Prepare for PHP 8.5

[johnbillion]

This is the meta or "epic" ticket that encapsulates PHP 8.5 compatibility.

Previously:

• #62061 for 8.4
• #59231 for 8.3
• #56009 for 8.2

We're going to try a different approach this time around. All tasks relating to PHP 8.5 compatibility (including devops tasks) will be detailed in and handled in individual tickets. This ticket will remain only in the target milestone for tracking purposes. General info about PHP 8.5 can be added to the summary, and tickets for the actual tasks will be created separately and then linked here.

The previous epic tickets served us really well in the early stages of the corresponding release, but subsequently made it extremely difficult to determine the status of any given change, whether it shipped in any given version, and what is required for compatibility without having to read through the entire ticket. Splitting every required task into a separate ticket with its own acceptance criteria and milestone will help greatly in this regard.

General info

PHP 8.5 is scheduled for release in November 2025. Beta can be expected in August and RC around the end of September.

Tickets

• #63956 - setAccessible deprecations
• #63957 - Using null as array offsets
• #63961 - Updating SimplePie
• #63962 - Fix deprecation notices for __sleep and __wakeup magic methods
• #64008 - Updating sodium_compat
• #64047 - NAN coercion warnings
• #64051 - Updating ID3

[TobiasBg]

PHP 8.5 deprecates non-canonical scalar type casts (boolean|double|integer|binary) deprecated.

In the Core codebase, I found these in 3 separate files, all from external libraries.

For the getID3 library, I created a PR ​upstream.

Two more occurrences are in the IXR and JSON libraries, which are unmaintained and therefore can be updated directly in Core, for which I created this PR:
​https://github.com/WordPress/wordpress-develop/pull/9592

PHP 8.5 deprecates non-canonical scalar type casts (boolean|double|integer|binary). Therefore, their canonical versions should be used.

See ​https://php.watch/versions/8.5/boolean-double-integer-binary-casts-deprecated.

The changes in this commit are the only non-canonical scalar type cases in Core files that are maintained directly.
Another occurrence has been submitted for getID3 ​upstream.

This PR is handled as part of https://core.trac.wordpress.org/ticket/63061.

[TobiasBg]

#63853 adds PHP 8.5 compat array functions: array_first and array_last.

[SergeyBiryukov]

In 60659:

Code Modernization: Replace non-canonical scalar type casts with canonical versions.

PHP 8.5 deprecates four alternative scalar type names in favor of their canonical names:

• boolean → bool
• double → float
• integer → int
• binary → string

References:

• ​PHP.Watch: PHP 8.5: Non-canonical scalar type casts (boolean|double|integer|binary) deprecated
• ​PHP RFC: Deprecations for PHP 8.5: Deprecate non-standard cast names

Follow-up to [1346], [11875].

Props TobiasBg, swissspidy, SergeyBiryukov.
See #63061.

Thanks for the PR! Merged in r60659.

PHP 8.5 deprecates four alternative scalar type names in favor of their canonical names:

• boolean → bool
• double → float
• integer → int
• binary → string

This PR replaces deprecated casts in the bundled JSON, IXR, and ID3 libraries to ensure forward compatibility and avoid deprecation notices.

Follow-up to [60659].
See Trac: https://core.trac.wordpress.org/ticket/63061

Hi there, thanks for the PR!

Please note that getID3 is an external library, and there is already a PR available upstream: ​JamesHeinrich/getID3#469.

[jorbin]

In 60672:

General: Add polyfills for new PHP 8.5 array functions: array_first and array_last.

This power couple of function is coming in PHP 8.5: array_first and array_last.

For more information on these functions, check out the PHP RFC at ​https://wiki.php.net/rfc/array_first_last.

Props tusharbharti, jorbin, peterwilsoncc, mukesh27, johnbillion.
Fixes #63853. See #63061.

