[gssdp: 1/2] Fix support for IPV6_PKTINFO on macOS

[Jens Georg <jensgeorg src gnome org>]

commit 8b333104cfaed32fb657b3354b36ac3b51342b38
Author: Tom Schoonjans <Tom Schoonjans diamond ac uk>
Date:   Fri Nov 16 12:39:28 2018 +0000

    Fix support for IPV6_PKTINFO on macOS
    
    Apparently IPV6_PKTINFO is not defined on macOS, unless
    __APPLE_USE_RFC_3542 is defined before including <netinet.h>.

 libgssdp/gssdp-pktinfo6-message.c | 4 ++++
 libgssdp/gssdp-socket-functions.c | 4 ++++
 2 files changed, 8 insertions(+)
---
diff --git a/libgssdp/gssdp-pktinfo6-message.c b/libgssdp/gssdp-pktinfo6-message.c
index 4f373b4..320240b 100644
--- a/libgssdp/gssdp-pktinfo6-message.c
+++ b/libgssdp/gssdp-pktinfo6-message.c
@@ -21,6 +21,10 @@
 
 #define _GNU_SOURCE
 
+#ifdef __APPLE__
+#define __APPLE_USE_RFC_3542
+#endif
+
 #include <sys/socket.h>
 #include <netinet/ip.h>
 
diff --git a/libgssdp/gssdp-socket-functions.c b/libgssdp/gssdp-socket-functions.c
index 457cd66..48cce65 100644
--- a/libgssdp/gssdp-socket-functions.c
+++ b/libgssdp/gssdp-socket-functions.c
@@ -23,6 +23,10 @@
 #include <config.h>
 #endif /* HAVE_CONFIG_H */
 
+#ifdef __APPLE__
+#define __APPLE_USE_RFC_3542
+#endif
+
 #include "gssdp-error.h"
 #include "gssdp-socket-functions.h"
 #include "gssdp-pktinfo-message.h"