From fb9013c9b41c293f067afe89b940f4c2692e3ae8 Mon Sep 17 00:00:00 2001
From: Felix Arntz <felix-arntz@leaves-and-love.net>
Date: Wed, 5 Jul 2023 21:38:24 +0000
Subject: [PATCH] Media: Ensure that large images before the main query loop
 are counted towards lazy-loading threshold.

Following [55318], [55847], and [56142], certain images in the header of the page have received support for potentially receiving `fetchpriority="high"` and having the `loading="lazy"` attribute omitted. However, these images being present did not affect the "content media count" which counts the images towards a certain threshold so that the first ones are not lazy-loaded.

This changeset also increases that count for such header images if they are larger than a certain threshold. The threshold is used to avoid e.g. a header with lots of small images such as icon graphics to skew the lazy-loading behavior.

Props thekt12, spacedmonkey, flixos90.
Fixes #58635.

Built from https://develop.svn.wordpress.org/trunk@56143


git-svn-id: http://core.svn.wordpress.org/trunk@55655 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/media.php   | 15 +++++++++++++++
 wp-includes/version.php |  2 +-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/wp-includes/media.php b/wp-includes/media.php
index 0da68e3d43..11815e65fa 100644
--- a/wp-includes/media.php
+++ b/wp-includes/media.php
@@ -5588,6 +5588,15 @@ function wp_get_loading_optimization_attributes( $tag_name, $attr, $context ) {
 		}
 		return $loading_attributes;
 	};
+	// Closure to increase media count for images with certain minimum threshold, mostly used for header images.
+	$maybe_increase_content_media_count = static function() use ( $attr ) {
+		/** This filter is documented in wp-admin/includes/media.php */
+		$wp_min_priority_img_pixels = apply_filters( 'wp_min_priority_img_pixels', 50000 );
+		// Images with a certain minimum size in the header of the page are also counted towards the threshold.
+		if ( $wp_min_priority_img_pixels <= $attr['width'] * $attr['height'] ) {
+			wp_increase_content_media_count();
+		}
+	};
 
 	$loading_attrs = array();
 
@@ -5640,11 +5649,15 @@ function wp_get_loading_optimization_attributes( $tag_name, $attr, $context ) {
 	 */
 	$header_area = WP_TEMPLATE_PART_AREA_HEADER;
 	if ( "template_part_{$header_area}" === $context ) {
+		// Increase media count if there are images in header above a certian minimum size threshold.
+		$maybe_increase_content_media_count();
 		return $postprocess( $loading_attrs, true );
 	}
 
 	// The custom header image is always expected to be in the header.
 	if ( 'get_header_image_tag' === $context ) {
+		// Increase media count if there are images in header above a certian minimum size threshold.
+		$maybe_increase_content_media_count();
 		return $postprocess( $loading_attrs, true );
 	}
 
@@ -5671,6 +5684,8 @@ function wp_get_loading_optimization_attributes( $tag_name, $attr, $context ) {
 			 */
 			&& did_action( 'get_header' ) && ! did_action( 'get_footer' )
 		) {
+			// Increase media count if there are images in header above a certian minimum size threshold.
+			$maybe_increase_content_media_count();
 			return $postprocess( $loading_attrs, true );
 		}
 	}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 44d90d40dd..f3e115398c 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.3-beta3-56142';
+$wp_version = '6.3-beta3-56143';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.