wp-admin/includes/class-wp-site-icon.php:209Deletes the Site Icon when the image file is deleted.
$post_idint public function delete_attachment_data( $post_id ) { $site_icon_id = (int) get_option( 'site_icon' ); if ( $site_icon_id && $post_id === $site_icon_id ) { delete_option( 'site_icon' ); } }Introduced in 4.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/class-wp-site-icon.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.