Add round_price

We add a common method to round prices that are stored using the price digits.
It is useless to use the digits from the field because it can not be changed in
any other way than by configuration.

issue9146
review299521002

sale.py

@@ -1,7 +1,5 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
-from decimal import Decimal
-
 from trytond import backend
 from trytond.i18n import gettext
 from trytond.model import ModelView, Workflow, fields
@@ -9,7 +7,7 @@ from trytond.transaction import Transaction
 from trytond.pyson import Eval, If
 from trytond.pool import Pool, PoolMeta
 
-from trytond.modules.product import price_digits
+from trytond.modules.product import price_digits, round_price
 from trytond.modules.sale.exceptions import SaleConfirmError
 
 sale_shipment_cost_method = fields.Selection(
@@ -242,8 +240,7 @@ class Sale(metaclass=PoolMeta):
             if last_line.sequence is not None:
                 sequence = last_line.sequence + 1
 
-        shipment_cost = cost.quantize(
-            Decimal(1) / 10 ** SaleLine.shipment_cost.digits[1])
+        shipment_cost = round_price(cost)
         cost_line = SaleLine(
             sale=self,
             sequence=sequence,
@@ -254,8 +251,7 @@ class Sale(metaclass=PoolMeta):
             shipment_cost=shipment_cost,
             )
         cost_line.on_change_product()
-        cost_line.unit_price = cost.quantize(
-            Decimal(1) / 10 ** SaleLine.unit_price.digits[1])
+        cost_line.unit_price = round_price(cost)
         cost_line.amount = cost_line.on_change_with_amount()
         return cost_line
 
@@ -269,8 +265,7 @@ class Sale(metaclass=PoolMeta):
                 with Transaction().set_context(
                         shipment.get_carrier_context()):
                     cost, currency_id = self.carrier.get_sale_price()
-                cost = cost.quantize(
-                    Decimal(1) / 10 ** Shipment.cost.digits[1])
+                cost = round_price(cost)
                 Shipment.write([shipment], {
                         'carrier': self.carrier.id,
                         'cost': cost,

stock.py

@@ -1,14 +1,12 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
-from decimal import Decimal
-
 from trytond.i18n import gettext
 from trytond.model import fields
 from trytond.pyson import Eval, Bool
 from trytond.transaction import Transaction
 from trytond.pool import Pool, PoolMeta
 
-from trytond.modules.product import price_digits
+from trytond.modules.product import price_digits, round_price
 from .exceptions import InvoiceShipmentCostError
 
 
@@ -56,8 +54,7 @@ class ShipmentOut(metaclass=PoolMeta):
             return
         with Transaction().set_context(self._get_carrier_context()):
             cost, currency_id = self.carrier.get_sale_price()
-        self.cost = cost.quantize(
-            Decimal(1) / 10 ** self.__class__.cost.digits[1])
+        self.cost = round_price(cost)
         self.cost_currency = currency_id
 
     def _get_cost_tax_rule_pattern(self):
@@ -91,8 +88,7 @@ class ShipmentOut(metaclass=PoolMeta):
             with Transaction().set_context(date=invoice.currency_date):
                 cost = Currency.compute(self.cost_currency, cost,
                     invoice.currency, round=False)
-        invoice_line.unit_price = cost.quantize(
-            Decimal(1) / 10 ** InvoiceLine.unit_price.digits[1])
+        invoice_line.unit_price = round_price(cost)
 
         taxes = []
         pattern = self._get_cost_tax_rule_pattern()

tryton.cfg

@@ -5,6 +5,7 @@ depends:
     carrier
     currency
     ir
+    product
     res
     sale
     stock