From 4343405fbcb4fe92d39d3cb407529a11b56adde9 Mon Sep 17 00:00:00 2001 From: Simon McVittie Date: Fri, 31 Aug 2012 19:49:30 +0100 Subject: [PATCH 1/4] servicetest: don't eavesdrop on method replies or errors Eavesdropping on method replies breaks libdbus if you call methods using the same connection. You can get into a situation like this: * Test calls a method on MC; say the serial number is 42 * At around the same time, MC calls a method on gnome-keyring and also uses serial number 42 * gnome-keyring replies, labelled "in reply to 42" * Test is eavesdropping, so it sees the reply going from gnome-keyring to MC * Test interprets the reply from gnome-keyring to MC as the reply it was expecting from MC, sees completely the wrong types, and becomes confused This seems unlikely - but because serial numbers are sequential and start from 1 for each connection (as opposed to starting from a random offset), two connections can quite easily happen to sync up. I saw it happen most recently in the gnome-keyring test. With the benefit of hindsight, I think I've seen this before: whenever the tests made an Introspect() call which returned a type other than 's', that was probably this bug. We never actually generated events for messages other than signals and method calls, so match those ones specifically, and don't eavesdrop on replies. --- tests/twisted/servicetest.py | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tests/twisted/servicetest.py b/tests/twisted/servicetest.py index c0c63ed..6041831 100644 --- a/tests/twisted/servicetest.py +++ b/tests/twisted/servicetest.py @@ -316,12 +316,12 @@ class IteratingEventQueue(BaseEventQueue): try: # for dbus > 1.5 - bus.add_match_string("eavesdrop=true") + bus.add_match_string("eavesdrop=true,type='signal'") except dbus.DBusException: - pass - - # for dbus 1.4 - bus.add_match_string("") + bus.add_match_string("type='signal'") + bus.add_match_string("type='method_call'") + else: + bus.add_match_string("eavesdrop=true,type='method_call'") bus.add_message_filter(self._dbus_filter_bound_method) -- 1.7.10.4