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Undefined Array Key with a Key as a Long String #13279
Description
Description
The following code:
<?php
class array_test
{
public $array = array();
public function __construct()
{
$this->array = array(
'1696007099_5_d386ca263816163166823ef00979d944' => array(
'order' => 1
),
'1663066269_5_8c82ae69264d73f7ae7ce3a619501231' => array(
'order' => 0
)
);
uksort($this->array, function ($a, $b)
{
return $this->array[$a]['order'] - $this->array[$b]['order'];
}
);
}
}
new array_test;Resulted in this output:
Warning: Undefined array key "1696007099_5_d386ca263816163166823ef00979d944" in .../array_test.php on line 19
But I expected this output instead:
No warnings/errors, just a freshly sorted array.
I have tested the following:
echo $a; // 1696007099_5_d386ca263816163166823ef00979d944
echo $b; // 1663066269_5_8c82ae69264d73f7ae7ce3a619501231
echo array_key_exists($a, $this->array); // FALSE
echo isset($this->array[$a]); // FALSE
echo array_key_first($this->array); // 1696007099_5_d386ca263816163166823ef00979d944
echo array_keys($this->array)[0]; // 1696007099_5_d386ca263816163166823ef00979d944
PHP Version
PHP 8.3
Operating System
CentOS 7.9
Activity
iluuu1994 commentedon Jan 30, 2024
I don't see this warning. How are you running this code? Just in a CLI script?
designextreme commentedon Jan 30, 2024
I've attempted to simplify the PHP contained within a large script and may have failed in the process. I think I missed something with the array...
designextreme commentedon Jan 30, 2024
The example code is a simplified version of a WordPress plugin. It's really odd how array values can't be accessed by the keys here, yet they do exist. It is covered in a forum post at: WordPress.org. This is only in PHP 8.3, not 8.2,
In the meantime, I will try to create a simple version so you can replicate it.
SVGAnimate commentedon Jan 30, 2024
The mbstring extension has changed. I bet that's it.
designextreme commentedon Jan 30, 2024
@SVGAnimate I think you're on to something. The actual array does contain emoticons and more besides. I am still attempting to create the "simple" version using the review data from the WordPress plugin.
6 remaining items
iluuu1994 commentedon Jan 31, 2024
I think this would be possible if the string is placed in the wrong bucket, i.e. if it was originally saved in one bucket and then the string+hash change. I suppose this could happen if there was a refcounting bug where the string is modified in-place.
But let's wait for your reproducer.
designextreme commentedon Jan 31, 2024
Got it! Here is the simplified example:
I did try this with some multi-byte characters and emoticons, but this didn't affect the outcome.
SVGAnimate commentedon Jan 31, 2024
On PHP 8.3.1 i do not have Notice/Warning
iluuu1994 commentedon Jan 31, 2024
Hmm yes. This is caused by #11060. The issue is that during the user call, the array is essentially unstable. I think this should be reverted for
php_usort. /cc @nielsdos (I'm creating a PR)designextreme commentedon Jan 31, 2024
With PHP 8.3.2, here are the log entries:
Fix instable array during in-place modification in uksort
Fix instable array during in-place modification in uksort