$NetBSD: patch-config.h.in,v 1.1 2017/10/19 13:51:34 jperkin Exp $

Don't define _XOPEN_SOURCE if using C99.

--- config.h.in.orig	2011-06-14 21:38:39.000000000 +0000
+++ config.h.in
@@ -203,11 +203,13 @@
 /* Use all glibc features. */
 #undef _GNU_SOURCE
 
+#if (__STDC_VERSION__ - 0 < 199901L)
 /* Needed to get declarations for msg_control and msg_controllen on Solaris */
 #undef _XOPEN_SOURCE
 
 /* Needed to get declarations for msg_control and msg_controllen on Solaris */
 #undef _XOPEN_SOURCE_EXTENDED
+#endif
 
 /* Needed to get declarations for msg_control and msg_controllen on Solaris */
 #undef __EXTENSIONS__