fts_safe_changedir
if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) {
static int fts_safe_changedir(FTS *, FTSENT *, int, char *);
fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {