_casbaseddirectory: Fix order of list_modified_paths

        else:

            self._mark_directory_unmodified()

    def _lightweight_resolve_to_index(self, path):

        """A lightweight function for transforming paths into IndexEntry

        objects. This does not follow symlinks.

        path: The string to resolve. This should be a series of path

        components separated by the protocol buffer path separator

        _pb2_path_sep.

        Returns: the IndexEntry found, or None if any of the path components were not present.

        """

        directory = self

        path_components = path.split(CasBasedDirectory._pb2_path_sep)

        for component in path_components[:-1]:

            if component not in directory.index:

                return None

            if isinstance(directory.index[component].buildstream_object, CasBasedDirectory):

                directory = directory.index[component].buildstream_object

            else:

                return None

        return directory.index.get(path_components[-1], None)

    def list_modified_paths(self):

        """Provide a list of relative paths which have been modified since the

        last call to mark_unmodified.

        Return value: List(str) - list of modified paths

        """

        filelist = []

        for (k, v) in self.index.items():

            if isinstance(v.buildstream_object, CasBasedDirectory):

                filelist.extend([k + os.path.sep + x for x in v.buildstream_object.list_modified_paths()])

            elif isinstance(v.pb_object, remote_execution_pb2.FileNode) and v.modified:

                filelist.append(k)

        return filelist

        for p in self.list_relative_paths():

            i = self._lightweight_resolve_to_index(p)

            if i and i.modified:

                yield p

    def list_relative_paths(self, relpath=""):

        """Provide a list of all relative paths.

        NOTE: This list is not in the same order as utils.list_relative_paths.

        Return value: List(str) - list of all paths

        """