Bug #49490 [Asn->Csd]: XPath namespace prefix conflict
Edit report at http://bugs.php.net/bug.php?id=49490&edit=1
ID: 49490
Updated by: rrichards@php.net
Reported by: olav dot morken at uninett dot no
Summary: XPath namespace prefix conflict
-Status: Assigned
+Status: Closed
Type: Bug
Package: DOM XML related
Operating System: Linux (Debian)
PHP Version: 5.3.0
Assigned To: rrichards
New Comment:
This bug has been fixed in SVN.
Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
Thank you for the report, and for helping us make PHP better.
Automatic namespace registration really wasn't a good idea from the get
go.
Performance starts taking a hit the deeper in the tree a context node.
The patch
in the bug report was not used; rather a new third argument has been
added to
the query() and evalute() methods, which allows automatic registration
of the
context node to be disabled. For BC reasons auto registration is enabled
by
default. When auto registration is disabled and context nodes are used
XPath
performance will be increased.
i.e.
echo($xp->query('//prefix:root', null, false)->length . "\n");
Previous Comments:
------------------------------------------------------------------------
[2010-05-04 17:41:51] rrichards@php.net
Automatic comment from SVN on behalf of rrichards
Revision: http://svn.php.net/viewvc/?view=revision&revision=298974
Log: fix bug #49490 (XPath namespace prefix conflict)
add test
------------------------------------------------------------------------
[2010-04-17 11:14:50] thomas at weinert dot info
It looks like DOMXPath->evaluate()/DOMXPath->query() registers the
namespace prefixes of the given context and overrides any definition
from DOMXPath->registerNamespace(). PHP should not register any
namespaces from the context or at least prefer manual registrations over
automatic.
Reproduce code:
---------------
$dom = new DOMDocument();
$dom->loadXML(
'<foobar><a:foo xmlns:a="urn:a">'.
'<b:bar xmlns:b="urn:b"/></a:foo>'.
'</foobar>'
);
$xpath = new DOMXPath($dom);
//get context node and check "a:foo"
$context = $dom->documentElement->firstChild;
var_dump($context->tagName);
// try to override the context node
$xpath->registerNamespace('a', 'urn:b');
var_dump(
$xpath->evaluate(
'descendant-or-self::a:*',
$context
)->item(0)->tagName
);
// use a prefix not used in context
$xpath->registerNamespace('prefix', 'urn:b');
var_dump(
$xpath->evaluate(
'descendant-or-self::prefix:*',
$context
)->item(0)->tagName
);
Expected result:
----------------
string(5) "a:foo"
string(5) "b:bar"
string(5) "b:bar"
Actual result:
----------------
string(5) "a:foo"
string(5) "a:foo"
string(5) "b:bar"
------------------------------------------------------------------------
[2009-09-07 08:41:26] olav dot morken at uninett dot no
Description:
------------
When processing an XML document with namespaces, an XPath query for a
node with a different namespace but the same namespace prefix fails.
This appears to be a conflict between the XPath namespaces and the
document namespaces. It works if either:
- The prefix in the query is replaced with a prefix that doesn't
exist in the document.
- If the prefix in the query matches the prefix in the document.
This was tested with:
- PHP 5.3 from debian experimental: 5.3.0-3
- libxml2 2.7.3.dfsg-2.1
Reproduce code:
---------------
$doc = new DOMDocument();
$doc->loadXML('<prefix:root xmlns:prefix="urn:a" />');
$xp = new DOMXPath($doc);
$xp->registerNamespace('prefix', 'urn:b');
echo($xp->query('//prefix:root')->length . "\n");
Expected result:
----------------
It should not find the root node, since we ask for a node in a different
prefix. I.e. it should print '0'.
Actual result:
--------------
It finds the root node, i.e. it prints '1'.
------------------------------------------------------------------------
--
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