Bug #52373 [Com]: XPath returns inconsistent results
Edit report at http://bugs.php.net/bug.php?id=52373&edit=1
ID: 52373
Comment by: bugs dot php dot net at moesen dot nu
Reported by: david at sickmiller dot com
Summary: XPath returns inconsistent results
Status: Open
Type: Bug
Package: DOM XML related
Operating System: Cent OS 5
PHP Version: 5.2.13
Block user comment: N
New Comment:
I cannot reproduce this either.
$ cat /etc/issue
Debian GNU/Linux squeeze/sid \n \l
$ php --version
PHP 5.3.3-0.dotdeb.0 with Suhosin-Patch (cli) (built: Jul 24 2010
01:12:50)
$ dpkg --list | grep libxml2
ii libxml2 2.7.7.dfsg-2 GNOME XML library
Previous Comments:
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[2010-07-19 09:09:44] david at sickmiller dot com
I wonder if this may be related to the libxml2 library. I am using
v2.6.26-2.1.2.8 from the CentOS distribution.
------------------------------------------------------------------------
[2010-07-19 07:59:35] m dot philipp at coreto dot de
Cannot repeat with php 5.3.2.
All test runs resulted in:
"In 10000 instances, found 1 match(es) for
/root[1]/field[@attr1='val1']"
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[2010-07-19 01:37:51] david at sickmiller dot com
Description:
------------
Sometimes the DOMXpath->evaluate() function returns unreliable results.
This seems to happen when the document has at least a depth of 3 and
selectors are used at multiple levels. There may be other conditions
that trigger it; I'm not sure. The test script below is consistently
showing errors for me.
Test script:
---------------
<?php
$rawxml = '<?xml version="1.0"?><root><field
attr1="val1"><field
attr1="val1"/></field></root>';
$rawxpath = "/root[1]/field[@attr1='val1']";
$results = array();
for ($i = 0; $i < 10000; $i++) {
$xmlDocument = new DOMDocument();
$xmlDocument->loadXML($rawxml);
$xp = new DOMXPath($xmlDocument);
$xpr = $xp->evaluate($rawxpath, $xmlDocument->documentElement);
if (isset($results[(string) $xpr->length]))
$results[(string) $xpr->length]++;
else
$results[(string) $xpr->length] = 1;
}
foreach ($results as $matches => $count)
printf("In %5d instances, found $matches match(es) for
$rawxpath\n", $count);
Expected result:
----------------
In 10000 instances, found 1 match(es) for /root[1]/field[@attr1='val1']
Actual result:
--------------
The exact numbers seem to vary, but I get roughly this response:
In 9924 instances, found 1 match(es) for /root[1]/field[@attr1='val1']
In 76 instances, found 2 match(es) for /root[1]/field[@attr1='val1']
------------------------------------------------------------------------
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Edit this bug report at http://bugs.php.net/bug.php?id=52373&edit=1
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