/lib/private/Files/External/ConfigAdapter.php
index 9942361911cf..c50ed726b85b 100644
--- a/lib/private/Files/External/ConfigAdapter.php
+++ b/lib/private/Files/External/ConfigAdapter.php
@@ -36,6 +36,8 @@
 use OC\Files\Storage\FailedStorage;
 use OCP\Files\StorageNotAvailableException;
 use OCP\IConfig;
+use OCP\Files\ObjectStore\IObjectStore;
+use OCP\ISession;
 
 /**
  * Make the old files_external config work with the new public mount config api
@@ -51,6 +53,9 @@ class ConfigAdapter implements IMountProvider {
 	/** @var IUserGlobalStoragesService */
 	private $userGlobalStoragesService;
 
+	/** @var ISession */
+	private $session;
+
 	/**
 	 * @param IUserStoragesService $userStoragesService
 	 * @param IUserGlobalStoragesService $userGlobalStoragesService
@@ -58,11 +63,13 @@ class ConfigAdapter implements IMountProvider {
 	public function __construct(
 		IConfig $config,
 		IUserStoragesService $userStoragesService,
-		IUserGlobalStoragesService $userGlobalStoragesService
+		IUserGlobalStoragesService $userGlobalStoragesService,
+		ISession $session
 	) {
 		$this->config = $config;
 		$this->userStoragesService = $userStoragesService;
 		$this->userGlobalStoragesService = $userGlobalStoragesService;
+		$this->session = $session;
 	}
 
 	/**
@@ -74,7 +81,7 @@ public function __construct(
 	private function prepareStorageConfig(IStorageConfig &$storage, IUser $user) {
 		foreach ($storage->getBackendOptions() as $option => $value) {
 			$storage->setBackendOption($option, $this->setUserVars(
-				$user->getUID(), $value
+				$user->getUserName(), $value
 			));
 		}
 
diff --git a/lib/private/Files/External/LegacyUtil.php b/lib/private/Files/External/LegacyUtil.php
index 553679e6dc3b..49b384177266 100644
--- a/lib/private/Files/External/LegacyUtil.php
+++ b/lib/private/Files/External/LegacyUtil.php
@@ -66,7 +66,7 @@ public static function getAbsoluteMountPoints($uid) {
 			$mountPoint = '/'.$uid.'/files'.$storage->getMountPoint();
 			$mountEntry = self::prepareMountPointEntry($storage, false);
 			foreach ($mountEntry['options'] as &$option) {
-				$option = self::setUserVars($uid, $option);
+				$option = self::setUserVars($user->getUserName(), $option);
 			}
 			$mountPoints[$mountPoint] = $mountEntry;
 		}
@@ -75,7 +75,7 @@ public static function getAbsoluteMountPoints($uid) {
 			$mountPoint = '/'.$uid.'/files'.$storage->getMountPoint();
 			$mountEntry = self::prepareMountPointEntry($storage, true);
 			foreach ($mountEntry['options'] as &$option) {
-				$option = self::setUserVars($uid, $option);
+				$option = self::setUserVars($user->getUserName(), $option);
 			}
 			$mountPoints[$mountPoint] = $mountEntry;
 		}
@@ -190,8 +190,11 @@ public static function getBackendStatus($class, $options, $isPersonal, $testOnly
 		if (self::$skipTest) {
 			return StorageNotAvailableException::STATUS_SUCCESS;
 		}
-		foreach ($options as $key => $option) {
-			$options[$key] = self::setUserVars(\OCP\User::getUser(), $option);
+		$user = \OC::$server->getUserSession()->getUser();
+		if ($user) {
+			foreach ($options as $key => $option) {
+				$options[$key] = self::setUserVars($user->getUserName(), $option);
+			}
 		}
 		if (\class_exists($class)) {
 			try {
diff --git a/lib/private/Server.php b/lib/private/Server.php
index 087972d9f3c4..cb4fccfdaaf9 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -632,7 +632,8 @@ public function __construct($webRoot, \OC\Config $config) {
 				$manager->registerProvider(new \OC\Files\External\ConfigAdapter(
 					$c->query('AllConfig'),
 					$c->query('UserStoragesService'),
-					$c->query('UserGlobalStoragesService')
+					$c->query('UserGlobalStoragesService'),
+					$c->getSession()
 				));
 			}
 
