[Done v1.3.9d] No numeric check for quantity update on shopping_cart page

[lat9]

v1.3.9b, fresh install.

When the quantity boxes are shown on the shopping cart (for quantity update), there is no numeric checking for the value typed into the box. Entering a non-numeric value, like 'a', and then pressing the Update icon results in the product being deleted from the cart.

[DrByte]

/includes/classes/shopping_cart.php
around line 1530 you'll see this section of code.
Add the new lines as shown:

  function actionUpdateProduct($goto, $parameters) {
    global $messageStack;

    for ($i=0, $n=sizeof($_POST['products_id']); $i<$n; $i++) {
      $adjust_max= 'false';
      if (!is_numeric($_POST['cart_quantity'][$i]) || $_POST['cart_quantity'][$i] < 0) {
        $messageStack->add_session('header', ERROR_CORRECTIONS_HEADING . ERROR_PRODUCT_QUANTITY_UNITS_SHOPPING_CART . zen_get_products_name($_POST['products_id'][$i]), 'error');
        continue;
      }