Allow cash rounding with opposite method

modules/account_cash_rounding/CHANGELOG

@@ -1,3 +1,4 @@
+* Allow cash rounding with opposite method
 * Add support for Python 3.14
 * Remove support for Python 3.9
 

modules/account_cash_rounding/currency.py

@@ -3,6 +3,7 @@
 from decimal import ROUND_HALF_EVEN
 
 from trytond.model import fields
+from trytond.modules.currency import ROUNDING_OPPOSITES
 from trytond.pool import PoolMeta
 from trytond.pyson import Eval
 
@@ -14,7 +15,9 @@ class Currency(metaclass=PoolMeta):
         "Cash Rounding Factor",
         digits=(None, Eval('digits', None)))
 
-    def cash_round(self, amount, rounding=ROUND_HALF_EVEN):
+    def cash_round(self, amount, rounding=ROUND_HALF_EVEN, opposite=False):
+        if opposite:
+            rounding = ROUNDING_OPPOSITES[rounding]
         if self.cash_rounding is not None:
             factor = self.cash_rounding
         else:

modules/currency/__init__.py

@@ -1,2 +1,11 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
+
+__all__ = ['ROUNDING_OPPOSITES']
+
+
+def __getattr__(name):
+    if name == 'ROUNDING_OPPOSITES':
+        from .currency import ROUNDING_OPPOSITES
+        return ROUNDING_OPPOSITES
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")