Performance Hints error: null passed to delete_by_url() when string expected

[joejoe04]

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• Made sure you’re on the latest version ✅
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Describe the bug
Users on 3.16.4 reporting the following error being logged:

[14-Aug-2024 17:34:32 UTC] PHP Fatal error: Uncaught TypeError: Argument 1 passed to WP_Rocket\Engine\Common\PerformanceHints\Admin\Controller::delete_by_url() must be of the type string, null given, called in /home/customer/www/mabelkatz.com/public_html/espanol/wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php on line 81 and defined in /home/customer/www/mabelkatz.com/public_html/espanol/wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php:177
Stack trace:
#0 /home/customer/www/mabelkatz.com/public_html/espanol/wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php(81): WP_Rocket\Engine\Common\PerformanceHints\Admin\Controller->delete_by_url(NULL)
#1 /home/customer/www/mabelkatz.com/public_html/espanol/wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Subscriber.php(64): WP_Rocket\Engine\Common\PerformanceHints\Admin\Controller->delete_post(187146)
#2 /home/customer/www/mabelkatz.com/public_html/espanol/wp-includes/class-wp-hook.php(326 in /home/customer/www/mabelkatz.com/public_html/espanol/wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php on line 177

It's related to attachments and this bit of code:

wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php

Lines 75 to 82 in d499588

	$url = get_permalink( $post_id );
	if ( false === $url ) {
	return;
	}
	$this->delete_by_url( $url );
	}

It seems some plugins are returning null for attachment $urls. The code above only returns if $url is exactly false, allowing null to get past.

Could instead do something like this:

if ( ! is_string( $url ) {
  return;
}

To Reproduce
Steps to reproduce the behavior:

1. Be on version 3.16.4 and use any plugin that returns null for attachment URLs

We're not sure exactly which plugins are doing this, but we have 3 cases reported so far that use a variety of different plugins.

@wordpressfan said it can be reproduced with this:

add_filter( 'attachment_link', function ( $permalink, $post_id ) {
    if ( 'attachment' === get_post_type( $post_id ) ) {
        return;
    }
    return $permalink;
}, 10, 2 );

Expected behavior
Any time the $url value is not a string, we should return to stop processing.

Additional context
Slack: https://wp-media.slack.com/archives/C43T1AYMQ/p1723658183566389
Case1: https://secure.helpscout.net/conversation/2679645797/507641/
Case2: https://secure.helpscout.net/conversation/2684619765/508416/
Case3: https://secure.helpscout.net/conversation/2685184550/508504/

Acceptance Criteria (for WP Media team use only)
Clear instructions for developers, to be added before the grooming

[webtrainingwheels]

Another case: https://secure.helpscout.net/conversation/2691146803/509495?folderId=377611

[sandyfigueroa]

Another case: https://secure.helpscout.net/conversation/2696774398/510478/

[kskonovalov]

Faced the same issue preventing upload any media or plugins, error
Uncaught TypeError: WP_Rocket\Engine\Common\PerformanceHints\Admin\Controller::delete_by_url(): Argument #1 ($url) must be of type string, null given, called in wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php

Uploading media work again if deactivate WPRocket

Another way is a hotfix until it's fixed by plugin's authors

in
wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php

replace the delete_by_url method with

private function delete_by_url( $url ) {
    if(is_string($url)) {
      foreach ($this->factories as $factory) {
        $factory->queries()->delete_by_url(untrailingslashit($url));
      }
    }
}

[alfonso100]

another case here https://secure.helpscout.net/conversation/2706213063/512091?folderId=273766

[Adrianadla]

Seem related https://secure.helpscout.net/conversation/2705723846/511994?folderId=8127822

[joejoe04]

Related: https://secure.helpscout.net/conversation/2712922741/513249/

[juricazuanovic]

Related: https://secure.helpscout.net/conversation/2717613774/514189

[joejoe04]

Related: https://secure.helpscout.net/conversation/2717696193/514198

[alfonso100]

In 2 additional cases, users can also see the following message in the media uploader:

When trying to upload an image, we get the error in the WP Media screen of:
The server cannot process the image. This can happen if the server is busy or does not have enough resources to complete the task. Uploading a smaller image may help. Suggested maximum size is 2560 pixels.

And the error reported appears in the logs:

[12-Sep-2024 19:18:22 UTC] PHP Fatal error:  Uncaught TypeError: WP_Rocket\\Engine\\Common\\PerformanceHints\\Admin\\Controller::delete_by_url(): Argument #1 ($url) must be of type string, null given, called in public_html/wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php on line 81 and defined in /wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php:177\
  thrown in /wp-content/plugins/wp-rocket/inc/Engine/Common/PerformanceHints/Admin/Controller.php on line 177\

tickets:
https://secure.helpscout.net/conversation/2706213063/512091
https://secure.helpscout.net/conversation/2718520629/514450/