I was using sync_dbus in a mission-control test to make MC spin its mainloop enough so I could assert one method was not being called before I returned from a call that had previously been made. However, sync_dbus alone was not enough as apparently libdbus returns from Ping calls synchronously so it didn't turn the main loop enough. Calling sync_dbus a few times made it work, but it showed the test was going to be racy. This is what I did:

    # Waste a little time here and there.  We can't call sync_dbus
    # here because it calls Ping and libdbus returns from Ping
    # synchronously and doesn't turn the main loop handle enough.
    call_async(q, cd_props, 'Get', cs.CD_IFACE_OP_LIST, 'DispatchOperations')
    event = q.expect('dbus-return', method='Get')

This works in my case because there was no other Get method call, but it would be bad to replace sync_dbus with this as it could grab the dbus method return from some other call, which is obviously bad.

So, we need a better sync_dbus. Ideas?