Here I instead recommend:
     
    bool_vector_type * iactive;
    {
        char * arg_string = stringlist_alloc_joined_string( args );
        iactive = string_util_alloc_active_mask( arg_string );
        free( arg_string );
    }
 
Then you can avoid the slightly problematic  alloc_iactive_list_from_stringlist() function.