def prepend_root_dir(opts, path_options):
    '''
    Prepends the options that represent filesystem paths with value of the
    'root_dir' option.
    '''
    root_dir = os.path.abspath(opts['root_dir'])
    root_opt = opts['root_dir'].rstrip(os.sep)
    for path_option in path_options:
        if opts in path_option:
            path = opts[path_option]
            if path == root_opt or path.startswith(root_opt + os.sep):
                path = path[len(root_opt):]
            opts[path_option] = salt.utils.path_join(root_dir, path)
dataset/ETHPy150Open saltstack/salt/salt/config/__init__.py/prepend_root_dir/swapped operands of `in`