From 9af44b1829ad46f0550325cf871f76d7b40b1ca8 Mon Sep 17 00:00:00 2001
From: Rob Browning <rlb@defaultvalue.org>
Date: Sun, 21 Jun 2020 12:09:16 -0500
Subject: [PATCH] Don't assume readline always defines _XOPEN_SOURCE

Signed-off-by: Rob Browning <rlb@defaultvalue.org>
---
 lib/bup/_helpers.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/bup/_helpers.c b/lib/bup/_helpers.c
index 67c39b5..13f72c6 100644
--- a/lib/bup/_helpers.c
+++ b/lib/bup/_helpers.c
@@ -46,10 +46,12 @@
 #include <time.h>
 #endif
 
-#ifdef BUP_HAVE_READLINE
-#if ! defined(_XOPEN_SOURCE) || _XOPEN_SOURCE < BUP_RL_EXPECTED_XOPEN_SOURCE
-# warning "_XOPEN_SOURCE version is too low for readline"
+#if defined(BUP_RL_EXPECTED_XOPEN_SOURCE) \
+    && (!defined(_XOPEN_SOURCE) || _XOPEN_SOURCE < BUP_RL_EXPECTED_XOPEN_SOURCE)
+# warning "_XOPEN_SOURCE version is incorrect for readline"
 #endif
+
+#ifdef BUP_HAVE_READLINE
 #include <readline/readline.h>
 #include <readline/history.h>
 #endif
-- 
2.39.2