<?php
add_filter( 'woocommerce_add_to_cart_sold_individually_found_in_cart', 'handsome_bearded_guy_maybe_redirect_to_cart' );
function handsome_bearded_guy_maybe_redirect_to_cart( $found_in_cart ) {
if ( $found_in_cart ) {
wp_safe_redirect( wc_get_page_permalink( 'cart' ) );
exit;
}...