feat(dav): update a principal's schedule-default-calendar-URL

Signed-off-by: Richard Steinmetz <richard@steinmetz.cloud>

7 files changed, 341 insertions, 9 deletions

diff --git a/apps/dav/lib/CalDAV/Schedule/Plugin.php b/apps/dav/lib/CalDAV/Schedule/Plugin.php
index 232ee607c94..2ccecc8131c 100644
--- a/apps/dav/lib/CalDAV/Schedule/Plugin.php
+++ b/apps/dav/lib/CalDAV/Schedule/Plugin.php
@@ -95,6 +95,13 @@ class Plugin extends \Sabre\CalDAV\Schedule\Plugin {
 		$server->on('propFind', [$this, 'propFindDefaultCalendarUrl'], 90);
 		$server->on('afterWriteContent', [$this, 'dispatchSchedulingResponses']);
 		$server->on('afterCreateFile', [$this, 'dispatchSchedulingResponses']);
+
+		// We allow mutating the default calendar URL through the CustomPropertiesBackend
+		// (oc_properties table)
+		$server->protectedProperties = array_filter(
+			$server->protectedProperties,
+			static fn (string $property) => $property !== self::SCHEDULE_DEFAULT_CALENDAR_URL,
+		);
 	}
 
 	/**
diff --git a/apps/dav/lib/Connector/Sabre/Principal.php b/apps/dav/lib/Connector/Sabre/Principal.php
index 9d9cfbe43cb..c6f9fe3affc 100644
--- a/apps/dav/lib/Connector/Sabre/Principal.php
+++ b/apps/dav/lib/Connector/Sabre/Principal.php
@@ -260,6 +260,7 @@ class Principal implements BackendInterface {
 	 * @return int
 	 */
 	public function updatePrincipal($path, PropPatch $propPatch) {
+		// Updating schedule-default-calendar-URL is handled in CustomPropertiesBackend
 		return 0;
 	}
 
diff --git a/apps/dav/lib/Connector/Sabre/ServerFactory.php b/apps/dav/lib/Connector/Sabre/ServerFactory.php
index 113cd8a8c23..758951c42ff 100644
--- a/apps/dav/lib/Connector/Sabre/ServerFactory.php
+++ b/apps/dav/lib/Connector/Sabre/ServerFactory.php
@@ -188,6 +188,7 @@ class ServerFactory {
 				$server->addPlugin(
 					new \Sabre\DAV\PropertyStorage\Plugin(
 						new \OCA\DAV\DAV\CustomPropertiesBackend(
+							$server,
 							$objectTree,
 							$this->databaseConnection,
 							$this->userSession->getUser()
diff --git a/apps/dav/lib/DAV/CustomPropertiesBackend.php b/apps/dav/lib/DAV/CustomPropertiesBackend.php
index e76a71aec63..48872048ea8 100644
--- a/apps/dav/lib/DAV/CustomPropertiesBackend.php
+++ b/apps/dav/lib/DAV/CustomPropertiesBackend.php
@@ -6,6 +6,7 @@
  * @author Georg Ehrke <oc.list@georgehrke.com>
  * @author Robin Appelman <robin@icewind.nl>
  * @author Thomas Müller <thomas.mueller@tmit.eu>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
  *
  * @license AGPL-3.0
  *
@@ -31,11 +32,19 @@ use OCA\DAV\Connector\Sabre\FilesPlugin;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
 use OCP\IUser;
+use Sabre\CalDAV\ICalendar;
+use Sabre\DAV\Exception as DavException;
 use Sabre\DAV\PropertyStorage\Backend\BackendInterface;
 use Sabre\DAV\PropFind;
 use Sabre\DAV\PropPatch;
+use Sabre\DAV\Server;
 use Sabre\DAV\Tree;
 use Sabre\DAV\Xml\Property\Complex;
+use Sabre\DAV\Xml\Property\Href;
+use Sabre\DAV\Xml\Property\LocalHref;
+use Sabre\Xml\ParseException;
+use Sabre\Xml\Service as XmlService;
+
 use function array_intersect;
 
 class CustomPropertiesBackend implements BackendInterface {
@@ -59,6 +68,11 @@ class CustomPropertiesBackend implements BackendInterface {
 	public const PROPERTY_TYPE_OBJECT = 3;
 
