**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.


addons/stock/stock.py
'''This function computes the different product quantities for the given package
        '''
        quant_obj = self.pool.get('stock.quant')
        res = {}
        for quant in quant_obj.browse(cr, uid, self.get_content(cr, uid, package_id, context=context)):
            if quant.product_id.id not in res:
                res[quant.product_id.id] = 0
            res[quant.product_id.id] += quant.qty
        return res
    def copy_pack(self, cr, uid, id, default_pack_values=None, default=None, context=None):
        stock_pack_operation_obj = self.pool.get('stock.pack.operation')
        if default is None:
            default = {}
        new_package_id = self.copy(cr, uid, id, default_pack_values, context=context)
        default['result_package_id'] = new_package_id
        op_ids = stock_pack_operation_obj.search(cr, uid, [('result_package_id', '=', id)], context=context)
        for op_id in op_ids:
            stock_pack_operation_obj.copy(cr, uid, op_id, default, context=context)
class stock_pack_operation(osv.osv):
    _name = "stock.pack.operation"
    _description = "Packing Operation"
    def _get_remaining_prod_quantities(self, cr, uid, operation, context=None):