Replace groups.sh with groups.c.

* src/groups.c (main): New file, replacing groups.sh.
* src/group-list.c, src/group-list.h: New files, factored out of id.c,
implementing the functionality that "id" and "groups" have in common.
* src/id.c (print_full_info): Avoid a segfault when trying to print
an error message if getgroups fails.
(print_group_list): Move to group-list.c.
(print_group): Likewise.
* man/Makefile.am: When building groups.1, obtain the help text
from src/groups.c, not src/groups.sh.
(noinst_HEADERS): Add group-list.h.
(group): Remove rule.
(dist_man_MANS): Remove groups.1.
* doc/coreutils.texi (groups: Print group names a user is in):
Explain why "groups" and "groups $(id -un)" give different results
in existing login sessions after you change the group database.
(id: Print user identity): Likewise for "id".
* po/POTFILES.in: Add src/group-list.c and src/groups.c.
* NEWS: mention this.
* AUTHORS: Update.

1 files changed, 3 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index e05e1c318..af27aab1d 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,9 @@ GNU coreutils NEWS                                    -*- outline -*-
 
 ** Bug fixes
 
+  configure --enable-no-install-program=groups now works.
+
+
   ls no longer segfaults on files in /proc when linked with an older version
   of libselinux.  E.g., ls -l /proc/sys would dereference a NULL pointer.