[glib] Return correct value for g_socket_get_available_bytes() on Windows and OSX

[Matthias Clasen <matthiasc src gnome org>]

commit 1e598600a16d885a3ca859fe951a5bdd198fd6e7
Author: Sebastian DrÃge <sebastian droege collabora co uk>
Date:   Wed Oct 24 14:25:01 2012 +0200

    Return correct value for g_socket_get_available_bytes() on Windows and OSX
    
    https://bugzilla.gnome.org/show_bug.cgi?id=686786

 gio/gsocket.c      |   15 ++++++++++---
 gio/tests/socket.c |   53 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 4 deletions(-)
---
diff --git a/gio/gsocket.c b/gio/gsocket.c
index 13dff46..1a8ed50 100644
--- a/gio/gsocket.c
+++ b/gio/gsocket.c
@@ -2368,7 +2368,10 @@ g_socket_check_connect_result (GSocket  *socket,
  * g_socket_get_available_bytes:
  * @socket: a #GSocket
  *
- * Get the amount of data pending in the OS input buffer.
+ * Get the amount of data that can be read from the socket without
+ * blocking. In the case of datagram sockets this returns the size
+ * of the first datagram and not the sum of the sizes of all currently
+ * queued datagrams.
  *
  * Returns: the number of bytes that can be read from the socket
  * without blocking or -1 on error.
@@ -2382,15 +2385,19 @@ g_socket_get_available_bytes (GSocket *socket)
   gulong avail = 0;
 #else
   gint avail = 0;
+  gsize avail_len = sizeof (avail);
 #endif
 
   g_return_val_if_fail (G_IS_SOCKET (socket), -1);
 
-#ifndef G_OS_WIN32
-  if (ioctl (socket->priv->fd, FIONREAD, &avail) < 0)
+#if defined(G_OS_WIN32)
+  if (WSAIoctl (socket->priv->fd, FIONREAD, NULL, 0, &avail, sizeof (avail), 0, 0) == SOCKET_ERROR)
+    return -1;
+#elif defined(SO_NREAD)
+  if (getsockopt (socket->priv->fd, SOL_SOCKET, SO_NREAD, &avail, &avail_len) < 0)
     return -1;
 #else
-  if (ioctlsocket (socket->priv->fd, FIONREAD, &avail) == SOCKET_ERROR)
+  if (ioctl (socket->priv->fd, FIONREAD, &avail) < 0)
     return -1;
 #endif
 
diff --git a/gio/tests/socket.c b/gio/tests/socket.c
index e96e792..5ff5c5e 100644
--- a/gio/tests/socket.c
+++ b/gio/tests/socket.c
@@ -813,6 +813,58 @@ test_unix_connection_ancillary_data (void)
 }
 #endif /* G_OS_UNIX */
 
+static void
+test_datagram_get_available (void)
+{
+  GError *err = NULL;
+  GSocket *server, *client;
+  GInetAddress *addr;
+  GSocketAddress *saddr;
+  gchar data[] = "0123456789abcdef";
+
+  server = g_socket_new (G_SOCKET_FAMILY_IPV4,
+                                G_SOCKET_TYPE_DATAGRAM,
+                                G_SOCKET_PROTOCOL_DEFAULT,
+                                &err);
+  g_assert_no_error (err);
+  g_assert (G_IS_SOCKET (server));
+
+  client = g_socket_new (G_SOCKET_FAMILY_IPV4,
+			 G_SOCKET_TYPE_DATAGRAM,
+			 G_SOCKET_PROTOCOL_DEFAULT,
+			 &err);
+  g_assert_no_error (err);
+  g_assert (G_IS_SOCKET (client));
+
+  addr = g_inet_address_new_any (G_SOCKET_FAMILY_IPV4);
+  saddr = g_inet_socket_address_new (addr, 0);
+
+  g_socket_bind (server, saddr, TRUE, &err);
+  g_assert_no_error (err);
+  g_object_unref (saddr);
+  g_object_unref (addr);
+
+  saddr = g_socket_get_local_address (server, &err);
+  g_assert_no_error (err);
+
+  g_socket_send_to (client, saddr, data, sizeof (data), NULL, &err);
+  g_assert_no_error (err);
+
+  g_assert_cmpint (g_socket_get_available_bytes (server), ==, sizeof (data));
+
+  g_socket_send_to (client, saddr, data, sizeof (data), NULL, &err);
+  g_assert_no_error (err);
+
+  g_assert_cmpint (g_socket_get_available_bytes (server), ==, sizeof (data));
+
+  g_socket_close (server, &err);
+  g_assert_no_error (err);
+
+  g_object_unref (saddr);
+  g_object_unref (server);
+  g_object_unref (client);
+}
+
 int
 main (int   argc,
       char *argv[])
@@ -834,6 +886,7 @@ main (int   argc,
   g_test_add_func ("/socket/unix-connection", test_unix_connection);
   g_test_add_func ("/socket/unix-connection-ancillary-data", test_unix_connection_ancillary_data);
 #endif
+  g_test_add_func ("/socket/datagram_get_available", test_datagram_get_available);
 
   return g_test_run();
 }