From 49be64e571cdc0ca1562cdd104a7943e1b57ffe4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Fri, 4 Mar 2016 14:07:19 +0200
Subject: udpsrc: Fix multicast group joining with provided sockets on Windows

On Windows the socket will be bound to ANY instead of the multicast group,
as binding to a multicast group does not work. Which would mean that we
override src->addr to become ANY and won't automatically join a multicast
group anymore on Windows.

On Linux we would automatically join a multicast group, keep it consistent.

https://bugzilla.gnome.org/show_bug.cgi?id=763093
---
 gst/udp/gstudpsrc.c | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/gst/udp/gstudpsrc.c b/gst/udp/gstudpsrc.c
index 34aa7e464..1525b0505 100644
--- a/gst/udp/gstudpsrc.c
+++ b/gst/udp/gstudpsrc.c
@@ -968,18 +968,47 @@ gst_udpsrc_open (GstUDPSrc * src)
     g_object_unref (bind_saddr);
     g_socket_set_multicast_loopback (src->used_socket, src->loop);
   } else {
+    GInetSocketAddress *local_addr;
+
     GST_DEBUG_OBJECT (src, "using provided socket %p", src->socket);
     /* we use the configured socket, try to get some info about it */
     src->used_socket = G_SOCKET (g_object_ref (src->socket));
     src->external_socket = TRUE;
 
-    if (src->addr)
-      g_object_unref (src->addr);
-    src->addr =
+    local_addr =
         G_INET_SOCKET_ADDRESS (g_socket_get_local_address (src->used_socket,
             &err));
-    if (!src->addr)
+    if (!local_addr)
       goto getsockname_error;
+
+    /* See above for the reasons. Without this we would behave different on
+     * Windows and Linux, joining multicast groups below for provided sockets
+     * on Linux but not on Windows
+     */
+#ifdef G_OS_WIN32
+    addr = gst_udpsrc_resolve (src, src->address);
+    if (!addr)
+      goto name_resolve;
+
+    if (!src->auto_multicast ||
+        !g_inet_address_get_is_any (g_inet_socket_address_get_address
+            (local_addr))
+        || !g_inet_address_get_is_multicast (addr)) {
+      g_object_unref (addr);
+#endif
+      if (src->addr)
+        g_object_unref (src->addr);
+      src->addr = local_addr;
+#ifdef G_OS_WIN32
+    } else {
+      g_object_unref (local_addr);
+      if (src->addr)
+        g_object_unref (src->addr);
+      src->addr =
+          G_INET_SOCKET_ADDRESS (g_inet_socket_address_new (addr, src->port));
+      g_object_unref (addr);
+    }
+#endif
   }
 
   {
-- 
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