PHP 8.1 `ltrim()` Compatibility Issue

[timnolte]

https://github.com/google/site-kit-wp/blob/b5b3f4a0c227a308ceddcc8345a6e87fc3385e3a/includes/Modules/Tag_Manager.php#L213

Since the trim() call prior to the ltrim() call can return null there is no verification check to ensure that null isn't being passed to ltrim() and thus a deprecation notice is thrown.

Deprecated: ltrim(): Passing null to parameter #1 ($string) of type string is deprecated

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Acceptance criteria

• Site Kit should not raise PHP deprecation notices on PHP 8.1 due to incorrect ltrim usage.

Implementation Brief

Test Coverage

QA Brief

Changelog entry

[timnolte]

I'll get a PR opened for a fix for this. I've tested it and a simple validation before the call is all that is needed.

[kuasha420]

Thank you for raising the issue @timnolte ! Can you provide a step to reproduce this issue? Cheers!

[mrwweb]

I'm getting the error:

ltrim(): Passing null to parameter #1 ($string) of type string is deprecated

Environment: WordPress 6.4.1 on PHP 8.1.25. The error appears both in the dashboard and on the front-end.

Here's a full stacktrace with identifying stuff redacted:

wp-includes/formatting.php:4494 ltrim() wp-includes/formatting.php:4494 esc_url() wp-includes/formatting.php:4620 sanitize_url() wp-includes/formatting.php:4602 esc_url_raw() wp-content/plugins/google-site-kit/includes/Core/Assets/Assets.php:716 Google\S\C\A\Assets->get_inline_base_data() wp-content/plugins/google-site-kit/includes/Core/Assets/Assets.php:356 Google\S\C\A\Assets->Google\S\C\A{closure}() wp-content/plugins/google-site-kit/includes/Core/Assets/Assets.php:356 Google\S\C\A\Script_Data->Google\S\C\A{closure}() wp-content/plugins/google-site-kit/includes/Core/Assets/Script_Data.php:51 Google\S\C\A\Asset->before_print() wp-content/plugins/google-site-kit/includes/Core/Assets/Assets.php:1016 Google\S\C\A\Assets->run_before_print_callbacks() wp-content/plugins/google-site-kit/includes/Core/Assets/Assets.php:1025 Google\S\C\A\Assets->run_before_print_callbacks() wp-content/plugins/google-site-kit/includes/Core/Assets/Assets.php:1025 Google\S\C\A\Assets->run_before_print_callbacks() wp-content/plugins/google-site-kit/includes/Core/Assets/Assets.php:1025 Google\S\C\A\Assets->run_before_print_callbacks() wp-content/plugins/google-site-kit/includes/Core/Assets/Assets.php:155 Google\S\C\A\Assets->Google\S\C\A{closure}() wp-includes/class-wp-hook.php:324 do_action('wp_print_scripts') wp-includes/script-loader.php:2214 wp_print_head_scripts() wp-includes/class-wp-hook.php:324 do_action('wp_head') wp-includes/general-template.php:3052 wp_head() wp-content/themes/{theme}/header.php:20 load_template('wp-content/themes/{theme}/header.php') wp-includes/template.php:725 locate_template() wp-includes/general-template.php:48 get_header() wp-content/themes/{theme}/singular.php:15

I'll note that this doesn't seem to be exactly the same as @timnolte's fix, so it's possible this error is in a few different places.