diff --git a/lib/private/User/RemoteUser.php b/lib/private/User/RemoteUser.php
index f7c138d00ce0..ca9e36992794 100644
--- a/lib/private/User/RemoteUser.php
+++ b/lib/private/User/RemoteUser.php
@@ -49,6 +49,19 @@ public function getUID() {
 		return $this->userId;
 	}
 
+	/**
+	 * @inheritdoc
+	 */
+	public function getUserName() {
+		return $this->getUID();
+	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public function setUserName($userName) {
+	}
+
 	/**
 	 * @inheritdoc
 	 */
diff --git a/lib/private/User/SyncService.php b/lib/private/User/SyncService.php
index 8575bd014348..628208d625be 100644
--- a/lib/private/User/SyncService.php
+++ b/lib/private/User/SyncService.php
@@ -24,11 +24,13 @@
 use OCP\AppFramework\Db\DoesNotExistException;
 use OCP\IConfig;
 use OCP\ILogger;
+use OCP\PreConditionNotMetException;
 use OCP\User\IProvidesDisplayNameBackend;
 use OCP\User\IProvidesEMailBackend;
 use OCP\User\IProvidesExtendedSearchBackend;
 use OCP\User\IProvidesHomeBackend;
 use OCP\User\IProvidesQuotaBackend;
+use OCP\User\IProvidesUserNameBackend;
 use OCP\UserInterface;
 use OCP\AppFramework\Db\MultipleObjectsReturnedException;
 
@@ -292,6 +294,30 @@ private function syncDisplayName(Account $a, UserInterface $backend) {
 		}
 	}
 
+	/**
+	 * TODO store username in account table instead of user preferences
+	 *
+	 * @param Account $a
+	 * @param UserInterface $backend
+	 */
+	private function syncUserName(Account $a, UserInterface $backend) {
+		$uid = $a->getUserId();
+		if ($backend instanceof IProvidesUserNameBackend) {
+			$userName = $backend->getUserName($uid);
+			$currentUserName = $this->config->getUserValue($uid, 'core', 'username', null);
+			if ($userName !== $currentUserName) {
+				try {
+					$this->config->setUserValue($uid, 'core', 'username', $userName);
+				} catch (PreConditionNotMetException $e) {
+					// ignore, because precondition is empty
+				}
+				$this->logger->debug(
+					"Setting userName for <$uid> from <$currentUserName> to <$userName>", ['app' => self::class]
+				);
+			}
+		}
+	}
+
 	/**
 	 * @param Account $a
 	 * @param UserInterface $backend
@@ -322,6 +348,7 @@ public function syncAccount(Account $a, UserInterface $backend) {
 		$this->syncQuota($a, $backend);
 		$this->syncHome($a, $backend);
 		$this->syncDisplayName($a, $backend);
+		$this->syncUserName($a, $backend);
 		$this->syncSearchTerms($a, $backend);
 		return $a;
 	}
diff --git a/lib/private/User/User.php b/lib/private/User/User.php
index f8307ab2a7a5..e09620d599c9 100644
--- a/lib/private/User/User.php
+++ b/lib/private/User/User.php
@@ -42,6 +42,7 @@
 use OCP\IConfig;
 use OCP\IUserBackend;
 use OCP\IUserSession;
+use OCP\PreConditionNotMetException;
 use OCP\User\IChangePasswordBackend;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\EventDispatcher\GenericEvent;
@@ -123,6 +124,35 @@ public function getUID() {
 		return $this->account->getUserId();
 	}
 
