[FIX] purchase: correct previous forward-port.

Domain was apply on the wrong model.

addons/purchase/models/res_partner.py

@@ -29,12 +29,12 @@ class res_partner(models.Model):
     @api.multi
     def _compute_supplier_invoice_count(self):
         # retrieve all children partners and prefetch 'parent_id' on them
-        all_partners = self.search([('id', 'child_of', self.ids), ('type', 'in', ('in_invoice', 'in_refund')])
+        all_partners = self.search([('id', 'child_of', self.ids)])
         all_partners.read(['parent_id'])
 
         supplier_invoice_groups = self.env['account.invoice'].read_group(
             domain=[('partner_id', 'in', all_partners.ids),
-                    ('type', '=', 'in_invoice')],
+                    ('type', 'in', ('in_invoice', 'in_refund'))],
             fields=['partner_id'], groupby=['partner_id']
         )
         for group in supplier_invoice_groups: