old_contents: # -*- coding: utf-8 -*-
  # © 2016 Carlos Dauden <carlos.dauden@tecnativa.com>
  # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
  
  from openerp import api, models
  
  
  class PurchaseOrderLine(models.Model):
      _inherit = 'account.analytic.account'
  
      @api.multi
      def _recurring_create_invoice(self, automatic=False):
          invoice_obj = self.env['account.invoice']
          invoices = invoice_obj.browse(
              super(PurchaseOrderLine, self)._recurring_create_invoice(automatic))
          res = []
          unlink_list = []
          for partner in invoices.mapped('partner_id'):
              inv_to_merge = invoices.filtered(
                  lambda x: x.partner_id.id == partner)
              if partner.contract_invoice_merge:
                  invoices_merged = inv_to_merge.do_merge()
                  res.extend(invoices_merged)
                  unlink_list.extend(inv_to_merge)
              else:
                  res.extend(inv_to_merge)
          if unlink_list:
              invoice_obj.unlink([x.id for x in unlink_list])
          return res
  
new_contents: # -*- coding: utf-8 -*-
  # © 2016 Carlos Dauden <carlos.dauden@tecnativa.com>
  # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
  
  from openerp import api, models
  
  
  class PurchaseOrderLine(models.Model):
      _inherit = 'account.analytic.account'
  
      @api.multi
      def _recurring_create_invoice(self, automatic=False):
          invoice_obj = self.env['account.invoice']
          invoices = invoice_obj.browse(
              super(PurchaseOrderLine, self)._recurring_create_invoice(
                  automatic))
          res = []
          unlink_list = []
          for partner in invoices.mapped('partner_id'):
              inv_to_merge = invoices.filtered(
                  lambda x: x.partner_id.id == partner)
              if partner.contract_invoice_merge and len(inv_to_merge) > 1:
                  invoices_merged = inv_to_merge.do_merge()
                  res.extend(invoices_merged)
                  unlink_list.extend(inv_to_merge)
              else:
                  res.extend(inv_to_merge)
          if unlink_list:
              invoice_obj.browse(unlink_list).unlink()
          return res
  
subject: Fix unlink, >1 filter and lines too long