--- coreutils-5.2.1/m4/jm-macros.m4.getgrouplist	2003-12-20 17:57:18.000000000 +0000
+++ coreutils-5.2.1/m4/jm-macros.m4	2004-10-05 12:43:14.975401711 +0100
@@ -83,6 +83,7 @@
     endpwent \
     fdatasync \
     ftruncate \
+    getgrouplist \
     gethrtime \
     hasmntopt \
     isascii \
--- coreutils-5.2.1/lib/getugroups.c.getgrouplist	2003-09-10 07:23:09.000000000 +0100
+++ coreutils-5.2.1/lib/getugroups.c	2004-10-05 12:43:14.980400761 +0100
@@ -21,6 +21,9 @@
 # include <config.h>
 #endif
 
+/* We do not need this code if getgrouplist(3) is available.  */
+#ifndef HAVE_GETGROUPLIST
+
 #include <sys/types.h>
 #include <stdio.h> /* grp.h on alpha OSF1 V2.0 uses "FILE *". */
 #include <grp.h>
@@ -95,3 +98,4 @@
 
   return count;
 }
+#endif	/* have getgrouplist */
--- coreutils-5.2.1/src/id.c.getgrouplist	2004-10-05 12:26:40.222539037 +0100
+++ coreutils-5.2.1/src/id.c	2004-10-05 12:43:14.986399620 +0100
@@ -316,14 +316,36 @@
   if (username == 0)
     max_n_groups = getgroups (0, NULL);
   else
-    max_n_groups = getugroups (0, NULL, username, gid);
+    {
+#ifdef HAVE_GETGROUPLIST
+      max_n_groups = 0;
+      getgrouplist (username, gid, NULL, &max_n_groups);
+#else
+      max_n_groups = getugroups (0, NULL, username, gid);
+#endif
+    }
 
   /* Add 1 just in case max_n_groups is zero.  */
   g = xmalloc (max_n_groups * sizeof (GETGROUPS_T) + 1);
   if (username == 0)
     ng = getgroups (max_n_groups, g);
   else
-    ng = getugroups (max_n_groups, g, username, gid);
+    {
+#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)
     {