0004620: Quercus passes 'by value object' as 'reference'

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Category

Severity

Reproducibility

Date Submitted

Last Update

0004620

[Quercus]

minor

always

06-16-11 08:56

03-12-13 12:22

Reporter

thr

View Status

public

Assigned To

nam

Priority

normal

Resolution

unable to reproduce

Platform

Status

closed

Projection

none

OS Version

ETA

none

Fixed in Version

Product Version

4.0.14

Product Build

Summary

0004620: Quercus passes 'by value object' as 'reference'

Description

Setting up Wordpress 3.1.3 on Quercus after making some quirks to get it run (Issue 0004568 and Issue 0004612) I get it working. Only if I signed in as admin and Under the menu Item where all articels are listed, I found a difference to a 'normal' php wordpress installation. All the links below the artikel list, which will allow you to edit, delete, etc, the articels, all my links where gone, like I do not have permission to edit.

Investigating the problem I found that Wordpress is using a function called 'wp_list_pluck' to reduce a big array of article-type definitions to a single value.

Thru some calls Wordpress passed the object $wp_post_types to this function.
This function then returns one field out of this object.
As this list is assigning a new value to one of the function parameters and returning it to the callee, I found after thre calls the original $wp_post_types was modfied/damaged.
As php is passing the object by value, this should not be possible. Under some circumstances Quercus seems to pass this object as reference.

To fix this, I changed the funtion in Wordpress to use a new variable to return the result instead of the function parameter.

Unfortunately I could not simulate the behaviour in a simple test script. But anyway I might want to have a look to understand the principle problem ...
but there must be happening more in wordpress to cause this .....

Steps To Reproduce

Additional Information

/**
* Pluck a certain field out of each object in a list
*
* @since 3.1.0
*
* @param array $list A list of objects or arrays
* @param int|string $field A field from the object to place instead of the entire object
* @return array
*/
function wp_list_pluck( $list, $field ) {
    foreach ( $list as $key => $value ) {
        $value = (array) $value;
        $list[ $key ] = $value[ $field ];
    }

    return $list;
}

CHANEGED To:

function wp_list_pluck( $list, $field ) {
    foreach ( $list as $key => $value ) {
        $value = (array) $value;
        $new_list[ $key ] = $value[ $field ];
    }

    return $new_list;
}

Attached Files

test_array_ref.php [^] (11,500 bytes) 06-16-11 08:56

Relationships

Notes
(0005684) krystian 01-30-12 11:35	I can also confirm it is still the case in Resin 4.0.24

(0006130) nam 12-30-12 00:13	Unable to reproduce in 4.0.33. Tried wordpress-3.1.3, wordpress-3.5, and your attached script. We did fix a few value-vs-reference issues starting over the course of the last 6 months.

Issue History
Date Modified	Username	Field	Change
06-16-11 08:56	thr	New Issue
06-16-11 08:56	thr	File Added: test_array_ref.php
06-18-11 06:02	kdecherf	Issue Monitored: kdecherf
01-30-12 11:35	krystian	Note Added: 0005684
12-30-12 00:13	nam	Note Added: 0006130
03-12-13 12:22	nam	Status	new => assigned
03-12-13 12:22	nam	Assigned To	=> nam
03-12-13 12:22	nam	Status	assigned => closed
03-12-13 12:22	nam	Resolution	open => unable to reproduce

Mantis 1.0.0rc3[^]

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