 	/**
+	 * Value is stored as a {DAV:}href string.
+	 */
+	public const PROPERTY_TYPE_HREF = 4;
+
+	/**
 	 * Ignored properties
 	 *
 	 * @var string[]
@@ -105,6 +119,15 @@ class CustomPropertiesBackend implements BackendInterface {
 	 */
 	private const PUBLISHED_READ_ONLY_PROPERTIES = [
 		'{urn:ietf:params:xml:ns:caldav}calendar-availability',
+		'{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL',
+	];
+
+	/**
+	 * Map of custom XML elements to parse when trying to deserialize an instance of
+	 * \Sabre\DAV\Xml\Property\Complex to find a more specialized PROPERTY_TYPE_*
+	 */
+	private const COMPLEX_XML_ELEMENT_MAP = [
+		'{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => Href::class,
 	];
 
 	/**
@@ -129,19 +152,29 @@ class CustomPropertiesBackend implements BackendInterface {
 	 */
 	private $userCache = [];
 
+	private Server $server;
+	private XmlService $xmlService;
+
 	/**
 	 * @param Tree $tree node tree
 	 * @param IDBConnection $connection database connection
 	 * @param IUser $user owner of the tree and properties
 	 */
 	public function __construct(
+		Server $server,
 		Tree $tree,
 		IDBConnection $connection,
 		IUser $user,
 	) {
+		$this->server = $server;
 		$this->tree = $tree;
 		$this->connection = $connection;
 		$this->user = $user;
+		$this->xmlService = new XmlService();
+		$this->xmlService->elementMap = array_merge(
+			$this->xmlService->elementMap,
+			self::COMPLEX_XML_ELEMENT_MAP,
+		);
 	}
 
 	/**
@@ -199,6 +232,21 @@ class CustomPropertiesBackend implements BackendInterface {
 			}
 		}
 
+		// substr of principals/users/ => path is a user principal
+		// two '/' => this a principal collection (and not some child object)
+		if (str_starts_with($path, 'principals/users/') && substr_count($path, '/') === 2) {
+			$allRequestedProps = $propFind->getRequestedProperties();
+			$customProperties = [
+				'{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL',
+			];
+
+			foreach ($customProperties as $customProperty) {
+				if (in_array($customProperty, $allRequestedProps, true)) {
+					$requestedProps[] = $customProperty;
+				}
+			}
+		}
+
 		if (empty($requestedProps)) {
 			return;
 		}
@@ -211,9 +259,19 @@ class CustomPropertiesBackend implements BackendInterface {
 		// First fetch the published properties (set by another user), then get the ones set by
 		// the current user. If both are set then the latter as priority.
 		foreach ($this->getPublishedProperties($path, $requestedProps) as $propName => $propValue) {
+			try {
+				$this->validateProperty($path, $propName, $propValue);
+			} catch (DavException $e) {
+				continue;
+			}
 			$propFind->set($propName, $propValue);
 		}
 		foreach ($this->getUserProperties($path, $requestedProps) as $propName => $propValue) {
+			try {
+				$this->validateProperty($path, $propName, $propValue);
+			} catch (DavException $e) {
+				continue;
+			}
 			$propFind->set($propName, $propValue);
 		}
 	}
@@ -265,6 +323,30 @@ class CustomPropertiesBackend implements BackendInterface {
 	}
 
