Ticket #53319: category-template.php

<?php
/**
 * Retrieves term parents with separator.
 *
 * @since 4.8.0
 *
 * @param int          $term_id  Term ID.
 * @param string       $taxonomy Taxonomy name.
 * @param string|array $args {
 *     Array of optional arguments.
 *
 *     @type string $format    Use term names or slugs for display. Accepts 'name' or 'slug'.
 *                             Default 'name'.
 *     @type string $separator Separator for between the terms. Default '/'.
 *     @type bool   $link      Whether to format as a link. Default true.
 *     @type bool   $inclusive Include the term to get the parents for. Default true.
 *     @type bool   $inverse   Wether to reverse the hierarchical order of the Terms on output. Default true.
 * }
 * @return string|WP_Error A list of term parents on success, WP_Error or empty string on failure.
 */
function get_term_parents_list( $term_id, $taxonomy, $args = array() ) {
    $list = '';
    $term = get_term( $term_id, $taxonomy );
 
    if ( is_wp_error( $term ) ) {
        return $term;
    }
 
    if ( ! $term ) {
        return $list;
    }
 
    $term_id = $term->term_id;
 
    $defaults = array(
        'format'    => 'name',
        'separator' => '/',
        'link'      => true,
        'inclusive' => true,
        'inverse'   => true,
    );
 
    $args = wp_parse_args( $args, $defaults );
 
    foreach ( array( 'link', 'inclusive' ) as $bool ) {
        $args[ $bool ] = wp_validate_boolean( $args[ $bool ] );
    }
 
    $parents = get_ancestors( $term_id, $taxonomy, 'taxonomy' );
 
    if ( $args['inclusive'] ) {
        array_unshift( $parents, $term_id );
    }
        
        /**
         * @since 5.7.3
         */
        if( $args['inverse'] ){
                $parents = array_reverse( $parents );
        }

    foreach ( $parents as $term_id ) {
        $parent = get_term( $term_id, $taxonomy );
        $name   = ( 'slug' === $args['format'] ) ? $parent->slug : $parent->name;
 
        if ( $args['link'] ) {
            $list .= '<a href="' . esc_url( get_term_link( $parent->term_id, $taxonomy ) ) . '">' . $name . '</a>' . $args['separator'];
        } else {
            $list .= $name . $args['separator'];
        }
    }
 
    return $list;
}