diff --git a/addons/purchase/models/purchase.py b/addons/purchase/models/purchase.py
index d1ca9683..04f99fe1 100644
--- a/addons/purchase/models/purchase.py
+++ b/addons/purchase/models/purchase.py
@@ -508,7 +508,7 @@ class PurchaseOrder(models.Model):
         result['context'] = {}
         pick_ids = self.mapped('picking_ids')
         #choose the view_mode accordingly
-        if len(pick_ids) > 1:
+        if not pick_ids or len(pick_ids) > 1:
             result['domain'] = "[('id','in',%s)]" % (pick_ids.ids)
         elif len(pick_ids) == 1:
             res = self.env.ref('stock.view_picking_form', False)
diff --git a/addons/purchase/models/stock.py b/addons/purchase/models/stock.py
index 33df8d2d..fd884df4 100644
--- a/addons/purchase/models/stock.py
+++ b/addons/purchase/models/stock.py
@@ -11,17 +11,6 @@ class StockPicking(models.Model):
     purchase_id = fields.Many2one('purchase.order', related='move_lines.purchase_line_id.order_id',
         string="Purchase Orders", readonly=True)
 
-    @api.model
-    def _create_backorder(self, backorder_moves=[]):
-        res = super(StockPicking, self)._create_backorder(backorder_moves)
-        for picking in self:
-            if picking.picking_type_id.code == 'incoming':
-                for backorder in self.search([('backorder_id', '=', picking.id)]):
-                    backorder.message_post_with_view('mail.message_origin_link',
-                        values={'self': backorder, 'origin': backorder.purchase_id},
-                        subtype_id=self.env.ref('mail.mt_note').id)
-        return res
-
 
 class StockMove(models.Model):
     _inherit = 'stock.move'