 	/**
+	 * Validate the value of a property. Will throw if a value is invalid.
+	 *
+	 * @throws DavException The value of the property is invalid
+	 */
+	private function validateProperty(string $path, string $propName, mixed $propValue): void {
+		switch ($propName) {
+			case '{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL':
+				/** @var Href $propValue */
+				$href = $propValue->getHref();
+				if ($href === null) {
+					throw new DavException('Href is empty');
+				}
+
+				// $path is the principal here as this prop is only set on principals
+				$node = $this->tree->getNodeForPath($href);
+				if (!($node instanceof ICalendar) || $node->getOwner() !== $path) {
+					throw new DavException('No such calendar');
+				}
+
+				break;
+		}
+	}
+
+	/**
 	 * @param string $path
 	 * @param string[] $requestedProperties
 	 *
@@ -393,7 +475,11 @@ class CustomPropertiesBackend implements BackendInterface {
 							->executeStatement();
 					}
 				} else {
-					[$value, $valueType] = $this->encodeValueForDatabase($propertyValue);
+					[$value, $valueType] = $this->encodeValueForDatabase(
+						$path,
+						$propertyName,
+						$propertyValue,
+					);
 					$dbParameters['propertyValue'] = $value;
 					$dbParameters['valueType'] = $valueType;
 
@@ -436,15 +522,38 @@ class CustomPropertiesBackend implements BackendInterface {
 	}
 
 	/**
-	 * @param mixed $value
-	 * @return array
+	 * @throws ParseException If parsing a \Sabre\DAV\Xml\Property\Complex value fails
+	 * @throws DavException If the property value is invalid
 	 */
-	private function encodeValueForDatabase($value): array {
+	private function encodeValueForDatabase(string $path, string $name, mixed $value): array {
+		// Try to parse a more specialized property type first
+		if ($value instanceof Complex) {
+			$xml = $this->xmlService->write($name, [$value], $this->server->getBaseUri());
+			$value = $this->xmlService->parse($xml, $this->server->getBaseUri()) ?? $value;
+		}
+
+		if ($name === '{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL') {
+			$value = $this->encodeDefaultCalendarUrl($value);
+		}
+
+		try {
+			$this->validateProperty($path, $name, $value);
+		} catch (DavException $e) {
+			throw new DavException(
+				"Property \"$name\" has an invalid value: " . $e->getMessage(),
+				0,
+				$e,
+			);
+		}
+
 		if (is_scalar($value)) {
 			$valueType = self::PROPERTY_TYPE_STRING;
 		} elseif ($value instanceof Complex) {
 			$valueType = self::PROPERTY_TYPE_XML;
 			$value = $value->getXml();
+		} elseif ($value instanceof Href) {
+			$valueType = self::PROPERTY_TYPE_HREF;
+			$value = $value->getHref();
 		} else {
 			$valueType = self::PROPERTY_TYPE_OBJECT;
 			$value = serialize($value);
@@ -459,6 +568,8 @@ class CustomPropertiesBackend implements BackendInterface {
 		switch ($valueType) {
 			case self::PROPERTY_TYPE_XML:
 				return new Complex($value);
+			case self::PROPERTY_TYPE_HREF:
+				return new Href($value);
 			case self::PROPERTY_TYPE_OBJECT:
 				return unserialize($value);
 			case self::PROPERTY_TYPE_STRING:
@@ -467,6 +578,26 @@ class CustomPropertiesBackend implements BackendInterface {
 		}
 	}
 
+	private function encodeDefaultCalendarUrl(Href $value): Href {
+		$href = $value->getHref();
+		if ($href === null) {
+			return $value;
+		}
+
+		if (!str_starts_with($href, '/')) {
+			return $value;
+		}
+
+		try {
+			// Build path relative to the dav base URI to be used later to find the node
+			$value = new LocalHref($this->server->calculateUri($href) . '/');
+		} catch (DavException\Forbidden) {
+			// Not existing calendars will be handled later when the value is validated
+		}
+
+		return $value;
+	}
+
 	private function createDeleteQuery(): IQueryBuilder {
 		$deleteQuery = $this->connection->getQueryBuilder();
 		$deleteQuery->delete('properties')
diff --git a/apps/dav/lib/Server.php b/apps/dav/lib/Server.php
index 3c7e0936735..deee381d24c 100644
--- a/apps/dav/lib/Server.php
+++ b/apps/dav/lib/Server.php
@@ -276,6 +276,7 @@ class Server {
 				$this->server->addPlugin(
 					new \Sabre\DAV\PropertyStorage\Plugin(
 						new CustomPropertiesBackend(
+							$this->server,
 							$this->server->tree,
 							\OC::$server->getDatabaseConnection(),
 							\OC::$server->getUserSession()->getUser()
diff --git a/apps/dav/tests/unit/Connector/Sabre/CustomPropertiesBackendTest.php b/apps/dav/tests/unit/Connector/Sabre/CustomPropertiesBackendTest.php
index 395c4a6a779..636fd0d2d8d 100644
--- a/apps/dav/tests/unit/Connector/Sabre/CustomPropertiesBackendTest.php
+++ b/apps/dav/tests/unit/Connector/Sabre/CustomPropertiesBackendTest.php
@@ -87,6 +87,7 @@ class CustomPropertiesBackendTest extends \Test\TestCase {
 			->willReturn($userId);
 