[TobiasBg]

Several PHP functions that have not been doing anything since PHP 8.0/8.1 will be deprecated in PHP 8.5 and will thus be throwing warnings: ​https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_no-op_functions_from_the_resource_to_object_conversion

The quickest solution should be to only call them conditionally based on a PHP version check, like

( PHP_VERSION_ID < 80100 ) && finfo_close();
( PHP_VERSION_ID < 80000 ) && xml_parser_free();
( PHP_VERSION_ID < 80000 ) && curl_close();
( PHP_VERSION_ID < 80000 ) && curl_share_close();
( PHP_VERSION_ID < 80000 ) && imagedestroy();

in places where they occur (some of which are in external or "originally-external but now WP" libraries).

[TobiasBg]

Add PHP version check around deprecated functions

[TobiasBg]

I attached a patch that wraps all calls to the mentioned deprecated PHP functions in a PHP version check.

Externally maintained libraries are not included, instead I opened a PR upstream:
SimplePie: ​https://github.com/simplepie/simplepie/pull/937
Requests: ​https://github.com/WordPress/Requests/pull/947

[SergeyBiryukov]

In 60703:

Code Modernization: Address no-op function deprecations in PHP 8.5.

Several PHP functions that have not been doing anything since PHP 8.0/8.1, specifically:

• finfo_close() since the ext/fileinfo migration in PHP 8.1
• xml_parser_free() since the ext/xml migration in PHP 8.0
• curl_close() since the ext/curl migration in PHP 8.0
• curl_share_close() since the ext/curl migration in PHP 8.0
• imagedestroy() since the ext/gd migration in PHP 8.0

will be deprecated in PHP 8.5 and will thus be throwing warnings.

This commit adds conditional checks to only call these functions on the relevant PHP versions.

Reference: ​PHP RFC: Deprecations for PHP 8.5: Deprecate no-op functions from the resource to object conversion.

Props TobiasBg, SergeyBiryukov.
See #63061.

[swissspidy]

I created some sub-tickets for some more issues as originally requested:

• #63956
• #63957

[swissspidy]

In 60729:

Code Modernization: Address reflection no-op function deprecations in PHP 8.5.

Reflection*::setAccessible() methods are no-ops since PHP 8.1. This commit adds conditional checks to only call these functions on older PHP versions.

Reference: ​PHP RFC: Deprecations for PHP 8.5: Deprecate `Reflection*::setAccessible()`.

Props rishabhwp, swissspidy.
Fixes #63956.
See #63061.

[TobiasBg]

SimplePie 1.9.0 with the mentioned PR has been released, see #63961.

[TobiasBg]

Another sub-ticket: #63962
(PHP 8.5: Fix deprecation notices for sleep and wakeup magic methods)

[swissspidy]

In 60741:

Interactivity API: Fix "Cannot use bool as array" error.

Improves PHP 8.5 compatibility where calling list() on an empty array throws a warning.

Props swissspidy, jonsurrell, mukesh27.
Fixes #63977.
See #63061.

[TobiasBg]

#64008 is for updating sodium_compat with a fix for a PHP 8.5 deprecation.

[SergeyBiryukov]

In 60796:

Code Modernization: Address __sleep() and __wakeup() deprecations in PHP 8.5.

PHP 8.5 deprecates the __sleep() and __wakeup() magic methods in favor of __serialize() and __unserialize():

Deprecated: The __wakeup() serialization magic method has been deprecated. Implement __unserialize() instead (or in addition, if support for old PHP versions is necessary)

For PHP < 7.4 compatibility, __sleep() and __wakeup() need to be kept for the time being.

This commit moves the logic of __wakeup() methods in core to __unserialize(), and turns the former into wrappers. WordPress core does not use __sleep() methods, so these are the only changes required.

Reference: ​PHP RFC: Deprecations for PHP 8.5: Deprecate the __sleep() and __wakeup() magic methods.

Follow-up to [56835], [60787], [60795].

Props TobiasBg, tusharbharti, swissspidy, dmsnell, SergeyBiryukov.
Fixes #63962. See #63061.

Trac ticket: https://core.trac.wordpress.org/ticket/63061

[swissspidy]

In 60811:

Code Modernization: Avoid NAN coercion/cast deprecation warnings.

Coercing INF or NAN to a string or casting to int is deprecated in PHP 8.5+.

This change addresses two occurrences in core where this was happening.

Props swissspidy.
Fixes #64047. See #63061.

[swissspidy]

In 60812:

External Libraries: Backport upstream PHP 8.5 fixes for getID3.

