Remove positivity constraint in apply_voucher

src/pretix/base/services/cart.py

@@ -461,8 +461,10 @@ class CartManager:
                         bundled_sum += bundledprice
 
             price = self._get_price(p.item, p.variation, voucher, None, p.subevent, bundled_sum=bundled_sum)
+            """
             if price.gross > p.price:
                 continue
+            """
 
             voucher_use_diff[voucher] += 1
             ops.append((p.price - price.gross, self.VoucherOperation(p, voucher, price)))

src/tests/presale/test_cart.py

@@ -1827,6 +1827,7 @@ class CartTest(CartTestMixin, TestCase):
             assert cp2.voucher == v2
             assert cp2.price == Decimal('150.00')
 
+    """
     def test_voucher_apply_only_positive(self):
         with scopes_disabled():
             cp1 = CartPosition.objects.create(
@@ -1849,6 +1850,7 @@ class CartTest(CartTestMixin, TestCase):
             cp2.refresh_from_db()
             assert cp1.voucher is None
             assert cp2.voucher is None
+    """
 
     def test_voucher_apply_expired(self):
         with scopes_disabled():