vmnetx.ui.view: Fix missing guest mouse cursor in some sessions

We can't use channel.connect() to connect a GObject signal because
SpiceChannel overrides connect() to mean "initiate a TCP connection".
Instead, we were using channel.connect_object(..., channel), but this
creates a reference cycle between the channel PyGObject and the
underlying GObject.  With connect(), the PyGObject would be destroyed
after _new_channel() and recreated (pointing to the same GObject) before
the _request_fd() callback.  With connect_object(), the PyGObject is
referenced from the signal handler closure and so is never freed.
However, if the Python GC runs between _new_channel() and _request_fd(),
it will detect a reference cycle and clear the PyGObject's reference to
the GObject.  This was happening to the cursor channel on RHEL 6;
_request_fd() would receive an invalid PyGObject and then swallow the
resulting TypeError.  As a result, the cursor channel would never be
connected, and the guest cursor (for VMs supporting a hardware cursor)
would always be invisible.

Use connect() instead of connect_object(), explicitly calling it through
the superclass.

vmnetx/ui/view.py

@@ -20,6 +20,7 @@
 from distutils.version import LooseVersion
 import glib
 import gobject
+from gobject import GObject
 import gtk
 import logging
 import pango
@@ -285,23 +286,22 @@ def _connect_viewer(self, password):
         except RuntimeError:
             # No local PulseAudio, etc.
             pass
-        self._session.connect_object('channel-new', self._new_channel,
-                self._session)
+        GObject.connect(self._session, 'channel-new', self._new_channel)
         self._session.open_fd(-1)
 
     def _new_channel(self, session, channel):
         if session != self._session:
             # Stale channel; ignore
             return
-        channel.connect_object('open-fd', self._request_fd, channel)
-        channel.connect_object('channel-event', self._channel_event, channel)
+        GObject.connect(channel, 'open-fd', self._request_fd)
+        GObject.connect(channel, 'channel-event', self._channel_event)
         type = SpiceClientGtk.spice_channel_type_to_string(
                 channel.get_property('channel-type'))
         if type == 'display':
             # Create the display but don't show it until configured by
             # the server
-            channel.connect_object('display-primary-create',
-                    self._display_create, channel)
+            GObject.connect(channel, 'display-primary-create',
+                    self._display_create)
             self._destroy_display()
             self._display_channel = channel
             self._display = SpiceClientGtk.Display(self._session,