+	/**
+	 * get the user name
+	 * TODO move username to account table
+	 *
+	 * @return string
+	 */
+	public function getUserName() {
+		$uid = $this->getUID();
+		return $this->config->getUserValue($uid, 'core', 'username', $uid);
+	}
+
+	/**
+	 * set the user name
+	 * TODO move username to account table
+	 *
+	 * @param string $userName
+	 */
+	public function setUserName($userName) {
+		$currentUserName = $this->getUserName();
+		if ($userName !== $currentUserName) {
+			$uid = $this->getUID();
+			try {
+				$this->config->setUserValue($uid, 'core', 'username', $userName);
+			} catch (PreConditionNotMetException $e) {
+				// ignore, because precondition is empty
+			}
+		}
+	}
+
 	/**
 	 * get the display name for the user, if no specific display name is set it will fallback to the user id
 	 *
diff --git a/lib/public/IUser.php b/lib/public/IUser.php
index 89c536ba45ee..25d011df7c7b 100644
--- a/lib/public/IUser.php
+++ b/lib/public/IUser.php
@@ -41,6 +41,22 @@ interface IUser {
 	 */
 	public function getUID();
 
+	/**
+	 * get the user name
+	 *
+	 * @return string
+	 * @since 10.0.10
+	 */
+	public function getUserName();
+
+	/**
+	 * set the user name
+	 *
+	 * @param string $userName
+	 * @since 10.0.10
+	 */
+	public function setUserName($userName);
+
 	/**
 	 * get the display name for the user, if no specific display name is set it will fallback to the user id
 	 *
diff --git a/lib/public/User/IProvidesUserNameBackend.php b/lib/public/User/IProvidesUserNameBackend.php
new file mode 100644
index 000000000000..afa6a8c2eb6b
--- /dev/null
+++ b/lib/public/User/IProvidesUserNameBackend.php
@@ -0,0 +1,41 @@
+<?php
+/**
+ * @author Jörn Friedrich Dreyer <jfd@butonic.de>
+ *
+ * @copyright Copyright (c) 2018, ownCloud GmbH
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+// use OCP namespace for all classes that are considered public.
+// This means that they should be used by apps instead of the internal ownCloud classes
+namespace OCP\User;
+
+/**
+ * Interface IProvidesUserNameBackend
+ *
+ * @package OCP\User
+ * @since 10.0
+ */
+interface IProvidesUserNameBackend {
+
+	/**
+	 * get display name of the user
+	 * @param string $uid user ID of the user
+	 * @return string user name
+	 * @since 10.0.10
+	 */
+	public function getUserName($uid);
+}
diff --git a/tests/lib/Files/External/Auth/Password/SessionCredentialsTest.php b/tests/lib/Files/External/Auth/Password/SessionCredentialsTest.php
new file mode 100644
index 000000000000..47cb8aebd75f
--- /dev/null
+++ b/tests/lib/Files/External/Auth/Password/SessionCredentialsTest.php
@@ -0,0 +1,124 @@
+<?php
+/**
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2018, ownCloud GmbH
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace Test\Files\External\Auth\Password;
+
+use OC\Files\External\Auth\Password\SessionCredentials;
+use OCP\ISession;
+use OCP\Security\ICrypto;
+use OCP\Files\External\IStorageConfig;
+use OCP\IUser;
+
+class SessionCredentialsTest extends \Test\TestCase {
+
