/* after loading all level set information, clone the level directory tree
and remove all level sets without levels (these may still contain artwork
to be offered in the setup menu as "custom artwork", and are therefore
checked for existing artwork in the function "LoadLevelArtworkInfo()") */
leveldir_first_all = leveldir_first;
cloneTree(&leveldir_first, leveldir_first_all, TRUE);
/* after loading all level set information, clone the level directory tree
and remove all level sets without levels (these may still contain artwork
to be offered in the setup menu as "custom artwork", and are therefore
checked for existing artwork in the function "LoadLevelArtworkInfo()") */
leveldir_first_all = leveldir_first;
cloneTree(&leveldir_first, leveldir_first_all, TRUE);