From 5f4ca3541f228b0b9b880406e70342dea5a2a7a9 Mon Sep 17 00:00:00 2001
From: Jeremy Harris <jgh146exb@wizmail.org>
Date: Sat, 26 Dec 2020 18:55:29 +0000
Subject: [PATCH] Fix build on GNU/Hurd [supports openat()].  Bug 2608

---
 src/OS/os.h-GNU | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/OS/os.h-GNU b/src/OS/os.h-GNU
index 59130ef10..2c3b7b5f5 100644
--- a/src/OS/os.h-GNU
+++ b/src/OS/os.h-GNU
@@ -1,6 +1,8 @@
 /* Exim: OS-specific C header file for GNU/Hurd */
 /* Copyright (c) The Exim Maintainers 2020 */
 
+#include <features.h>
+
 #define CRYPT_H
 #define GLIBC_IP_OPTIONS
 #define HAVE_BSD_GETLOADAVG
@@ -25,4 +27,8 @@ typedef struct flock flock_t;
 as well as any supplementary groups*/
 #define OS_SETGROUPS_ZERO_DROPS_ALL
 
+#if _POSIX_C_SOURCE >= 200809L || _ATFILE_SOURCE
+# define EXIM_HAVE_OPENAT
+#endif
+
 /* End */
-- 
2.30.2