+	/** @var SessionCredentials | \PHPUnit_Framework_MockObject_MockObject */
+	private $authMech;
+
+	/** @var ISession | \PHPUnit_Framework_MockObject_MockObject */
+	private $session;
+
+	/** @var ICrypto | \PHPUnit_Framework_MockObject_MockObject */
+	private $crypto;
+
+	public function setUp() {
+		parent::setUp();
+		$this->session = $this->createMock(ISession::class);
+		$this->crypto = $this->createMock(ICrypto::class);
+		$this->authMech = new SessionCredentials(
+			$this->session,
+			$this->crypto
+		);
+	}
+
+	public function tearDown() {
+		\OC_Hook::clear('OC_User', 'post_login');
+		parent::tearDown();
+	}
+
+	public function sessionDataProvider() {
+		return [
+			[
+				[
+					['password::sessioncredentials/credentials', 'encrypted_stuff'],
+					['loginname', 'login1'],
+				],
+				null,
+				'login1'
+			],
+			[
+				[
+					['password::sessioncredentials/credentials', 'encrypted_stuff'],
+				],
+				'altlogin2',
+				'altlogin2'
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider sessionDataProvider
+	 */
+	public function testManipulateStorageConfigSetsBackendOptions($sessionData, $userName, $expectedLogin) {
+		$storageConfig = $this->createMock(IStorageConfig::class);
+		if ($userName !== null) {
+			$user = $this->createMock(IUser::class);
+			$user->expects($this->once())
+				->method('getUserName')
+				->willReturn($userName);
+		} else {
+			$user = null;
+		}
+
+		$this->session->method('get')->will($this->returnValueMap($sessionData));
+		$this->session->method('exists')->will($this->returnCallback(function ($key) {
+			return $this->session->get($key) !== null;
+		}));
+
+		$this->crypto->expects($this->once())
+			->method('decrypt')
+			->with('encrypted_stuff')
+			->willReturn('{"user":"user1","password":"pw"}');
+
+		$storageConfig->expects($this->at(0))
+			->method('setBackendOption')
+			->with('user', $expectedLogin);
+		$storageConfig->expects($this->at(1))
+			->method('setBackendOption')
+			->with('password', 'pw');
+
+		$this->authMech->manipulateStorageConfig($storageConfig, $user);
+	}
+
+	/**
+	 * @expectedException \OCP\Files\External\InsufficientDataForMeaningfulAnswerException
+	 */
+	public function testManipulateStorageConfigFailsWhenEmptyCredentials() {
+		$storageConfig = $this->createMock(IStorageConfig::class);
+		$user = $this->createMock(IUser::class);
+
+		$this->session->expects($this->once())
+			->method('get')
+			->with('password::sessioncredentials/credentials')
+			->willReturn(null);
+
+		$this->authMech->manipulateStorageConfig($storageConfig, $user);
+	}
+}
diff --git a/tests/lib/Files/External/ConfigAdapterTest.php b/tests/lib/Files/External/ConfigAdapterTest.php
index eb2f78d05429..050aebe91a14 100644
--- a/tests/lib/Files/External/ConfigAdapterTest.php
+++ b/tests/lib/Files/External/ConfigAdapterTest.php
@@ -32,10 +32,12 @@
 use OCP\Files\External\Service\IUserStoragesService;
 use OCP\IConfig;
 use OCP\IUser;
+use OCP\ISession;
+use OC\Files\External\StorageConfig;
 
