[FIX] account: set inv state to 'open' when unreconciling in 'in_payment'

- Check post_at_bank_rec on bank journal.
- Create an invoice of amount=x
- Register a payment of amount=x using the bank journal
(invoice state is now 'in_payment')
- unreconcile the payment

... The invoice state is still 'in_payment' instead of going back to 'open'.

addons/account/models/account_invoice.py

@@ -528,7 +528,7 @@ class AccountInvoice(models.Model):
         reconciled = self.filtered(lambda invoice: invoice.reconciled)
         not_reconciled = self - reconciled
         (reconciled & pre_reconciled).filtered(lambda invoice: invoice.state == 'open').action_invoice_paid()
-        (not_reconciled & pre_not_reconciled).filtered(lambda invoice: invoice.state == 'paid').action_invoice_re_open()
+        (not_reconciled & pre_not_reconciled).filtered(lambda invoice: invoice.state in ('in_payment', 'paid')).action_invoice_re_open()
         return res
 
     @api.model
@@ -916,7 +916,7 @@ class AccountInvoice(models.Model):
 
     @api.multi
     def action_invoice_re_open(self):
-        if self.filtered(lambda inv: inv.state != 'paid'):
+        if self.filtered(lambda inv: inv.state not in ('in_payment', 'paid')):
             raise UserError(_('Invoice must be paid in order to set it to register payment.'))
         return self.write({'state': 'open'})