Check if the post's submission is an "edit" action and not a "add new post" action - WordPress

post.php

/**
 * Checks if the post's submission is an "edit"
 * 
 * Details provided in this answer on Stack Overflow
 * @link http://stackoverflow.com/questions/41110437/condition-only-when-the-post-is-complete-edited-not-added-or-trash/41110996#41110996
 *
 * @since 1.0.0
 *
 * @param int $post_id Post ID to evaluate
 *
 * @return bool
 */
function is_post_submission_an_edit_task( $post_id ) {
	if ( ! isset( $_POST['action'] ) ) {
		return false;
	}

	if ( 'editpost' != $_POST['action'] ) {
		return false;
	}

	if ( ! isset( $_POST['_wp_http_referer'] ) ) {
		return false;
	}

	$referer = '/wp-admin/post.php?post=' . $post_id . '&action=edit&message=';

	return $referer === substr( $_POST['_wp_http_referer'], 0, strlen( $referer ) );
}

add_action( 'post_updated', 'process_after_product_edited', 10, 3 );
/**
 * Process work when the product has been edited.
 *
 * @since 1.0.0
 *
 * @param int     $post_id      Post ID.
 * @param WP_Post $post_after   Post object following the update.
 * @param WP_Post $post_before  Post object before the update.
 */
function process_after_product_edited( $post_id, $post_after, $post_before ) {

	if ( ! is_post_being_updated( $post_id ) ) {
		return;
	}

	if ( $post_after->post_type != 'product' ) {
		return;
	}

	// now you can do your work

}