 class ConfigAdapterTest extends \Test\TestCase {
 
-	/** @var \OCP\IConfig */
+	/** @var \OCP\IConfig | \PHPUnit_Framework_MockObject_MockObject */
 	private $config;
 
 	/** @var IUserStoragesService */
@@ -44,42 +46,38 @@ class ConfigAdapterTest extends \Test\TestCase {
 	/** @var IUserGlobalStoragesService */
 	private $userGlobalStoragesService;
 
-	/** @var IUser **/
+	/** @var IUser | \PHPUnit_Framework_MockObject_MockObject **/
 	private $user;
 
+	/** @var ISession | \PHPUnit_Framework_MockObject_MockObject **/
+	private $session;
+
+	/** @var int */
+	private $configId;
+
 	protected function setUp() {
 		$this->config = $this->createMock(IConfig::class);
 		$this->userStoragesService = $this->createMock(UserStoragesService::class);
 		$this->userGlobalStoragesService = $this->createMock(UserGlobalStoragesService::class);
+		$this->session = $this->createMock(ISession::class);
 		$this->user = $this->createMock(IUser::class);
 		$this->user->expects($this->any())
 			->method('getUID')
 			->willReturn('user1');
+		$this->configId = 0;
 	}
 
-	private function createStorageConfig($mountPoint, $mountOptions) {
+	private function createStorageConfig($mountPoint, $mountOptions, $storageOptions) {
 		$auth = $this->createMock(AuthMechanism::class);
 		$backend = $this->createMock(Backend::class);
-		$config = $this->createMock(IStorageConfig::class);
-
-		$config->expects($this->any())
-			->method('getBackendOptions')
-			->willReturn([]);
-		$config->expects($this->any())
-			->method('getBackendOption')
-			->willReturn(null);
-		$config->expects($this->any())
-			->method('getAuthMechanism')
-			->willReturn($auth);
-		$config->expects($this->any())
-			->method('getBackend')
-			->willReturn($backend);
-		$config->expects($this->any())
-			->method('getMountPoint')
-			->willReturn($mountPoint);
-		$config->expects($this->any())
-			->method('getMountOptions')
-			->willReturn($mountOptions);
+		$this->configId++;
+		$config = new StorageConfig($this->configId);
+
+		$config->setMountPoint($mountPoint);
+		$config->setMountOptions($mountOptions);
+		$config->setBackendOptions($storageOptions);
+		$config->setAuthMechanism($auth);
+		$config->setBackend($backend);
 
 		$auth->expects($this->once())
 			->method('manipulateStorageConfig')
@@ -130,15 +128,16 @@ private function getMountsForUser($globalStorages, $personalStorages) {
 		$configAdapter = new ConfigAdapter(
 			$this->config,
 			$this->userStoragesService,
-			$this->userGlobalStoragesService
+			$this->userGlobalStoragesService,
+			$this->session
 		);
 
 		return $configAdapter->getMountsForUser($this->user, $storageFactory);
 	}
 
 	public function testGetPersonalMounts() {
-		$storage1 = $this->createStorageConfig('/mount1', ['test_value' => true]);
-		$storage2 = $this->createStorageConfig('/globalmount1', ['test_value2' => 'abc']);
+		$storage1 = $this->createStorageConfig('/mount1', ['test_value' => true], ['backend_option' => 'abc']);
+		$storage2 = $this->createStorageConfig('/globalmount1', ['test_value2' => 'abc'], ['backend_option' => 'def']);
 
 		$result = $this->getMountsForUser([$storage2], [$storage1]);
 
@@ -173,8 +172,8 @@ public function testGetPersonalMountSharingOption($isSharingAllowed, $expectedVa
 				['core', 'allow_user_mount_sharing', 'yes', $isSharingAllowed ? 'yes' : 'no']
 			]));
 
-		$storage1 = $this->createStorageConfig('/mount1', ['enable_sharing' => true]);
-		$storage2 = $this->createStorageConfig('/globalmount1', ['enable_sharing' => true]);
+		$storage1 = $this->createStorageConfig('/mount1', ['enable_sharing' => true], ['backend_option' => 'abc']);
+		$storage2 = $this->createStorageConfig('/globalmount1', ['enable_sharing' => true], ['backend_option' => 'abc']);
 
 		$result = $this->getMountsForUser([$storage2], [$storage1]);
 
@@ -188,4 +187,36 @@ public function testGetPersonalMountSharingOption($isSharingAllowed, $expectedVa
 		$options = $mount->getOptions();
 		$this->assertTrue($options['enable_sharing']);
 	}
+
+	public function testGetPersonalMountsUserPlaceholder() {
+		$this->user->expects($this->any())
+			->method('getUserName')
+			->willReturn('user1');
+		
+		$storage1 = $this->createStorageConfig('/mount1', [], ['backend_option' => '$user']);
+		$storage2 = $this->createStorageConfig('/globalmount1', [], ['backend_option' => '$user']);
+
+		$result = $this->getMountsForUser([$storage2], [$storage1]);
+
+		$this->assertCount(2, $result);
+
+		$this->assertEquals('user1', $storage1->getBackendOption('backend_option'));
+		$this->assertEquals('user1', $storage2->getBackendOption('backend_option'));
+	}
+
+	public function testGetPersonalMountsUserPlaceholderAltLogin() {
+		$this->user->expects($this->any())
+			->method('getUserName')
+			->willReturn('altlogin1');
+
+		$storage1 = $this->createStorageConfig('/mount1', [], ['backend_option' => '$user']);
+		$storage2 = $this->createStorageConfig('/globalmount1', [], ['backend_option' => '$user']);
+
+		$result = $this->getMountsForUser([$storage2], [$storage1]);
+
+		$this->assertCount(2, $result);
+
+		$this->assertEquals('altlogin1', $storage1->getBackendOption('backend_option'));
+		$this->assertEquals('altlogin1', $storage2->getBackendOption('backend_option'));
+	}
 }
diff --git a/tests/lib/User/SyncServiceTest.php b/tests/lib/User/SyncServiceTest.php
index d9aed977686e..6c7ba5a249bb 100644
--- a/tests/lib/User/SyncServiceTest.php
+++ b/tests/lib/User/SyncServiceTest.php
@@ -34,6 +34,7 @@
 use OCP\ILogger;
 use OCP\User\IProvidesHomeBackend;
 use OCP\User\IProvidesQuotaBackend;
+use OCP\User\IProvidesUserNameBackend;
 use OCP\UserInterface;
 use Test\TestCase;
 
