diff -r be944660c56a -r 3d72ae0968f4 wp/wp-includes/blocks/site-logo.php
--- a/wp/wp-includes/blocks/site-logo.php	Wed Sep 21 18:19:35 2022 +0200
+++ b/wp/wp-includes/blocks/site-logo.php	Tue Sep 27 16:37:53 2022 +0200
@@ -14,7 +14,7 @@
  */
 function render_block_core_site_logo( $attributes ) {
 	$adjust_width_height_filter = function ( $image ) use ( $attributes ) {
-		if ( empty( $attributes['width'] ) || empty( $image ) ) {
+		if ( empty( $attributes['width'] ) || empty( $image ) || ! $image[1] || ! $image[2] ) {
 			return $image;
 		}
 		$height = (float) $attributes['width'] / ( (float) $image[1] / (float) $image[2] );
@@ -40,18 +40,10 @@
 		// Add the link target after the rel="home".
 		// Add an aria-label for informing that the page opens in a new tab.
 		$aria_label  = 'aria-label="' . esc_attr__( '(Home link, opens in a new tab)' ) . '"';
-		$custom_logo = str_replace( 'rel="home"', 'rel="home" target="' . $attributes['linkTarget'] . '"' . $aria_label, $custom_logo );
+		$custom_logo = str_replace( 'rel="home"', 'rel="home" target="' . esc_attr( $attributes['linkTarget'] ) . '"' . $aria_label, $custom_logo );
 	}
 
 	$classnames = array();
-	if ( ! empty( $attributes['className'] ) ) {
-		$classnames[] = $attributes['className'];
-	}
-
-	if ( ! empty( $attributes['align'] ) && in_array( $attributes['align'], array( 'center', 'left', 'right' ), true ) ) {
-		$classnames[] = "align{$attributes['align']}";
-	}
-
 	if ( empty( $attributes['width'] ) ) {
 		$classnames[] = 'is-default-size';
 	}
@@ -81,6 +73,23 @@
 add_action( 'rest_api_init', 'register_block_core_site_logo_setting', 10 );
 
 /**
+ * Register a core site setting for a site icon
+ */
+function register_block_core_site_icon_setting() {
+	register_setting(
+		'general',
+		'site_icon',
+		array(
+			'show_in_rest' => true,
+			'type'         => 'integer',
+			'description'  => __( 'Site icon.' ),
+		)
+	);
+}
+
+add_action( 'rest_api_init', 'register_block_core_site_icon_setting', 10 );
+
+/**
  * Registers the `core/site-logo` block on the server.
  */
 function register_block_core_site_logo() {
@@ -133,6 +142,12 @@
  * @param array $value     Updated theme mod settings.
  */
 function _delete_site_logo_on_remove_custom_logo( $old_value, $value ) {
+	global $_ignore_site_logo_changes;
+
+	if ( $_ignore_site_logo_changes ) {
+		return;
+	}
+
 	// If the custom_logo is being unset, it's being removed from theme mods.
 	if ( isset( $old_value['custom_logo'] ) && ! isset( $value['custom_logo'] ) ) {
 		delete_option( 'site_logo' );
@@ -143,6 +158,12 @@
  * Deletes the site logo when all theme mods are being removed.
  */
 function _delete_site_logo_on_remove_theme_mods() {
+	global $_ignore_site_logo_changes;
+
+	if ( $_ignore_site_logo_changes ) {
+		return;
+	}
+
 	if ( false !== get_theme_support( 'custom-logo' ) ) {
 		delete_option( 'site_logo' );
 	}
@@ -160,3 +181,21 @@
 	add_action( "delete_option_theme_mods_$theme", '_delete_site_logo_on_remove_theme_mods' );
 }
 add_action( 'setup_theme', '_delete_site_logo_on_remove_custom_logo_on_setup_theme', 11 );
+
+/**
+ * Removes the custom_logo theme-mod when the site_logo option gets deleted.
+ */
+function _delete_custom_logo_on_remove_site_logo() {
+	global $_ignore_site_logo_changes;
+
+	// Prevent _delete_site_logo_on_remove_custom_logo and
+	// _delete_site_logo_on_remove_theme_mods from firing and causing an
+	// infinite loop.
+	$_ignore_site_logo_changes = true;
+
+	// Remove the custom logo.
+	remove_theme_mod( 'custom_logo' );
+
+	$_ignore_site_logo_changes = false;
+}
+add_action( 'delete_option_site_logo', '_delete_custom_logo_on_remove_site_logo' );