How is meta information saved in WPSC metabox?

Question

I am adding some specific functions to WPeCommerce Plugin and faced a problem with saving information in metaboxes in edit post page. What I noticed is that the meta info is being saved directly without calling a function update_option(); The input name is kinda this type: "meta[_wpsc_sku]", so basically I added my new metaboxes with the same type: "meta[_custom_meta_key]". The problem is when I delete with jQuery this input field in metabox, the meta key/value in database is not deleted. So, how do I take over control over this stuff? How do I sanitize values and delete them if no $_POST[meta[_custom_meta_key]] is passed? Thanks

Answer 1

Ok, I found the solution. The function which was saving such meta information is located in file /wpsc-admin/includes/product-functions.php on line 41 and called wpsc_admin_submit_product.