Add check for initgroups() since old SYSV lacks this.

config.h.in

@@ -188,6 +188,9 @@
 /* Define if you have innetgr(3).  */
 #undef HAVE_INNETGR
 
+/* Define if you have initgroups(3).  */
+#undef HAVE_INITGROUPS
+
 /* Define if you have getdomainname(2).  */
 #undef HAVE_GETDOMAINNAME
 

configure

@@ -5403,7 +5403,7 @@ EOF
 
 ;;
 esac
-for ac_func in strchr strrchr memchr memcpy memset sysconf sigaction tzset seteuid ftruncate strftime setrlimit
+for ac_func in strchr strrchr memchr memcpy memset sysconf sigaction tzset seteuid ftruncate strftime setrlimit initgroups
 do
 echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
 echo "configure:5410: checking for $ac_func" >&5

configure.in

@@ -1333,7 +1333,7 @@ esac
 dnl
 dnl Function checks
 dnl
-AC_CHECK_FUNCS(strchr strrchr memchr memcpy memset sysconf sigaction tzset seteuid ftruncate strftime setrlimit)
+AC_CHECK_FUNCS(strchr strrchr memchr memcpy memset sysconf sigaction tzset seteuid ftruncate strftime setrlimit initgroups)
 if test -n "$SECUREWARE"; then
     AC_CHECK_FUNCS(bigcrypt)
     AC_CHECK_FUNCS(set_auth_parameters)

sudo.c

@@ -929,7 +929,7 @@ set_perms(perm, sudo_mode)
 					    strerror(errno));
 					exit(1);
 				    }
-
+#ifdef HAVE_INITGROUPS
 				    /*
 				     * Initialize group vector only if are
 				     * going to run as a non-root user.
@@ -942,7 +942,7 @@ set_perms(perm, sudo_mode)
 					    Argv[0], strerror(errno));
 					exit(1);
 				    }
-
+#endif /* HAVE_INITGROUPS */
 				    if (setuid(pw->pw_uid)) {
 					(void) fprintf(stderr,
 					    "%s: cannot set uid to %ld: %s\n",