In absence of a new release, this cherry-picks ​8cb29233 and ​dbda40de.

Props swissspidy, vidugupta, TobiasBg, desrosj.
Fixes #64051. See #63061.

This is very close. A new issue popped up in SimplePie (​https://github.com/simplepie/simplepie/pull/949) but otherwise tests all pass without failures and errors.

[swissspidy]

In 60952:

Build/Test Tools: Enable testing for PHP 8.5.

With PHP 8.5 due out in November later this year, contributors have been working on ensuring WordPress 6.9 is as compatible as possible. Enough progress has been made during this release cycle where PHPUnit tests now run successfully with no failures reported.

This change enables PHP 8.5 testing throughout Core’s GitHub Action workflows to ensure no new problems are introduced going forward.

Props swissspidy, desrosj.
See #63061.

[desrosj]

Is there anything left outstanding for this one? If everything has been addressed, we should prepare a dev note detailing the changes in 8.5 and how they impact WordPress Core, plugin/theme developers, etc.

[westonruter]

In 61171:

Tests: Fix unit test failure in PHP 8.5 due using null as an array offset.

This adds is_string() type checks for the $post_status arg passed to both get_post_status_object() and is_post_status_viewable(). This was triggered by Tests_Post_IsPostStatusViewable::test_built_in_and_unregistered_status_types() for the null data set.

Follow-up to [61170].

See #63167, #63061.

[jorbin]

With tests passing and no known issues remaining, I think the devnote and updating the ​PHP Compatibility and WordPress Versions page is all the is necessary to declare beta support in 6.9.

This avoids a deprecation warning in PHP 8.5:

Using null as an array offset is deprecated, use an empty string instead

/var/www/src/wp-includes/class-wp-date-query.php:516
/var/www/src/wp-includes/class-wp-date-query.php:170
/var/www/src/wp-includes/class-wp-query.php:2138
/var/www/src/wp-includes/class-wp-query.php:3958
/var/www/src/wp-includes/class-wp.php:704
/var/www/src/wp-includes/class-wp.php:824
/var/www/tests/phpunit/includes/abstract-testcase.php:1346
/var/www/tests/phpunit/includes/testcase-canonical.php:303
/var/www/tests/phpunit/tests/canonical.php:68
/var/www/vendor/bin/phpunit:122

Specifically, the issue is that $wpdb->blogs is null when not on a single-site install. So this ensures that the $wpdb->blogs column is only added to the $known_columns array when on multisite.

It also updates the $valid_columns array to only include multisite-related columns when on multisite, namely registered and last_updated.

Lastly, the phpdoc @var tags for $wpdb->blogs, $wpdb->blogmeta, and the other multisite-specific tables have been updated to indicate they may be null.

Trac ticket: https://core.trac.wordpress.org/ticket/63061

Added a few small nits. I don't think it's in the coding standards, but I prefer to have an empty line before a control structures.

Cool. I'll apply when committing.

I changed the PR description to point to Core-63957 since that's the more specific issue being addressed here.

[westonruter]

In 61191:

Code Modernization: Fix instances of using null as an array offset.

This avoids using multisite-specific tables and columns in WP_Date_Query::validate_column() when on a non-multisite install. Attempting to use $wpdb->blogs as an array index when null on a non-multisite install causes a deprecation notice in PHP 8.5. This also updates the multisite table alias in wpdb to make it clear they could be null.

Developed in ​https://github.com/WordPress/wordpress-develop/pull/10498

Follow-up to [60904], [60809], [37477].

Props westonruter, desrosj.
See #63061.
Fixes #63957.

[desrosj]

With RC1 in ~12 hours and no outstanding known issues, I am going to close this one out as fixed.

If someone would be able and willing to draft a developer note, that would be amazing. If not, I will do my best to get one published this week.

[johnbillion]

• ​Draft make/core post. Let's publish it on November 20th once PHP 8.5 is released.
• ​Draft revision to the PHP Compatibility and WordPress Versions page. Can be published on December 2nd once WordPress 6.9 is released.

[johnbillion]

Dev note published: ​https://make.wordpress.org/core/2025/11/21/php-8-5-support-in-wordpress-6-9/