Attachment 66610 Details for Bug 54495 – servicetest: don't eavesdrop on method replies or errors

[patch] servicetest: don't eavesdrop on method replies or errors

0001-servicetest-don-t-eavesdrop-on-method-replies-or-err.patch (text/plain), 2.23 KB, created by Simon McVittie on 2012-09-04 16:15:48 UTC

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Creator: Simon McVittie

Created: 2012-09-04 16:15:48 UTC

Size: 2.23 KB

patch

obsolete

>From 4343405fbcb4fe92d39d3cb407529a11b56adde9 Mon Sep 17 00:00:00 2001
>From: Simon McVittie <simon.mcvittie@collabora.co.uk>
>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
>

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