Fix fees

public/actions/submit.php

@@ -237,8 +237,9 @@ $database->action(function ($database) {
 
     // Add Stripe fees
     // https://support.stripe.com/questions/passing-the-stripe-fee-on-to-customers
-    if ($SETTINGS["prices"]["add_stripe_fees"]) {
+    if ($SETTINGS["prices"]["add_stripe_fees"] && $duecard > 0) {
         $duecard = number_format(($duecard + 0.30) / (1 - 0.029), 2) * 1.0;
+        $dueusd = max(0, $duecard + $campcoupons);
     }
 
     echo "\nCost $dueusd total: $duecard to Stripe, $campcoupons as coupons\n";

public/static/signup.js

@@ -120,7 +120,7 @@ function updateTotal() {
 
     var couponcharge = ($("input[name=campcoupons]").val() * 1.0);
     var cardcharge = Math.max(totalcharge - couponcharge, 0);
-    if (prices.add_stripe_fees) {
+    if (prices.add_stripe_fees && cardcharge > 0) {
         cardcharge = (cardcharge + 0.3) / (1 - 0.029);
     }