@@ -276,4 +277,27 @@ public function testSyncQuota($backendProvidesQuota, $backendQuota, $preferences
 		$s = new SyncService($this->config, $this->logger, $this->mapper);
 		static::invokePrivate($s, 'syncQuota', [$a, $backend]);
 	}
+
+	public function testSyncUserName() {
+		$a = $this->createMock(Account::class);
+		$a->method('__call')->with('getUserId')->willReturn('user1');
+
+		/** @var UserInterface | IProvidesUserNameBackend | \PHPUnit_Framework_MockObject_MockObject $backend */
+		$backend = $this->createMock([UserInterface::class, IProvidesUserNameBackend::class]);
+		$backend->expects($this->once())
+			->method('getUserName')
+			->willReturn('userName1');
+
+		$this->config->expects($this->once())
+			->method('getUserValue')
+			->with('user1', 'core', 'username', null)
+			->willReturn(null);
+		
+		$this->config->expects($this->once())
+			->method('setUserValue')
+			->with('user1', 'core', 'username', 'userName1');
+
+		$s = new SyncService($this->config, $this->logger, $this->mapper);
+		static::invokePrivate($s, 'syncUserName', [$a, $backend]);
+	}
 }
diff --git a/tests/lib/User/UserTest.php b/tests/lib/User/UserTest.php
index 95a4afc62e12..5f3cd6d7e333 100644
--- a/tests/lib/User/UserTest.php
+++ b/tests/lib/User/UserTest.php
@@ -86,6 +86,43 @@ public function testDisplayNameEmpty() {
 		$this->assertEquals('foo', $this->user->getDisplayName());
 	}
 
+	public function testGetUserName() {
+		$this->config->expects($this->once())
+			->method('getUserValue')
+			->with('foo', 'core', 'username')
+			->willReturn('fooName');
+		$this->assertEquals('fooName', $this->user->getUserName());
+	}
+
+	public function testGetUserNameFallback() {
+		$this->config->expects($this->once())
+			->method('getUserValue')
+			->with('foo', 'core', 'username')
+			->willReturn('foo');
+		$this->assertEquals('foo', $this->user->getUserName());
+	}
+
+	public function testSetUserName() {
+		$this->config->expects($this->at(0))
+			->method('getUserValue')
+			->with('foo', 'core', 'username', 'foo')
+			->willReturn('foo');
+		$this->config->expects($this->at(1))
+			->method('setUserValue')
+			->with('foo', 'core', 'username', 'fooName');
+		$this->user->setUserName('fooName');
+	}
+
+	public function testSetUserNameSame() {
+		$this->config->expects($this->once())
+			->method('getUserValue')
+			->with('foo', 'core', 'username', 'foo')
+			->willReturn('foo');
+		$this->config->expects($this->never())
+			->method('setUserValue');
+		$this->user->setUserName('foo');
+	}
+
 	public function testSetPassword() {
 		$this->config->expects($this->once())
 			->method('deleteUserValue')