From a0e53000a8d2f464c5a49e93abaa606e67d7558e Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@openssl.org>
Date: Fri, 29 Jun 2018 18:46:57 +0200
Subject: [PATCH] rand/rand_unix.c: address macro redifinition warning.

Occasionally, e.g. when compiling for elderly glibc, you end up passing
-D_GNU_SOURCE on command line, and doing so triggered warning...

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6616)
---
 crypto/rand/rand_unix.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/crypto/rand/rand_unix.c b/crypto/rand/rand_unix.c
index b64cf27825..f482de063a 100644
--- a/crypto/rand/rand_unix.c
+++ b/crypto/rand/rand_unix.c
@@ -7,7 +7,9 @@
  * https://www.openssl.org/source/license.html
  */
 
-#define _GNU_SOURCE
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
 #include "e_os.h"
 #include <stdio.h>
 #include "internal/cryptlib.h"
-- 
2.25.1