SIO_INPUT stream allows write

[kamahen]

The following code didn't produce an exception. I need to do some additional work to make sure it isn't a bug in my test cases - the test case creates the stream term using with_output_to(string(String), ...), so the problem could be there. [Opening an "issue" because I don't want to forget this - please assign it to me if the problem isn't obvious]

static foreign_t
w_atom_ffi_(term_t stream, term_t t)
{ IOSTREAM* s;
  atom_t a;
  if ( !PL_get_stream(stream, &s, SIO_INPUT || /* should be SIO_OUTPUT */
       !PL_get_atom_ex(t, &a) )
    return FALSE;
  PL_STRINGS_MARK();
    size_t len;
    const pl_wchar_t *sa = PL_atom_wchars(a, &len);
    SfprintfX(s, "/%Ws/%zd", sa, len); /* should fail */
  PL_STRINGS_RELEASE();
  return TRUE;
}

For the test, this is wrapped with:

w_atom_ffi(Atom, String) :-
    with_output_to(string(String), w_atom_ffi_(current_output, Atom)).

[JanWielemaker]

I think it should indeed produce an exception. Run under gdb, break on PL_raise_exception() and see how it goes on ....