SCM_ALLOW_INTS in scm_make_weak_*_hash_table

[Keisuke Nishida]

Hello,

I don't understand why SCM_ALLOW_INTS is called twice in the functions
scm_make_weak_key_hash_table, scm_make_weak_value_hash_table, and
scm_make_doubly_weak_hash_table.  Isn't this a bug?

SCM_DEFINE (scm_make_weak_key_hash_table, "make-weak-key-hash-table", 1, 0, 0, 
           (SCM k),
{
  SCM v;
  SCM_VALIDATE_INUM (1,k);
  v = scm_make_weak_vector (k, SCM_EOL);
  SCM_ALLOW_INTS;
  SCM_UNPACK (SCM_VELTS (v)[-1]) = 1;
  SCM_ALLOW_INTS;
  return v;
}