From b317b8714779c00973aab8f7db5214bc650d84a9 Mon Sep 17 00:00:00 2001
From: audrasjb <audrasjb@git.wordpress.org>
Date: Thu, 7 Apr 2022 22:14:05 +0000
Subject: [PATCH] Toolbar: Add a filter to help remove site icons from toolbar
 for large multisite, and lazy load them by default.

This changeset introduces the `wp_admin_bar_show_site_icons` filter to help developers to hide site icons from the toolbar, as it may have negative performance impact on large multisites. It also adds a default lazy load behavior for these icons.

Props wslyhbb, sabernhardt, lkraav, kebbet, peterwilsoncc.
Fixes #54447

Built from https://develop.svn.wordpress.org/trunk@53100


git-svn-id: http://core.svn.wordpress.org/trunk@52689 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/admin-bar.php | 19 ++++++++++++++++---
 wp-includes/version.php   |  2 +-
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/wp-includes/admin-bar.php b/wp-includes/admin-bar.php
index 6f05fb7b26..274212acf7 100644
--- a/wp-includes/admin-bar.php
+++ b/wp-includes/admin-bar.php
@@ -611,14 +611,27 @@ function wp_admin_bar_my_sites_menu( $wp_admin_bar ) {
 		)
 	);
 
+	/**
+	 * Filters whether to show the site icons in toolbar.
+	 *
+	 * Returning false to this hook is the recommended way to hide site icons in the toolbar.
+	 * A truthy return may have negative performance impact on large multisites.
+	 *
+	 * @since 6.0.0
+	 *
+	 * @param bool $show_site_icons Whether site icons should be shown in the toolbar. Default true.
+	 */
+	$show_site_icons = apply_filters( 'wp_admin_bar_show_site_icons', true );
+
 	foreach ( (array) $wp_admin_bar->user->blogs as $blog ) {
 		switch_to_blog( $blog->userblog_id );
 
-		if ( has_site_icon() ) {
+		if ( true === $show_site_icons && has_site_icon() ) {
 			$blavatar = sprintf(
-				'<img class="blavatar" src="%s" srcset="%s 2x" alt="" width="16" height="16" />',
+				'<img class="blavatar" src="%s" srcset="%s 2x" alt="" width="16" height="16"%s />',
 				esc_url( get_site_icon_url( 16 ) ),
-				esc_url( get_site_icon_url( 32 ) )
+				esc_url( get_site_icon_url( 32 ) ),
+				( wp_lazy_loading_enabled( 'img', 'site_icon_in_toolbar' ) ? ' loading="lazy"' : '' )
 			);
 		} else {
 			$blavatar = '<div class="blavatar"></div>';
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 4b03bb10e5..e4058e8822 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-53099';
+$wp_version = '6.0-alpha-53100';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.