Created attachment 28175 [details] [review]
Patch to register self._refresh instead of self.update_handler

Using at-spi2-core and at-spi2-atk from git master I performed the following in this order:

1) Launched at-spi-registryd in one shell
2) Launched Orca in another shell:
   PYTHONPATH=~/work/at-spi-dbus/bld/lib/python2.4/site-packages ./bld/bin/orca
3) Launched galctool in a third shell:
   gcalctool --gtk-module=gail:~/work/at-spi-dbus/bld/lib/gtk-2.0/modules/libspiatk.so

As soon as I launched gcalctool, Orca complained:

ERROR:dbus.connection:Exception in handler for D-Bus signal:
Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/dbus/connection.py", line 214, in maybe_handle_message
TypeError: update_handler() takes exactly 3 arguments (1 given)

When I look at applicationcache.py, I see update_handler is defined as so:

def update_handler (self, update_type, bus_name):

and I see it registered as so:

self._regsig = connection.add_signal_receiver(
                   self.update_handler,
                   dbus_interface=ATSPI_REGISTRY_INTERFACE,
                   signal_name="updateApplications")

When I redefined update_handler temporarily as so:

def update_handler (self, update_type=None, bus_name=None):
    print "HERE", update_type, bus_name
    ...

I see that update_type and bus_name are None.  So, I suspect something unintended is happening here.

If I pass self._refresh instead of self.update_handler to add_signal_receiver, it seems to eliminate the problem. But, I'm not sure this is the right thing to do:

self._regsig = connection.add_signal_receiver(
                   self._refresh,
                   dbus_interface=ATSPI_REGISTRY_INTERFACE,
                   signal_name="updateApplications")