Call to `_admin_bar_bump_cb` causes deprecation error in WordPress 6.4+

Bug Description

The call to _admin_bar_bump_cb at https://github.com/ampproject/amp-wp/blob/2c4df9e1dec74c798e11f06cd02e470f1f988705/includes/class-amp-theme-support.php#L1226C9-L1226C9 causes PHP Deprecation notices to appear when using the AMP plugin with WordPress 6.4+.

The entire notice is:

PHP Deprecated:  Function _admin_bar_bump_cb is deprecated since version 6.4.0! Use wp_enqueue_admin_bar_bump_styles instead. in /var/www/html/wp-includes/functions.php on line 6032

It seems using wp_enqueue_admin_bar_bump_styles instead will fix the issue, when the version of WordPress is equal-to/above 6.4.0.

Expected Behaviour

No deprecation errors appear in the WordPress debug log/elsewhere when using the AMP plugin with WordPress 6.4+.

Screenshots

PHP Version

7.4

Plugin Version

2.4.2

AMP plugin template mode

Standard

WordPress Version

6.4.0 (Nightly)

Site Health

No response

Gutenberg Version

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OS(s) Affected

No response

Browser(s) Affected

No response

Device(s) Affected

No response

Acceptance Criteria

No response

Implementation Brief

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QA Testing Instructions

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Demo

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Changelog Entry

No response

Yes, this is result of https://core.trac.wordpress.org/ticket/58775

We'll need to fix by the time WordPress 6.4 is released.

As for the fix, the code in question is:

amp-wp/includes/class-amp-theme-support.php

Lines 1228 to 1241 in 2c4df9e

    
           remove_action( 'wp_head', $header_callback ); 
        
           if ( '__return_false' !== $header_callback ) { 
        
           	ob_start(); 
        
           	$header_callback(); 
        
           	$style = ob_get_clean(); 
        
           	$data  = trim( preg_replace( '#<style[^>]*>(.*)</style>#is', '$1', $style ) ); // See wp_add_inline_style(). 
        
           	// Override AMP's position:relative on the body for the sake of the AMP viewer, which is not relevant an an Admin Bar context. 
        
           	if ( amp_is_dev_mode() ) { 
        
           		$data .= 'html:not(#_) > body { position:unset !important; }'; 
        
           	} 
        
           	wp_add_inline_style( 'admin-bar', $data ); 
        
           }

I believe it can be rewritten as follows, or something like it:

if ( ! function_exists( 'wp_enqueue_admin_bar_header_styles' ) ) {
    remove_action( 'wp_head', $header_callback );
}
 if ( '__return_false' !== $header_callback ) { 
 	if ( ! function_exists( 'wp_enqueue_admin_bar_header_styles' ) ) {
 		ob_start(); 
 		$header_callback(); 
 		$style = ob_get_clean(); 
 		$data  = trim( preg_replace( '#<style[^>]*>(.*)</style>#is', '$1', $style ) ); // See wp_add_inline_style(). 
 	} else {
 		$data = '';
 	}
  
 	// Override AMP's position:relative on the body for the sake of the AMP viewer, which is not relevant an an Admin Bar context. 
 	if ( amp_is_dev_mode() ) { 
 		$data .= 'html:not(#_) > body { position:unset !important; }'; 
 	} 
  
 	wp_add_inline_style( 'admin-bar', $data ); 
 }

cc @spacedmonkey

QA Passed ✅

Cross-verified the issue and the applied solution is functioning correctly. Now, the deprecation warning related to the _admin_bar_bump_cb is not visible.

Before	After

	remove_action( 'wp_head', $header_callback );
	if ( '__return_false' !== $header_callback ) {
	ob_start();
	$header_callback();
	$style = ob_get_clean();
	$data = trim( preg_replace( '#<style[^>]>(.)</style>#is', '$1', $style ) ); // See wp_add_inline_style().

	// Override AMP's position:relative on the body for the sake of the AMP viewer, which is not relevant an an Admin Bar context.
	if ( amp_is_dev_mode() ) {
	$data .= 'html:not(#_) > body { position:unset !important; }';
	}

	wp_add_inline_style( 'admin-bar', $data );
	}