Bug #79701 [Opn->Ver]: getElementById does not correctly work with duplicate definitions
Edit report at https://bugs.php.net/bug.php?id=79701&edit=1
ID: 79701
Updated by: cmb@php.net
Reported by: beberlei@php.net
Summary: getElementById does not correctly work with
duplicate definitions
-Status: Open
+Status: Verified
Type: Bug
Package: DOM XML related
PHP Version: 7.2.31
Block user comment: N
Private report: N
New Comment:
Confirmed: <https://3v4l.org/Ols6m>
Previous Comments:
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[2020-06-15 02:17:41] beberlei@php.net
Description:
------------
A DOM id element is supposed to be unique, but sometimes the world is messy. The DOM specification
says:
> The getElementById(elementId) method, when invoked, must return the first element,
> in tree order, within thisâs descendants, whose ID is elementId, and null if there
> is no such element otherwise.
PHP uses libxmls ID Map functionality, which does not allow duplicates. The return value of
"xmlAddID" is not checked for the error, so elements with duplicate ID don't cause a
problem.
However if you remove the first element with an ID, or re-order the elements, then the
specifications assumption of returning the first element in tree order does not work anymore.
Test script:
---------------
<?php
$dom = new DOMDocument();
$root = $dom->createElement('html');
$dom->appendChild($root);
$el1 = $dom->createElement('p1');
$el1->setAttribute('id', 'foo');
$el1->setIdAttribute('id', true);
$root->appendChild($el1);
$el2 = $dom->createElement('p2');
$el2->setAttribute('id', 'foo');
$el2->setIdAttribute('id', true);
$root->appendChild($el2);
unset($el1, $el2);
$root->removeChild($dom->getElementById('foo'));
var_dump($dom->getElementById('foo'));
Expected result:
----------------
Returns Element <p2 id="foo" />
Actual result:
--------------
NULL
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=79701&edit=1
Thread (2 messages)