onAfterCartUpdate infinite loop

public function onAfterCartUpdate(&$cartClass,&$cart,$product_id,$quantity,$add,$type,$resetCartWhenUpdate,$force){ //die(print_r($product_id)); //if( $product_id != '17962' ){ Does not work because $product_id is an Array, and the id is either the "real" product id, or the id from the table "hikashop_cart_product", which I do not know $c = $cartClass->loadFullCart(); if( count($c->products) ){ $sum = 0; foreach($c->products as $i => $product){ if( !empty($product->length) ){ // if product has custom field "length" $sum += $product->cart_product_quantity - 1; // that "- 1" is willed... } } $cartClass->update('17962', $sum); // infinite loop } //} }