From ef089f50f9d6685c7a0ab94f9133576d7beec32b Mon Sep 17 00:00:00 2001
From: Yegappan Lakshmanan <yegappan@yahoo.com>
Date: Fri, 31 Dec 2021 17:33:47 +0000
Subject: [PATCH] patch 8.2.3958: build failure compiling xxd with "-std=c2x"

Problem:    Build failure compiling xxd with "-std=c2x".
Solution:   define _XOPEN_SOURCE. (Yegappan Lakshmanan, closes #9444)
---
 src/version.c | 2 ++
 src/xxd/xxd.c | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/src/version.c b/src/version.c
index 043147400..80f504835 100644
--- a/src/version.c
+++ b/src/version.c
@@ -749,6 +749,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3958,
 /**/
     3957,
 /**/
diff --git a/src/xxd/xxd.c b/src/xxd/xxd.c
index cf2a3569f..c32b9b8fb 100644
--- a/src/xxd/xxd.c
+++ b/src/xxd/xxd.c
@@ -72,6 +72,10 @@
 # define CYGWIN
 #endif
 
+#if (defined(__linux__) && !defined(__ANDROID__)) || defined(__CYGWIN__)
+# define _XOPEN_SOURCE 700   /* for fdopen() */
+#endif
+
 #include <stdio.h>
 #ifdef VAXC
 # include <file.h>
-- 
2.50.1