--- sudo-1.6.9p4/configure.in.getgrouplist	2007-08-20 11:41:32.000000000 +0200
+++ sudo-1.6.9p4/configure.in	2007-08-20 13:24:30.000000000 +0200
@@ -1677,7 +1677,7 @@
 dnl
 AC_CHECK_FUNCS(strchr strrchr memchr memcpy memset sysconf tzset \
 	       strftime setrlimit initgroups getgroups fstat gettimeofday \
-	       setlocale getaddrinfo)
+	       setlocale getaddrinfo getgrouplist)
 if test -z "$SKIP_SETRESUID"; then
     AC_CHECK_FUNCS(setresuid, [SKIP_SETREUID=yes])
 fi
--- sudo-1.6.9p4/check.c.getgrouplist	2007-07-06 21:52:13.000000000 +0200
+++ sudo-1.6.9p4/check.c	2007-08-20 13:21:10.000000000 +0200
@@ -308,6 +308,24 @@
 	    return(TRUE);
     }
 
+#ifdef HAVE_GETGROUPLIST
+    {
+	gid_t *grouplist, grouptmp;
+	int n_groups, i;
+	n_groups = 1;
+	if (getgrouplist(user_name, user_gid, &grouptmp, &n_groups) == -1) {
+	    grouplist = (gid_t *) emalloc(sizeof(gid_t) * (n_groups + 1));
+	    if (getgrouplist(user_name, user_gid, grouplist, &n_groups) > 0)
+		for (i = 0; i < n_groups; i++)
+		    if (grouplist[i] == grp->gr_gid) {
+			free(grouplist);
+			return(TRUE);
+		    }
+	    free(grouplist);
+	}
+    }
+#endif
+
     return(FALSE);
 }