PayPal deleting the comma from PayPal Standard in Jan 2017

IMPORTANT NOTE for stores using PayPal Standard with Zen Cart:

1. FIRST: Note that PayPal Express Checkout is a much better experience for your customers, and more reliable for your store.
The better solution to the issue presented here is to simply switch to using Express Checkout instead of PayPal Standard.


2. Starting January 18, 2017 PayPal Standard will not be able to accept transactions with a purchase amount which includes a "comma" symbol.
(ie: a comma such as a "thousands separator" in an amount such as $1,234.56)


WHAT THIS MEANS FOR YOU:
a) You should switch to Express Checkout instead. Simple. Done.


b) If you "need" to use PayPal Payments Standard for some rare reason, you will need to make the following code changes yourself:

Change "number_format(" to "round(" on the following lines of the files found in /includes/modules/payment:

Version 1.3.9:
- paypal.php line 261
- paypal/paypal_functions.php lines 951, 957, 962

Version 1.5.0:
- paypal.php line 261
- paypal/paypal_functions.php lines 960, 966, 971

Version 1.5.1:
- paypal.php line 262
- paypal/paypal_functions.php lines 960, 966, 971

Versions 1.5.2, 1.5.3, 1.5.4:
- paypal.php line 270
- paypal/paypal_functions.php lines 960, 966, 971

Version 1.5.5:
- paypal.php line 270
- paypal/paypal_functions.php lines 966, 972, 977


c) If the above sounds painful, you should switch to Express Checkout instead. Simple. Done.