Pass cart positions to fee_calculation_for_cart

src/pretix/base/payment.py

@@ -702,8 +702,9 @@ class FreeOrderProvider(BasePaymentProvider):
     def is_allowed(self, request: HttpRequest, total: Decimal=None) -> bool:
         from .services.cart import get_fees
 
+        cart = get_cart(request)
         total = get_cart_total(request)
-        total += sum([f.value for f in get_fees(self.event, request, total, None, None)])
+        total += sum([f.value for f in get_fees(self.event, request, total, None, None, cart)])
         return total == 0
 
     def order_change_allowed(self, order: Order) -> bool:

src/pretix/base/services/cart.py

@@ -958,12 +958,12 @@ def update_tax_rates(event: Event, cart_id: str, invoice_address: InvoiceAddress
     return totaldiff
 
 
-def get_fees(event, request, total, invoice_address, provider):
+def get_fees(event, request, total, invoice_address, provider, positions):
     from pretix.presale.views.cart import cart_session
 
     fees = []
     for recv, resp in fee_calculation_for_cart.send(sender=event, request=request, invoice_address=invoice_address,
-                                                    total=total):
+                                                    total=total, positions=positions):
         if resp:
             fees += resp
 

src/pretix/presale/checkoutflow.py

@@ -505,8 +505,10 @@ class PaymentStep(QuestionsViewMixin, CartMixin, TemplateFlowStep):
 
     @cached_property
     def _total_order_value(self):
+        cart = get_cart(self.request)
         total = get_cart_total(self.request)
-        total += sum([f.value for f in get_fees(self.request.event, self.request, total, self.invoice_address, None)])
+        total += sum([f.value for f in get_fees(self.request.event, self.request, total, self.invoice_address, None,
+                                                cart)])
         return Decimal(total)
 
     @cached_property

src/pretix/presale/signals.py

@@ -119,7 +119,7 @@ argument will contain the request object.
 """
 
 fee_calculation_for_cart = EventPluginSignal(
-    providing_args=['request', 'invoice_address', 'total']
+    providing_args=['request', 'invoice_address', 'total', 'positions']
 )
 """
 This signals allows you to add fees to a cart. You are expected to return a list of ``OrderFee``
@@ -129,6 +129,7 @@ As with all plugin signals, the ``sender`` keyword argument will contain the eve
 argument will contain the request object and ``invoice_address`` the invoice address (useful for
 tax calculation). The ``total`` keyword argument will contain the total cart sum without any fees.
 You should not rely on this ``total`` value for fee calculations as other fees might interfere.
+The ``positions`` argument will contain a list or queryset of ``CartPosition`` objects.
 """
 
 contact_form_fields = EventPluginSignal(

src/pretix/presale/views/__init__.py

@@ -133,7 +133,10 @@ class CartMixin:
         if order:
             fees = order.fees.all()
         elif positions:
-            fees = get_fees(self.request.event, self.request, total, self.invoice_address, self.cart_session.get('payment'))
+            fees = get_fees(
+                self.request.event, self.request, total, self.invoice_address, self.cart_session.get('payment'),
+                cartpos
+            )
         else:
             fees = []
 
@@ -231,9 +234,10 @@ def get_cart_is_free(request):
 
     if not hasattr(request, '_cart_free_cache'):
         cs = cart_session(request)
+        pos = get_cart(request)
         ia = get_cart_invoice_address(request)
         total = get_cart_total(request)
-        fees = get_fees(request.event, request, total, ia, cs.get('payment'))
+        fees = get_fees(request.event, request, total, ia, cs.get('payment'), pos)
         request._cart_free_cache = total + sum(f.value for f in fees) == Decimal('0.00')
     return request._cart_free_cache