From 4e58ba759409a84352f2ee45d090aabe2bcadf77 Mon Sep 17 00:00:00 2001
From: Raphael Michel <mail@raphaelmichel.de>
Date: Mon, 30 Sep 2019 14:35:22 +0200
Subject: [PATCH] money_filter: Idempotency on empty strings

PRETIXEU-1EH
---
 src/pretix/base/templatetags/money.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/pretix/base/templatetags/money.py b/src/pretix/base/templatetags/money.py
index a7f5800a9d..75e5adac33 100644
--- a/src/pretix/base/templatetags/money.py
+++ b/src/pretix/base/templatetags/money.py
@@ -14,6 +14,8 @@ def money_filter(value: Decimal, arg='', hide_currency=False):
     if isinstance(value, float) or isinstance(value, int):
         value = Decimal(value)
     if not isinstance(value, Decimal):
+        if value == '':
+            return value
         raise TypeError("Invalid data type passed to money filter: %r" % type(value))
     if not arg:
         raise ValueError("No currency passed.")