 		$this->plugin = new \OCA\DAV\DAV\CustomPropertiesBackend(
+			$this->server,
 			$this->tree,
 			\OC::$server->getDatabaseConnection(),
 			$this->user
diff --git a/apps/dav/tests/unit/DAV/CustomPropertiesBackendTest.php b/apps/dav/tests/unit/DAV/CustomPropertiesBackendTest.php
index 2c8a55d3da1..b81d7f24ae4 100644
--- a/apps/dav/tests/unit/DAV/CustomPropertiesBackendTest.php
+++ b/apps/dav/tests/unit/DAV/CustomPropertiesBackendTest.php
@@ -8,6 +8,7 @@
  * @author Morris Jobke <hey@morrisjobke.de>
  * @author Robin Appelman <robin@icewind.nl>
  * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
  *
  * @license GNU AGPL version 3 or any later version
  *
@@ -28,17 +29,29 @@
 namespace OCA\DAV\Tests\DAV;
 
 use OCA\DAV\DAV\CustomPropertiesBackend;
+use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
 use OCP\IUser;
+use Sabre\CalDAV\ICalendar;
+use Sabre\DAV\Exception\NotFound;
 use Sabre\DAV\PropFind;
 use Sabre\DAV\PropPatch;
+use Sabre\DAV\Server;
 use Sabre\DAV\Tree;
+use Sabre\DAV\Xml\Property\Href;
+use Sabre\DAVACL\IACL;
+use Sabre\DAVACL\IPrincipal;
 use Test\TestCase;
 
 /**
  * @group DB
  */
 class CustomPropertiesBackendTest extends TestCase {
+	private const BASE_URI = '/remote.php/dav/';
+
+	/** @var Server | \PHPUnit\Framework\MockObject\MockObject */
+	private $server;
+
 	/** @var Tree | \PHPUnit\Framework\MockObject\MockObject */
 	private $tree;
 
@@ -54,6 +67,9 @@ class CustomPropertiesBackendTest extends TestCase {
 	protected function setUp(): void {
 		parent::setUp();
 
+		$this->server = $this->createMock(Server::class);
+		$this->server->method('getBaseUri')
+			->willReturn(self::BASE_URI);
 		$this->tree = $this->createMock(Tree::class);
 		$this->user = $this->createMock(IUser::class);
 		$this->user->method('getUID')
@@ -62,9 +78,10 @@ class CustomPropertiesBackendTest extends TestCase {
 		$this->dbConnection = \OC::$server->getDatabaseConnection();
 
 		$this->backend = new CustomPropertiesBackend(
+			$this->server,
 			$this->tree,
 			$this->dbConnection,
-			$this->user
+			$this->user,
 		);
 	}
 
@@ -90,7 +107,13 @@ class CustomPropertiesBackendTest extends TestCase {
 		}
 	}
 
-	protected function insertProp(string $user, string $path, string $name, string $value) {
+	protected function insertProp(string $user, string $path, string $name, mixed $value) {
+		$type = CustomPropertiesBackend::PROPERTY_TYPE_STRING;
+		if ($value instanceof Href) {
+			$value = $value->getHref();
+			$type = CustomPropertiesBackend::PROPERTY_TYPE_HREF;
+		}
+
 		$query = $this->dbConnection->getQueryBuilder();
 		$query->insert('properties')
 			->values([
@@ -98,13 +121,14 @@ class CustomPropertiesBackendTest extends TestCase {
 				'propertypath' => $query->createNamedParameter($this->formatPath($path)),
 				'propertyname' => $query->createNamedParameter($name),
 				'propertyvalue' => $query->createNamedParameter($value),
+				'valuetype' => $query->createNamedParameter($type, IQueryBuilder::PARAM_INT)
 			]);
 		$query->execute();
 	}
 
