rem: int n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t); size_t *length = (size_t *) obstack_base (&ds->len_stack);
add: size_t n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t); size_t *length = obstack_base (&ds->len_stack);
context: top_dir (Dirstack_state const *ds){  int n_lengths = obstack_object_size (&ds->len_stack) / sizeof (size_t);  size_t *length = (size_t *) obstack_base (&ds->len_stack);  size_t top_len = length[n_lengths - 1];  char const *p = obstack_next_free (&ds->dir_stack) - top_len;  char *q = xmalloc (top_len);  memcpy (q, p, top_len - 1);  q[top_len - 1] = 0;  return q;}