From 445c33fb8883b7c7946ab8cf93015f167c971f44 Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Mon, 14 May 2018 17:43:42 -0700
Subject: [PATCH] Add #define needed for Cygwin

---
 tile-join.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tile-join.cpp b/tile-join.cpp
index b5e59e4..f00031d 100644
--- a/tile-join.cpp
+++ b/tile-join.cpp
@@ -1,3 +1,8 @@
+// for vasprintf() on Linux
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
 #define _DEFAULT_SOURCE
 #include <dirent.h>
 #include <sys/stat.h>