 	protected function getProps(string $user, string $path) {
 		$query = $this->dbConnection->getQueryBuilder();
-		$query->select('propertyname', 'propertyvalue')
+		$query->select('propertyname', 'propertyvalue', 'valuetype')
 			->from('properties')
 			->where($query->expr()->eq('userid', $query->createNamedParameter($user)))
 			->andWhere($query->expr()->eq('propertypath', $query->createNamedParameter($this->formatPath($path))));
@@ -112,7 +136,11 @@ class CustomPropertiesBackendTest extends TestCase {
 		$result = $query->execute();
 		$data = [];
 		while ($row = $result->fetch()) {
-			$data[$row['propertyname']] = $row['propertyvalue'];
+			$value = $row['propertyvalue'];
+			if ((int)$row['valuetype'] === CustomPropertiesBackend::PROPERTY_TYPE_HREF) {
+				$value = new Href($value);
+			}
+			$data[$row['propertyname']] = $value;
 		}
 		$result->closeCursor();
 
@@ -122,9 +150,10 @@ class CustomPropertiesBackendTest extends TestCase {
 	public function testPropFindNoDbCalls(): void {
 		$db = $this->createMock(IDBConnection::class);
 		$backend = new CustomPropertiesBackend(
+			$this->server,
 			$this->tree,
 			$db,
-			$this->user
+			$this->user,
 		);
 
 		$propFind = $this->createMock(PropFind::class);
@@ -186,10 +215,169 @@ class CustomPropertiesBackendTest extends TestCase {
 		$this->assertEquals($props, $setProps);
 	}
 
