From e2cef70fec5fc03ca28987f8005b6549e9e23e6b Mon Sep 17 00:00:00 2001
From: David Levine <levinedl@acm.org>
Date: Tue, 25 Oct 2016 11:05:54 -0400
Subject: [PATCH] Don't add -D_FORTIFY_SOURCE to AM_CPPFLAGS with -O0.

---
 configure.ac | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 02a39243..94558d4c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -165,8 +165,10 @@ if test "$GCC" = yes; then
   dnl If the user configures with a CFLAGS that contains a -O flag
   dnl but then removes it a make time, they'll also have to remove
   dnl -D_FORTIFY_SOURCE from AM_CPPFLAGS because it requires optimization.
+  dnl Use "\ " instead of ' ' or " " for compatiblity with posh.
   AS_CASE([$CFLAGS],
-          [-O*|*' -O'*],[AM_CPPFLAGS="${AM_CPPFLAGS:+$AM_CPPFLAGS }-D_FORTIFY_SOURCE=2"])
+          [-O|*\ -O|-O[[!0]]*|*\ -O[[!0]]*],
+          [AM_CPPFLAGS="${AM_CPPFLAGS:+$AM_CPPFLAGS }-D_FORTIFY_SOURCE=2"])
 fi
 
 dnl FreeBSD needs a bit of magic to bring getline() into scope.
-- 
2.56.0