Bug#637427: libc: nsswitch doesn't respect nsswitch.conf when looking up a single group

[Cheer Xiao <xiaqqaix@gmail.com>]

Package: libc6
Version: 2.11.2-10
Severity: important
File: libc

I have the following line in /etc/nsswitch.conf:

 group: ldap compat

LDAP source is provided by libnss-ldapd (aka nslcd). Now suppose I have
group foo in both the remote LDAP DB and local /etc/group, with
different values:

 (LDAP) foo:*:1500:user1
 (/etc/group) foo:x:500:user2

Invoking

 getent group

will list the LDAP one before the local one, which is expected. However,

 getent group foo

will always show the local one, ie. foo:x:500:user2 instead of the
expected LDAP one. I tried running nslcd in debug mode with

 service nslcd stop && nslcd -d

And it's clear that when I call `getent group foo`, nslcd is *not*
queried. Thus I highly suspect this be a bug in glibc.

-- System Information:
Debian Release: 6.0.2
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 2.6.32-5-686 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libc6 depends on:
ii  libc-bin                      2.11.2-10  Embedded GNU C Library: Binaries
ii  libgcc1                       1:4.4.5-8  GCC support library

Versions of packages libc6 recommends:
ii  libc6-i686                    2.11.2-10  Embedded GNU C Library: Shared lib

Versions of packages libc6 suggests:
ii  debconf [debconf-2.0]         1.5.36.1   Debian configuration management sy
pn  glibc-doc                     <none>     (no description available)
ii  locales                       2.11.2-10  Embedded GNU C Library: National L

-- debconf information:
  glibc/upgrade: true
  glibc/restart-services:
  glibc/disable-screensaver:
  glibc/restart-failed: