From cd4f3c7ad82ef11e73a8c5a53cea2fb812b7dd60 Mon Sep 17 00:00:00 2001
From: Henning Westerholt <hw@skalatan.de>
Date: Tue, 1 Oct 2019 18:00:13 +0200
Subject: [PATCH] core: fix compile error related to missing T_OPT in older
 (<2.25) glibc (GH #2087)

(cherry picked from commit 325d1e6d53b3db3265d6f76ec34bb3d6a31419c4)
---
 src/core/resolve.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/core/resolve.c b/src/core/resolve.c
index fd74441bf6d..9f9705341e7 100644
--- a/src/core/resolve.c
+++ b/src/core/resolve.c
@@ -32,6 +32,13 @@
 #include <resolv.h>
 #include <string.h>
 
+/* older glibc < 2.25 does not include T_OPT in nameser_compat.h yet */
+#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 25
+#ifndef T_OPT
+#define T_OPT ns_t_opt
+#endif
+#endif
+
 #include "resolve.h"
 #include "compiler_opt.h"
 #include "dprint.h"