From 0a42b53b2d7522f620deefcd4dfe1fe5d5a32bdf Mon Sep 17 00:00:00 2001
From: andig <andi@evcc.io>
Date: Sun, 23 Jun 2024 17:05:54 +0200
Subject: [PATCH] Tariffs: add tax only on positive prices (#14527)

---
 tariff/embed.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tariff/embed.go b/tariff/embed.go
index 5b171e220..9072a19c8 100644
--- a/tariff/embed.go
+++ b/tariff/embed.go
@@ -6,5 +6,9 @@ type embed struct {
 }
 
 func (t *embed) totalPrice(price float64) float64 {
-	return (price + t.Charges) * (1 + t.Tax)
+	total := price + t.Charges
+	if total > 0 {
+		total *= 1 + t.Tax
+	}
+	return total
 }