Strange hostname completions after unset HOSTFILE

[Freddy Vulto]

Configuration Information:
Machine: i486
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i486'
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i486-pc-linux-gnu'
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash'
-DSHELL -DHAVE_CONFIG_H   -I.  -I../bash -I../bash/include
-I../bash/lib   -g -O2 -Wall
uname output: Linux rebase 2.6.28-14-generic #47-Ubuntu SMP Sat Jul
25 00:28:35 UTC 2009 i686 GNU/Linux
Machine Type: i486-pc-linux-gnu

Bash Version: 3.2
Patch Level: 48
Release Status: release

Description:
    The manual says that upon unsetting HOSTFILE, the hostname list is cleared:

        HOSTFILE
        Contains the name of a file in the  same  format  as /etc/hosts
        that should be read when the shell needs to complete a hostname.
        The list of possible hostname completions may be  changed  while
        the  shell  is running;  the  next  time hostname completion is
        attempted after the value is changed, bash adds the contents  of
        the new file to the existing list.  If HOSTFILE is set, but has
        no value, bash attempts to read /etc/hosts to obtain the list of
        possible  hostname  completions.   When HOSTFILE  is unset, the
        hostname list is cleared.

    but when I do so, instead of returning nothing, `compgen -A
    hostname' returns strange data.

Repeat-By:
    $ echo -n $HOSTFILE
    $ cat -v /etc/hosts
    127.0.0.1   localhost
    127.0.1.1   freddy
    $ compgen -A hostname
    localhost
    freddy
    $ unset -v HOSTFILE
    $ compgen -A hostname
    ���������

    ���������
    $

I tested on another machine with bash-3.1 (patch level 17), having the
same problem.

Regards, Freddy Vulto
http://fvue.nl