[WOOCOMMERCE] Add Product Categories to the "Product" Breadcrumb

functions.php

<?php
// Add product categories to the "Product" breadcrumb in WooCommerce.
// Get breadcrumbs on product pages that read: Home > Shop > Product category > Product Name
/*
* CAUTION: if a product is in more than one category, only show the first found category.
*/
add_filter( 'woo_breadcrumbs_trail', 'woo_custom_breadcrumbs_trail_add_product_categories', 20 );
function woo_custom_breadcrumbs_trail_add_product_categories ( $trail ) {
	if ( ( get_post_type() == 'product' ) && is_singular() ) {
		global $post;
		$taxonomy = 'product_cat';
		$terms = get_the_terms( $post->ID, $taxonomy );
		$links = array();
		if ( $terms && ! is_wp_error( $terms ) ) {
			$count = 0;
			foreach ( $terms as $c ) {
				$count++;
				if ( $count > 1 ) { continue; }
				$parents = woo_get_term_parents( $c->term_id, $taxonomy, true, ', ', $c->name, array() );
				if ( $parents != '' && ! is_wp_error( $parents ) ) {
					$parents_arr = explode( ', ', $parents );
					foreach ( $parents_arr as $p ) {
						if ( $p != '' ) { $links[] = $p; }
					}
				}
			}
			// Add the trail back on to the end.
			$trail_end = get_the_title($post->ID);
			// Add the new links, and the original trail's end, back into the trail.
			array_splice( $trail, 2, count( $trail ) - 1, $links );
			$trail['trail_end'] = $trail_end;
		}
	}
	return $trail;
} // End woo_custom_breadcrumbs_trail_add_product_categories()