From 22e892a22e658ed316133c1e63a17160c735e5e5 Mon Sep 17 00:00:00 2001
From: Denis Kenzior <denkenz@gmail.com>
Date: Fri, 1 Aug 2014 09:29:40 -0500
Subject: [PATCH] build: Avoid warnings about _FORTIFY_SOURCE

Gentoo (and others) define _FORTIFY_SOURCE=2 by default.  We redefine
it, resulting in an error / configure failure.
---
 acinclude.m4 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/acinclude.m4 b/acinclude.m4
index ac29c2bb..13fd52ca 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -12,7 +12,7 @@ AC_DEFUN([AC_PROG_CC_PIE], [
 
 AC_DEFUN([COMPILER_FLAGS], [
 	if (test "${CFLAGS}" = ""); then
-		CFLAGS="-Wall -O2 -D_FORTIFY_SOURCE=2"
+		CFLAGS="-Wall -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2"
 	fi
 	if (test "$USE_MAINTAINER_MODE" = "yes"); then
 		CFLAGS="$CFLAGS -Werror -Wextra"