+	public function testPropFindPrincipalCall(): void {
+		$this->tree->method('getNodeForPath')
+			->willReturnCallback(function ($uri) {
+				$node = $this->createMock(ICalendar::class);
+				$node->method('getOwner')
+					->willReturn('principals/users/dummy_user_42');
+				return $node;
+			});
+
+		$propFind = $this->createMock(PropFind::class);
+		$propFind->method('get404Properties')
+			->with()
+			->willReturn([
+				'{DAV:}getcontentlength',
+				'{DAV:}getcontenttype',
+				'{DAV:}getetag',
+				'{abc}def',
+			]);
+
+		$propFind->method('getRequestedProperties')
+			->with()
+			->willReturn([
+				'{DAV:}getcontentlength',
+				'{DAV:}getcontenttype',
+				'{DAV:}getetag',
+				'{abc}def',
+				'{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL',
+			]);
+
+		$props = [
+			'{abc}def' => 'a',
+			'{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('calendars/admin/personal'),
+		];
+		$this->insertProps('dummy_user_42', 'principals/users/dummy_user_42', $props);
+
+		$setProps = [];
+		$propFind->method('set')
+			->willReturnCallback(function ($name, $value, $status) use (&$setProps): void {
+				$setProps[$name] = $value;
+			});
+
+		$this->backend->propFind('principals/users/dummy_user_42', $propFind);
+		$this->assertEquals($props, $setProps);
+	}
+
+	public function propFindPrincipalScheduleDefaultCalendarProviderUrlProvider(): array {
+		// [ user, nodes, existingProps, requestedProps, returnedProps ]
+		return [
+			[ // Exists
+				'dummy_user_42',
+				['calendars/dummy_user_42/foo/' => ICalendar::class],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('calendars/dummy_user_42/foo/')],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL'],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('calendars/dummy_user_42/foo/')],
+			],
+			[ // Doesn't exist
+				'dummy_user_42',
+				['calendars/dummy_user_42/foo/' => ICalendar::class],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('calendars/dummy_user_42/bar/')],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL'],
+				[],
+			],
+			[ // No privilege
+				'dummy_user_42',
+				['calendars/user2/baz/' => ICalendar::class],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('calendars/user2/baz/')],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL'],
+				[],
+			],
+			[ // Not a calendar
+				'dummy_user_42',
+				['foo/dummy_user_42/bar/' => IACL::class],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('foo/dummy_user_42/bar/')],
+				['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL'],
+				[],
+			],
+		];
+
+	}
+
+	/**
+	 * @dataProvider propFindPrincipalScheduleDefaultCalendarProviderUrlProvider
+	 */
+	public function testPropFindPrincipalScheduleDefaultCalendarUrl(
+		string $user,
+		array $nodes,
+		array $existingProps,
+		array $requestedProps,
+		array $returnedProps,
+	): void {
+		$propFind = $this->createMock(PropFind::class);
+		$propFind->method('get404Properties')
+			->with()
+			->willReturn([
+				'{DAV:}getcontentlength',
+				'{DAV:}getcontenttype',
+				'{DAV:}getetag',
+			]);
+
+		$propFind->method('getRequestedProperties')
+			->with()
+			->willReturn(array_merge([
+				'{DAV:}getcontentlength',
+				'{DAV:}getcontenttype',
+				'{DAV:}getetag',
+				'{abc}def',
+			],
+				$requestedProps,
+			));
+
+		$this->server->method('calculateUri')
+			->willReturnCallback(function ($uri) {
+				if (!str_starts_with($uri, self::BASE_URI)) {
+					return trim(substr($uri, strlen(self::BASE_URI)), '/');
+				}
+				return null;
+			});
+		$this->tree->method('getNodeForPath')
+			->willReturnCallback(function ($uri) use ($nodes) {
+				if (str_starts_with($uri, 'principals/')) {
+					return $this->createMock(IPrincipal::class);
+				}
+				if (array_key_exists($uri, $nodes)) {
+					$owner = explode('/', $uri)[1];
+					$node = $this->createMock($nodes[$uri]);
+					$node->method('getOwner')
+						->willReturn("principals/users/$owner");
+					return $node;
+				}
+				throw new NotFound('Node not found');
+			});
+
+		$this->insertProps($user, "principals/users/$user", $existingProps);
+
+		$setProps = [];
+		$propFind->method('set')
+			->willReturnCallback(function ($name, $value, $status) use (&$setProps): void {
+				$setProps[$name] = $value;
+			});
+
+		$this->backend->propFind("principals/users/$user", $propFind);
+		$this->assertEquals($returnedProps, $setProps);
+	}
+
 	/**
 	 * @dataProvider propPatchProvider
 	 */
 	public function testPropPatch(string $path, array $existing, array $props, array $result): void {
+		$this->server->method('calculateUri')
+			->willReturnCallback(function ($uri) {
+				if (str_starts_with($uri, self::BASE_URI)) {
+					return trim(substr($uri, strlen(self::BASE_URI)), '/');
+				}
+				return null;
+			});
+		$this->tree->method('getNodeForPath')
+			->willReturnCallback(function ($uri) {
+				$node = $this->createMock(ICalendar::class);
+				$node->method('getOwner')
+					->willReturn('principals/users/' . $this->user->getUID());
+				return $node;
+			});
+
 		$this->insertProps($this->user->getUID(), $path, $existing);
 		$propPatch = new PropPatch($props);
 
@@ -207,6 +395,8 @@ class CustomPropertiesBackendTest extends TestCase {
 			['foo_bar_path_1337', ['{DAV:}displayname' => 'foo'], ['{DAV:}displayname' => 'anything'], ['{DAV:}displayname' => 'anything']],
 			['foo_bar_path_1337', ['{DAV:}displayname' => 'foo'], ['{DAV:}displayname' => null], []],
 			[$longPath, [], ['{DAV:}displayname' => 'anything'], ['{DAV:}displayname' => 'anything']],
+			['principals/users/dummy_user_42', [], ['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('foo/bar/')], ['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('foo/bar/')]],
+			['principals/users/dummy_user_42', [], ['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href(self::BASE_URI . 'foo/bar/')], ['{urn:ietf:params:xml:ns:caldav}schedule-default-calendar-URL' => new Href('foo/bar/')]],
 		];
 	}