Catch forbidden http status code

If you try to do something on a DAV mount (external or federated share)
that is not allowed. We should not mark the storage as not available but
just fail somewhat gracefully.

Now by catching this and just properly returning the operation will just
fail (and notify the user) which is already a lot better then marking
the storage as unavailable and doing boom.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

lib/private/Files/Storage/DAV.php

@@ -35,6 +35,7 @@ namespace OC\Files\Storage;
 
 use Exception;
 use GuzzleHttp\Exception\RequestException;
+use OCP\Files\ForbiddenException;
 use OCP\ILogger;
 use Psr\Http\Message\ResponseInterface;
 use Icewind\Streams\CallbackWrapper;
@@ -829,6 +830,7 @@ class DAV extends Common {
 	 * when the authentication expired or is invalid
 	 * @throws StorageNotAvailableException if the storage is not available,
 	 * which might be temporary
+	 * @throws ForbiddenException if the action is not allowed
 	 */
 	protected function convertException(Exception $e, $path = '') {
 		\OC::$server->getLogger()->logException($e, ['app' => 'files_external', 'level' => ILogger::DEBUG]);
@@ -842,6 +844,9 @@ class DAV extends Common {
 			} else if ($e->getHttpStatus() === Http::STATUS_METHOD_NOT_ALLOWED) {
 				// ignore exception for MethodNotAllowed, false will be returned
 				return;
+			} else if ($e->getHttpStatus() === Http::STATUS_FORBIDDEN){
+				// The operation is forbidden. Fail somewhat gracefully
+				throw new ForbiddenException(get_class($e) . ':' . $e->getMessage());
 			}
 			throw new StorageNotAvailableException(get_class($e) . ': ' . $e->getMessage());
 		} else if ($e instanceof ClientException) {