[glib] GSocket: add some more g_return_if_fail()s

[Claudio Saavedra <csaavedra src gnome org>]

commit f38a1dbca7d68eedc2d75cd7a7947c7217bbbd99
Author: Claudio Saavedra <csaavedra igalia com>
Date:   Wed Jan 4 00:13:50 2012 +0200

    GSocket: add some more g_return_if_fail()s
    
    https://bugzilla.gnome.org/show_bug.cgi?id=667225

 gio/gsocket.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
---
diff --git a/gio/gsocket.c b/gio/gsocket.c
index 661a91b..6bf1213 100644
--- a/gio/gsocket.c
+++ b/gio/gsocket.c
@@ -1727,6 +1727,8 @@ g_socket_check_connect_result (GSocket  *socket,
   guint optlen;
   int value;
 
+  g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
+
   if (!check_socket (socket, error))
     return FALSE;
 
@@ -2692,6 +2694,8 @@ GIOCondition
 g_socket_condition_check (GSocket      *socket,
 			  GIOCondition  condition)
 {
+  g_return_val_if_fail (G_IS_SOCKET (socket), 0);
+
   if (!check_socket (socket, NULL))
     return 0;
 
@@ -2748,6 +2752,8 @@ g_socket_condition_wait (GSocket       *socket,
 			 GCancellable  *cancellable,
 			 GError       **error)
 {
+  g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
+
   if (!check_socket (socket, error))
     return FALSE;
 
@@ -2919,6 +2925,8 @@ g_socket_send_message (GSocket                *socket,
   GOutputVector one_vector;
   char zero;
 
+  g_return_val_if_fail (G_IS_SOCKET (socket), -1);
+
   if (!check_socket (socket, error))
     return -1;
 
@@ -3238,6 +3246,8 @@ g_socket_receive_message (GSocket                 *socket,
   GInputVector one_vector;
   char one_byte;
 
+  g_return_val_if_fail (G_IS_SOCKET (socket), -1);
+
   if (!check_socket (socket, error))
     return -1;