woocommerce/includes/class-wc-post-data.php

<?php

if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly

/**
 * Post Data
 *
 * Standardises certain post data on save.
 *
 * @class 		WC_Post_Data
 * @version		2.1.0
 * @package		WooCommerce/Classes/Data
 * @category	Class
 * @author 		WooThemes
 */
class WC_Post_Data {

	/**
	 * Constructor
	 */
	public function __construct() {
		add_filter( 'update_order_item_metadata', array( $this, 'update_order_item_metadata' ), 10, 5 );
		add_filter( 'update_post_metadata', array( $this, 'update_post_metadata' ), 10, 5 );
	}

	/**
	 * Ensure floats are correctly converted to strings based on PHP locale
	 * 
	 * @param  null $check
	 * @param  int $object_id
	 * @param  string $meta_key
	 * @param  mixed $meta_value
	 * @param  mixed $prev_value
	 * @return null|bool
	 */
	public function update_order_item_metadata( $check, $object_id, $meta_key, $meta_value, $prev_value ) {
		if ( ! empty( $meta_value ) && is_float( $meta_value ) ) {

			// Convert float to string
			$meta_value = wc_float_to_string( $meta_value );

			// Update meta value with new string
			update_metadata( 'order_item', $object_id, $meta_key, $meta_value, $prev_value );

			// Return
			return true;
		}
		return $check;
	}

	/**
	 * Ensure floats are correctly converted to strings based on PHP locale
	 * 
	 * @param  null $check
	 * @param  int $object_id
	 * @param  string $meta_key
	 * @param  mixed $meta_value
	 * @param  mixed $prev_value
	 * @return null|bool
	 */
	public function update_post_metadata( $check, $object_id, $meta_key, $meta_value, $prev_value ) {
		if ( ! empty( $meta_value ) && is_float( $meta_value ) && in_array( get_post_type( $object_id ), array( 'shop_order', 'shop_coupon', 'product', 'product_variation' ) ) ) {

			// Convert float to string
			$meta_value = wc_float_to_string( $meta_value );

			// Update meta value with new string
			update_metadata( 'post', $object_id, $meta_key, $meta_value, $prev_value );

			// Return
			return true;
		}
		return $check;
	}

}

new WC_Post_Data();