**Impacted versions:** 8.0

**Steps to reproduce:**
To reproduce it is necessary the fifo configuration in the assignation of quants in moves.

- Create a sale order with two lines of the same product, one of that line with a route that generate moves between warehouse.

<img width="1231" alt="skitch 65" src="https://cloud.githubusercontent.com/assets/11341058/24102907/d575a638-0d53-11e7-922e-a3f034d43e94.png">

The route used has three pull rules:

1. From Stock Warehouse_1 to Virtual Locations/Inter Company Transit
2. From Virtual Locations/Inter Company Transit to Stock Warehouse_2
3. From Stock Warehouse_2 to Customers

<img width="1224" alt="skitch 66" src="https://cloud.githubusercontent.com/assets/11341058/24103147/b7c2bfbc-0d54-11e7-955c-87247a10e0bd.png">

- Confirm the sale order. It must be created three pickings:

<img width="1226" alt="skitch 67" src="https://cloud.githubusercontent.com/assets/11341058/24103498/d90c9b38-0d55-11e7-97ff-f986df8cdd9b.png">

- Transfer first two pickings.

<img width="1230" alt="skitch 70" src="https://cloud.githubusercontent.com/assets/11341058/24104496/b7b0be8a-0d58-11e7-89a2-4331fceec1d8.png">

- Before transfer third picking, review that one move has reserved the quant correctly because was reserved from the previous pickings.

<img width="1215" alt="skitch 68" src="https://cloud.githubusercontent.com/assets/11341058/24103908/23952cc8-0d57-11e7-9346-bd48d7edb54a.png">

**Current behavior:**

When check availability of this third picking, the quant already reserved is moved to the other move.

<img width="1264" alt="skitch 69" src="https://cloud.githubusercontent.com/assets/11341058/24104056/8be11616-0d57-11e7-8763-a90507315b19.png">
 
**Expected behavior:**

When check availability of this third picking, the moves already reserved must not be altered.


""" just split the picking (create a backorder) without making it 'done' """
        if context is None:
            context = {}
        ctx = context.copy()
        ctx['do_only_split'] = True
        return self.do_transfer(cr, uid, picking_ids, context=ctx)
    def get_next_picking_for_ui(self, cr, uid, context=None):
        """ returns the next pickings to process. Used in the barcode scanner UI"""
        if context is None:
            context = {}
        domain = [('state', 'in', ('assigned', 'partially_available'))]
        if context.get('default_picking_type_id'):
            domain.append(('picking_type_id', '=', context['default_picking_type_id']))
        return self.search(cr, uid, domain, context=context)
    def action_done_from_ui(self, cr, uid, picking_id, context=None):
        """ called when button 'done' is pushed in the barcode scanner UI """
        
        pack_op_obj = self.pool.get('stock.pack.operation')
        for operation in self.browse(cr, uid, picking_id, context=context).pack_operation_ids:
            pack_op_obj.write(cr, uid, operation.id, {'product_qty': operation.qty_done}, context=dict(context, no_recompute=True))
        self.do_transfer(cr, uid, [picking_id], context=context)
        
        return self.get_next_picking_for_ui(cr, uid, context=context)
    @api.cr_uid_ids_context
    def action_pack(self, cr, uid, picking_ids, operation_filter_ids=None, context=None):