tell listing failure in GNU prolog - PROLOG

I try to save databease in GNU prolog , but it failed.
My steps were the followings:
--------------------------------------------------------------------------
GNU Prolog 1.2.16
By Daniel Diaz
Copyright (C) 1999-2002 Daniel Diaz
| ?- assertz(db_test(test)).

yes
| ?- tell('c:\\test.txt').

yes
| ?- listing.

db_test(test).

yes
| ?- told.

yes
| ?-
-------------------------------------------------------------------------------
And when the file 'c:\\test.txt' was checked ,
it was an empty file .

I did the same thing to SWI prolog as the following :
++++++++++++++++++++++++++++++++++++++++
Welcome to SWI-Prolog (Multi-threaded, Version 5.6.12)
Copyright (c) 1990-2006 University of Amsterdam.
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to redistribute it under certain conditions.
Please visit http://www.swi-prolog.org for details.

For help, use ?- help(Topic). or ?- apropos(Word).

1 ?- assertz(db_test(test)).

Yes
2 ?- tell('c:\\test.txt').

Yes
3 ?- listing.

Yes
4 ?- told.

Yes
++++++++++++++++++++++++++++++++++++++++++++++
and the contents of the file 'c:\\test.txt' were
==================================
:- dynamic db_test/1.

db_test(test).
===================================

It is now obvious that GNU prolog gets a bug .