#1039: Work around random XPath result set corruption bugs in certain libxml
versions
----------------------+-----------------------------------------------------
Reporter: david | Owner: david
Type: defect | Status: new
Priority: normal | Milestone: 1.0
Component: config | Version: 1.0.0beta1
Severity: critical | Keywords:
Has_patch: 0 |
----------------------+-----------------------------------------------------
Affected libxml versions: at least up to and including 2.6.26.
It is random, not really reproducible. Just happens after a bunch of
requests.
One of the affected handlers is {{{AgaviLoggingConfigHandler}}}: in
{{{logging.xml}}}, {{{<appender>}}} elements occur directly inside
{{{<configuration>}}}, and also inside {{{<logger>}}} elements.
The code does:
{{{
foreach($cfg->get('loggers') as $logger) {
}}}
which, in turn, will run this XPath (namespace URIs omitted for brevity):
{{{
child::*[local-name() = "logger" and namespace-uri() = "..."] | child
::*[local-name() = "loggers" and namespace-uri() = "..."]/*[local-name() =
"logger" and namespace-uri() = "..."]
}}}
This xpath is run on the given element, in our case, that's {{{$cfg}}},
the {{{<configuration> element. The {{{child}}} axis retrieves only direct
children of an element, not other descendants.
Yet, sometimes (in around 1 out of 10 to 20 times),
{{{<appender>}}} elements from inside {{{<logger>}}} will be in the result
set:
{{{
#!xml
<?xml version="1.0" encoding="UTF-8"?>
<configurations xmlns="http://agavi.org/agavi/1.0/config";>
<configuration>
<loggers default="debug">
<logger name="debug" class="AgaviLogger"
level="AgaviLogger::ALL">
<appenders>
<appender>DebugLogAppender</appender>
</appenders>
</logger>
</loggers>
<appenders>
<appender name="DebugLogAppender"
class="AgaviRotatingFileLoggerAppender" layout="DateTimeLayout">
<parameters>
<parameter
name="dir">%core.app_dir%/log/</parameter>
<parameter
name="prefix">debug-</parameter>
</parameters>
</appender>
</appenders>
<layouts>
<layout name="DateTimeLayout"
class="AgaviTimestampLoggerLayout" />
</layouts>
</configuration>
</configurations>
}}}
is then compiled to:
{{{
#!php
<?php
${'_layout_DateTimeLayout'} = new AgaviTimestampLoggerLayout();
${'_layout_DateTimeLayout'}->initialize($this->context, array (
));
${'_appender_'} = new ();
${'_appender_'}->initialize($this->context, array (
));
${'_appender_'}->setLayout(${'_layout_'});
${'_appender_DebugLogAppender'} = new AgaviRotatingFileLoggerAppender();
${'_appender_DebugLogAppender'}->initialize($this->context, array (
'dir' => 'D:\\workspace\\Kauppapaikka\\app/log/',
'prefix' => 'debug-',
));
${'_appender_DebugLogAppender'}->setLayout(${'_layout_DateTimeLayout'});
${'_logger_debug'} = new AgaviLogger();
${'_logger_debug'}->setAppender('DebugLogAppender',
${'_appender_DebugLogAppender'});
${'_logger_debug'}->setAppender('AdtRequestLogAppender',
${'_appender_AdtRequestLogAppender'});
${'_logger_debug'}->setLevel(AgaviLogger::ALL);
$this->setLogger('debug', ${'_logger_debug'});
$this->setDefaultLoggerName('debug');
}}}
Some debugging clearly proved that this happens because the node set from
the {{{$cfg->get('loggers')}}} call contains
{{{<appender>DebugLogAppender</appender>}}} from the {{{<logger>}}}.
--
Ticket URL: <http://trac.agavi.org/ticket/1039>
Agavi <http://www.agavi.org/>
An MVC Framework for PHP5
_______________________________________________
Agavi Tickets Mailing List
[email protected]
http://lists.agavi.org/mailman/listinfo/tickets
