Sort posted lines to reconcile at last by party

The lines may or may not have a party depending on the account.
So the order key must avoid compare party instance with None value.

Closes #13268
(grafted from 97e730164485c038de7744ea0a3fb189fd7426fa)

--HG--
branch : 7.0

modules/account/move.py

@@ -504,7 +504,9 @@ class Move(DescriptionOriginMixin, ModelSQL, ModelView):
         cls.save(moves)
 
         def keyfunc(line):
-            return line.party, line.account
+            # Set party last to avoid compare party instance and None
+            # party will always be None for the same account
+            return line.account, line.party
         to_reconcile = Line.browse(sorted(
                 [l for l in Line.browse(to_reconcile) if l.account.reconcile],
                 key=keyfunc))

modules/account/tests/test_module.py

@@ -656,12 +656,15 @@ class AccountTestCase(
             self.assertEqual(move.state, 'posted')
 
             # Move lines with debit = credit = 0 are automatically reconciled
+            receivable_no_party, = Account.copy([receivable], default={
+                    'party_required': False,
+                    })
             move = Move()
             move.period = period
             move.journal = journal_revenue
             move.date = period.start_date
             move.lines = [
-                Line(account=revenue, credit=Decimal(0)),
+                Line(account=receivable_no_party, credit=Decimal(0)),
                 Line(account=receivable, debit=Decimal(0), party=party),
                 ]
             move.save()