Allow passing a root folder to get the used space from in the quota wrapper

lib/private/files/storage/wrapper/quota.php

@@ -15,12 +15,18 @@ class Quota extends Wrapper {
 	 */
 	protected $quota;
 
+	/**
+	 * @var string $freeSpaceRoot
+	 */
+	protected $sizeRoot;
+
 	/**
 	 * @param array $parameters
 	 */
 	public function __construct($parameters) {
 		$this->storage = $parameters['storage'];
 		$this->quota = $parameters['quota'];
+		$this->freeSpaceRoot = isset($parameters['root']) ? $parameters['root'] : '';
 	}
 
 	protected function getSize($path) {
@@ -43,7 +49,7 @@ class Quota extends Wrapper {
 		if ($this->quota < 0) {
 			return $this->storage->free_space($path);
 		} else {
-			$used = $this->getSize('');
+			$used = $this->getSize($this->freeSpaceRoot);
 			if ($used < 0) {
 				return \OC\Files\SPACE_NOT_COMPUTED;
 			} else {

lib/private/util.php

@@ -65,7 +65,7 @@ class OC_Util {
 					$user = $storage->getUser()->getUID();
 					$quota = OC_Util::getUserQuota($user);
 					if ($quota !== \OC\Files\SPACE_UNLIMITED) {
-						return new \OC\Files\Storage\Wrapper\Quota(array('storage' => $storage, 'quota' => $quota));
+						return new \OC\Files\Storage\Wrapper\Quota(array('storage' => $storage, 'quota' => $quota, 'root' => 'files'));
 					}
 				}