[gtk-vnc] Check if we have a valid socket before trying to close it

[Jonh Wendell <jwendell src gnome org>]

commit 39731831e9167178aef3534bdfe6b6bd6e3ed5f9
Author: Jonh Wendell <jwendell gnome org>
Date:   Fri Aug 27 12:42:24 2010 -0300

    Check if we have a valid socket before trying to close it
    
    If we attempt to destroy the widget while VncConnection still
    is trying to connect to the host, then priv->sock is not valid yet.

 src/vncconnection.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/src/vncconnection.c b/src/vncconnection.c
index 566f4da..736c94e 100644
--- a/src/vncconnection.c
+++ b/src/vncconnection.c
@@ -4397,9 +4397,12 @@ void vnc_connection_shutdown(VncConnection *conn)
 		priv->open_id = 0;
 	}
 
-	g_socket_close(priv->sock, NULL);
-	g_object_unref(priv->sock);
-	priv->sock = NULL;
+	if (priv->sock) {
+		g_socket_close(priv->sock, NULL);
+		g_object_unref(priv->sock);
+		priv->sock = NULL;
+	}
+
 	priv->fd = -1;
 	priv->has_error = 1;
 	VNC_DEBUG("Waking up couroutine to shutdown gracefully");