diff -urp coreutils-6.10-orig/lib/getugroups.c coreutils-6.10/lib/getugroups.c

--- coreutils-6.10-orig/lib/getugroups.c	2007-10-17 15:47:25.000000000 +0200

+++ coreutils-6.10/lib/getugroups.c	2008-01-24 16:37:04.000000000 +0100

@@ -19,6 +19,9 @@

 #include <config.h>

+/* We do not need this code if getgrouplist(3) is available.  */

+#ifndef HAVE_GETGROUPLIST

+

 #include "getugroups.h"

 #include <stdio.h> /* grp.h on alpha OSF1 V2.0 uses "FILE *". */

@@ -114,3 +117,4 @@ getugroups (int maxcount, GETGROUPS_T *g

   return count;

 }

+#endif	/* have getgrouplist */

diff -urp coreutils-6.10-orig/lib/mgetgroups.c coreutils-6.10/lib/mgetgroups.c

--- coreutils-6.10-orig/lib/mgetgroups.c	2007-11-25 14:23:31.000000000 +0100

+++ coreutils-6.10/lib/mgetgroups.c	2008-01-24 16:41:15.000000000 +0100

@@ -43,9 +43,17 @@ mgetgroups (const char *username, gid_t 

   int ng;

   GETGROUPS_T *g;

-  max_n_groups = (username

-		  ? getugroups (0, NULL, username, gid)

-		  : getgroups (0, NULL));

+    if (!username)

+      max_n_groups = getgroups(0, NULL);

+  else 

+   {

+#ifdef HAVE_GETGROUPLIST

+      max_n_groups = 0;

+      getgrouplist (username, gid, NULL, &max_n_groups);

+#else

+      max_n_groups = getugroups (0, NULL, username, gid);

+#endif

+   }

   /* If we failed to count groups with NULL for a buffer,

      try again with a non-NULL one, just in case.  */

@@ -62,9 +70,25 @@ mgetgroups (const char *username, gid_t 

   if (g == NULL)

     return -1;

-  ng = (username

-	? getugroups (max_n_groups, g, username, gid)

-	: getgroups (max_n_groups, g));

+  if (!username)

+    ng = getgroups (max_n_groups, g);

+  else

+    {

+#ifdef HAVE_GETGROUPLIST

+	  int e;

+	  ng = max_n_groups;

+	  while ((e = getgrouplist (username, gid, g, &ng)) == -1

+		 && ng > max_n_groups)

+	    {

+	      max_n_groups = ng;

+	      g = xrealloc (g, max_n_groups * sizeof (GETGROUPS_T));

+	    }

+	  if (e == -1)

+	    ng = -1;

+#else

+	  ng = getugroups (max_n_groups, g, username, gid);

+#endif

+    }

   if (ng < 0)

     {

diff -urp coreutils-6.10-orig/m4/jm-macros.m4 coreutils-6.10/m4/jm-macros.m4

--- coreutils-6.10-orig/m4/jm-macros.m4	2007-11-25 14:23:31.000000000 +0100

+++ coreutils-6.10/m4/jm-macros.m4	2008-01-24 16:42:00.000000000 +0100

@@ -52,6 +52,7 @@ AC_DEFUN([coreutils_MACROS],

     fchown \

     fchmod \

     ftruncate \

+    getgrouplist \

     iswspace \

     mkfifo \

     mbrlen \