Stdio.FILE.ungets has stopped working (?) as well as read/gets pairing

Imported from http://bugzilla.roxen.com/bugzilla/show_bug.cgi?id=1027

Reported by Mirar , Idonex Heavy Industries mirar@roxen.com

From: Robert.Budzynski@fuw.edu.pl (Robert J. Budzynski)
To: pike@roxen.com
Subject: is Stdio.FILE.ungets() broken?
Date: 15 Jan 2001 00:14:26 +0100

rjb@buddy:~/src/Pike/7.1$ pike
Pike v7.1 release 33 running Hilfe v2.0 (Incremental Pike Frontend)
> object f=Stdio.FILE("README");
Result: Stdio.FILE("README", 0, 777 /* fd=10 */)
> string s=f->gets();
Result: "Pike by Fredrik H\374binette 1994-2001"
> f->ungets(s);
Result: 0
> f->gets();
Result: 0
> f->tell();
Result: 1