Quantize to number of digits instead of rounding computed amount

Rounding may change the result if currency rounding is not unitary.

issue7284
review37251002

account.py

@@ -263,7 +263,8 @@ class Type(sequence_ordered(), ModelSQL, ModelView):
                     ])
             for child in childs:
                 res[type_.id] += type_sum[child.id]
-            res[type_.id] = type_.company.currency.round(res[type_.id])
+            exp = Decimal(str(10.0 ** -type_.currency_digits))
+            res[type_.id] = res[type_.id].quantize(exp)
             if type_.display_balance == 'credit-debit':
                 res[type_.id] = - res[type_.id]
         return res
@@ -809,7 +810,7 @@ class Account(DeactivableMixin, ModelSQL, ModelView):
         table_c = cls.__table__()
         line = MoveLine.__table__()
         ids = [a.id for a in accounts]
-        balances = dict((i, 0) for i in ids)
+        balances = dict((i, Decimal(0)) for i in ids)
         line_query, fiscalyear_ids = MoveLine.query_get(line)
         for sub_ids in grouped_slice(ids):
             red_sql = reduce_ids(table_a.id, sub_ids)
@@ -832,8 +833,8 @@ class Account(DeactivableMixin, ModelSQL, ModelView):
             balances[account_id] = Decimal(str(balance))
 
         for account in accounts:
-            balances[account.id] = account.company.currency.round(
-                balances[account.id])
+            exp = Decimal(str(10.0 ** -account.currency_digits))
+            balances[account.id] = balances[account.id].quantize(exp)
 
         fiscalyears = FiscalYear.browse(fiscalyear_ids)
 
@@ -859,7 +860,7 @@ class Account(DeactivableMixin, ModelSQL, ModelView):
         for name in names:
             if name not in {'credit', 'debit', 'amount_second_currency'}:
                 raise ValueError('Unknown name: %s' % name)
-            result[name] = dict((i, 0) for i in ids)
+            result[name] = dict((i, Decimal(0)) for i in ids)
 
         table = cls.__table__()
         line = MoveLine.__table__()
@@ -885,12 +886,11 @@ class Account(DeactivableMixin, ModelSQL, ModelView):
         for account in accounts:
             for name in names:
                 if name == 'amount_second_currency':
-                    currency = account.second_currency
+                    exp = Decimal(str(10.0 ** -account.second_currency_digits))
                 else:
-                    currency = account.company.currency
-                if currency:
-                    result[name][account.id] = currency.round(
-                        result[name][account.id])
+                    exp = Decimal(str(10.0 ** -account.currency_digits))
+                result[name][account.id] = (
+                    result[name][account.id].quantize(exp))
 
         cumulate_names = []
         if Transaction().context.get('cumulate'):

move.py

@@ -1203,7 +1203,6 @@ class Line(ModelSQL, ModelView):
                     reconcile_account = line.account
                 if not reconcile_party:
                     reconcile_party = line.party
-            amount = reconcile_account.currency.round(amount)
             if amount:
                 move = cls._get_writeoff_move(
                     reconcile_account, reconcile_party, amount, **writeoff)

party.py

@@ -136,7 +136,7 @@ class Party(CompanyMultiValueMixin):
         if not user.company:
             return result
         company_id = user.company.id
-        to_round = False
+        exp = Decimal(str(10.0 ** -user.company.currency.digits))
 
         amount = Sum(Coalesce(line.debit, 0) - Coalesce(line.credit, 0))
         for name in names:
@@ -163,14 +163,7 @@ class Party(CompanyMultiValueMixin):
                     # SQLite uses float for SUM
                     if not isinstance(value, Decimal):
                         value = Decimal(str(value))
-                        to_round = True
-                    result[name][party] = value
-        # Float amount must be rounded to get the right precision
-        if to_round:
-            currency = user.company.currency
-            for name, values in result.iteritems():
-                for id, value in values.iteritems():
-                    values[id] = currency.round(value)
+                    result[name][party] = value.quantize(exp)
         return result
 
     @classmethod

tax.py

@@ -201,8 +201,9 @@ class TaxCode(DeactivableMixin, ModelSQL, ModelView):
                 ('parent', 'child_of', [c.id for c in codes]),
                 ])
         for code in childs:
-            result[code.id] = code.company.currency.round(
-                sum((l.value for l in code.lines), Decimal(0)))
+            exp = Decimal(str(10.0 ** -code.currency_digits))
+            result[code.id] = sum(
+                (l.value for l in code.lines), Decimal(0)).quantize(exp)
             parents[code.id] = code.parent.id if code.parent else None
 
         ids = set(map(int, childs))

tests/scenario_account_reconciliation.rst

@@ -151,4 +151,4 @@ Reconcile Lines with writeoff::
     >>> writeoff_line2.account == expense
     True
     >>> writeoff_line2.debit
-    Decimal('3.00')
+    Decimal('3.0')