Here is my Site Kit info from Tools > Site Health with identifying stuff removed

Version	1.113.0
PHP Version	8.1.25
WordPress Version	6.4.1
AMP Mode	No
Site Status	Connected through site credentials
User Status	Authenticated
Verification Status	Verified through file
Connected user count	1
Active Modules	Site Verification, Search Console, Analytics, Analytics 4, PageSpeed Insights, Tag Manager
Recoverable Modules	None
Required scopes
openid: ✅
https://www.googleapis.com/auth/userinfo.profile: ✅
https://www.googleapis.com/auth/userinfo.email: ✅
https://www.googleapis.com/auth/siteverification: ✅
https://www.googleapis.com/auth/webmasters: ✅
https://www.googleapis.com/auth/analytics.readonly: ✅
https://www.googleapis.com/auth/tagmanager.readonly: ✅
User Capabilities
googlesitekit_authenticate: ✅
googlesitekit_setup: ✅
googlesitekit_view_posts_insights: ✅
googlesitekit_view_dashboard: ✅
googlesitekit_manage_options: ✅
googlesitekit_update_plugins: ✅
googlesitekit_view_splash: ✅
googlesitekit_view_authenticated_dashboard: ✅
googlesitekit_view_wp_dashboard_widget: ✅
googlesitekit_view_admin_bar_menu: ✅
googlesitekit_view_shared_dashboard: ⭕
googlesitekit_read_shared_module_data::["search-console"]: ⭕
googlesitekit_read_shared_module_data::["analytics"]: ⭕
googlesitekit_read_shared_module_data::["analytics-4"]: ⭕
googlesitekit_read_shared_module_data::["pagespeed-insights"]: ⭕
googlesitekit_manage_module_sharing_options::["search-console"]: ✅
googlesitekit_manage_module_sharing_options::["analytics"]: ✅
googlesitekit_manage_module_sharing_options::["analytics-4"]: ✅
googlesitekit_manage_module_sharing_options::["pagespeed-insights"]: ✅
googlesitekit_delegate_module_sharing_management::["search-console"]: ✅
googlesitekit_delegate_module_sharing_management::["analytics"]: ✅
googlesitekit_delegate_module_sharing_management::["analytics-4"]: ✅
googlesitekit_delegate_module_sharing_management::["pagespeed-insights"]: ⭕
Features
adsenseSetupV2: ✅
enhancedMeasurement: ✅
ga4Reporting: ✅
gm3Components: ⭕
keyMetrics: ⭕
Search Console Shared Roles	None
Search Console Management	Owner
Analytics Shared Roles	None
Analytics Management	Owner
Analytics 4 Shared Roles	None
Analytics 4 Management	Owner
PageSpeed Insights Shared Roles	None
PageSpeed Insights Management	Any admin signed in with Google
Analytics snippet placed	Yes
Analytics 4 snippet placed	Yes
Tag Manager AMP container ID	None
Tag Manager snippet placed	Yes

[adamdunnage]

@mrwweb Thanks for your comment. We don't provide support via GitHub but we'd be delighted to assist you with this in the Site Kit support forum. Please can you open a new support topic and share the details you have done so here. Thanks and we look forward to helping you with this!

[timnolte]

@adamdunnage this isn't in need of some additional support forum request. This is a code issue that needs to be fixed, which I already provided a PR to fix this. The output that @mrwweb provided are the details to traceback this depreciation notice. This is a PHP 8.1 compatibility issue not an end user issue.

[timnolte]

@mrwweb just noticed that your stack trace does appear to call out the ltrim() in WordPress Core. Have you taken a look at the code called out in each line of the stack trace? If not I can take a look to determine if I can update my PR to include fixing this as well. I'm suspecting that this may be partly do an incomplete plugin setup, and there isn't adequate validation happening.

[mrwweb]

@timnolte Haven't done anything else. I saw the error, found this issue, and saw the request for a stacktrace and dumped it here. Hope it's useful!

[kevinlisota]

This issue still exists in Site Kit. I get the deprecation warning in both PHP 8.1 and 8.2 on every page load with stack trace results like originally reported.

[mxbclang]

@kevinlisota Yes, this issue remains open at the moment, but it's on our list to fix in a future release. Feel free to follow along here for updates. Thanks!

[zutigrm]

Wasn't able to reproduce it, tested on InstaWP using PHP 8.1 and 8.2, with and without Tag manager being active. Couldn't see a scenario where $name would be empty 🤔

Unassigning myself so someone else can try as well