From 244fccdddbbee1b9ee43ead4020a0064db0af884 Mon Sep 17 00:00:00 2001
From: Michael Kerrisk <mtk.manpages@gmail.com>
Date: Sat, 8 Oct 2016 11:52:42 +0200
Subject: [PATCH] ffs.3: Correct feature test macro requirements

Reported-by: Stefan Tauner <tauner@technikum-wien.at>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
---
 man3/ffs.3 | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/man3/ffs.3 b/man3/ffs.3
index 11802074c..35da288ae 100644
--- a/man3/ffs.3
+++ b/man3/ffs.3
@@ -57,7 +57,8 @@ Feature Test Macro Requirements for glibc (see
 .RS 4
 .TP 4
 Since glibc 2.12:
-_POSIX_C_SOURCE\ >=\ 200809L
+    _XOPEN_SOURCE >= 700
+    || ! (_POSIX_C_SOURCE\ >=\ 200809L)
     || /* Glibc since 2.19: */ _DEFAULT_SOURCE
     || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
 .TP