owncloud / core

				\OCP\Util::writeLog('OCP\Share', \sprintf($message, $itemSourceName), \OCP\Util::DEBUG);

				throw new \Exception($message_t);

			}

			if (!\OC_User::userExists($shareWith)) {

				$message = 'Sharing %s failed, because the user %s does not exist';

				$message_t = $l->t('Sharing %s failed, because the user %s does not exist', [$itemSourceName, $shareWith]);

				\OCP\Util::writeLog('OCP\Share', \sprintf($message, $itemSourceName, $shareWith), \OCP\Util::DEBUG);

				throw new \Exception($message_t);

			}

			if ($shareWithinGroupOnly) {

				$inGroup = \array_intersect(self::getGroupsForUser($uidOwner), self::getGroupsForUser($shareWith));

				if (empty($inGroup)) {

			list($user, $remote) = Helper::splitUserRemote($shareWith);

			$currentServer = self::removeProtocolFromUrl(\OC::$server->getURLGenerator()->getAbsoluteURL('/'));

			$currentUser = \OC::$server->getUserSession()->getUser()->getUID();

			if (Helper::isSameUserOnSameServer($user, $remote, $currentUser, $currentServer)) {

				$message = 'Not allowed to create a federated share with the same user.';

				$message_t = $l->t('Not allowed to create a federated share with the same user');

				\OCP\Util::writeLog('OCP\Share', $message, \OCP\Util::DEBUG);

				throw new \Exception($message_t);

			}

			$token = \OC::$server->getSecureRandom()->generate(self::TOKEN_LENGTH, \OCP\Security\ISecureRandom::CHAR_LOWER . \OCP\Security\ISecureRandom::CHAR_UPPER .

				\OCP\Security\ISecureRandom::CHAR_DIGITS);

			$class = self::$backendTypes[$itemType]['class'];

			if (\class_exists($class)) {

				self::$backends[$itemType] = new $class;

				if (!(self::$backends[$itemType] instanceof \OCP\Share_Backend)) {

					$message = 'Sharing backend %s must implement the interface OCP\Share_Backend';

					$message_t = $l->t('Sharing backend %s must implement the interface OCP\Share_Backend', [$class]);

					\OCP\Util::writeLog('OCP\Share', \sprintf($message, $class), \OCP\Util::ERROR);

					throw new \Exception($message_t);

				}

				return self::$backends[$itemType];

			} else {

				$message = 'Sharing backend %s not found';