Ensure comma not formatted into amount

Probably the function doesn't add anything as params['amount']
should be correctly formatted - however,
it shouldn't add a comma - per
eileenmcnaughton/nz.co.fuzion.omnipaymultiprocessor#227

CRM/Core/Payment.php

@@ -1155,20 +1155,20 @@ protected function getCurrency($params = []) {
   }
 
   /**
-   * Legacy. Better for a method to work on its own PropertyBag,
-   * but also, this function does not do very much.
+   * Get the submitted amount, padded to 2 decimal places, if needed.
    *
    * @param array $params
    *
    * @return string
-   * @throws \CRM_Core_Exception
    */
   protected function getAmount($params = []) {
     if (!CRM_Utils_Rule::numeric($params['amount'])) {
       CRM_Core_Error::deprecatedWarning('Passing Amount value that is not numeric is deprecated please report this in gitlab');
       return CRM_Utils_Money::formatUSLocaleNumericRounded(filter_var($params['amount'], FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION), 2);
     }
-    return CRM_Utils_Money::formatUSLocaleNumericRounded($params['amount'], 2);
+    // Amount is already formatted to a machine-friendly format but may NOT have
+    // decimal places - eg. it could be 1000.1 so this would return 1000.10.
+    return Civi::format()->moneyNumber($params['amount'], 'USD', 'en_US');
   }
 
   /**

Civi/Core/Format.php

@@ -93,8 +93,26 @@ public function moneyNumber($amount, string $currency, $locale): string {
       return '';
     }
     $formatter = $this->getMoneyFormatter($currency, $locale, NumberFormatter::DECIMAL);
-    $money = Money::of($amount, $currency, NULL, RoundingMode::HALF_UP);
-    return $money->formatWith($formatter);
+    return Money::of($amount, $currency, NULL, RoundingMode::HALF_UP)->formatWith($formatter);
+  }
+
+  /**
+   * Get a number formatted to a machine format with decimal placed padded by currency.
+   *
+   * Most currencies format to 2 decimal places so the default of 'USD' will
+   * achieve that.
+   *
+   * For example an input of 1000.1 will return 1000.10.
+   *
+   * This will ensure that
+   *
+   * @param string|float|int $amount
+   * @param string $currency
+   *
+   * @return string
+   */
+  public function machineNumber($amount, string $currency = 'USD'): string {
+    return Civi::format()->moneyNumber($amount, $currency, 'en_US');
   }
 
   /**