fatal error due to bug

The current code in decimal-product-quantity-for-woocommerce.php is:

? ? ? ? add_filter?(‘woocommerce_quantity_input_args’,?‘WooDecimalProduct_filter_quantity_input_args’,?999999,?2); function?WooDecimalProduct_filter_quantity_input_args($args,?$product)?{

if?(product)?{

This is generating a fatal error in some circumstances due to a missing $ on line 47. It should be $product