**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
"""
        Creates an extra move when there is no corresponding original move to be copied
        """
        uom_obj = self.pool.get("product.uom")
        uom_id = product.uom_id.id
        qty = remaining_qty
        if op.product_id and op.product_uom_id and op.product_uom_id.id != product.uom_id.id:
            if op.product_uom_id.factor > product.uom_id.factor: 
                uom_id = op.product_uom_id.id
                
                qty = uom_obj._compute_qty_obj(cr, uid, product.uom_id, remaining_qty, op.product_uom_id, rounding_method='HALF-UP')
        picking = op.picking_id
        ref = product.default_code
        name = '[' + ref + ']' + ' ' + product.name if ref else product.name
        res = {
            'picking_id': picking.id,
            'location_id': picking.location_id.id,
            'location_dest_id': picking.location_dest_id.id,
            'product_id': product.id,
            'product_uom': uom_id,
            'product_uom_qty': qty,
            'name': _('Extra Move: ') + name,
            'state': 'draft',
            'restrict_partner_id': op.owner_id.id,
            'group_id': picking.group_id.id,
            }
        return res
    def _create_extra_moves(self, cr, uid, picking, context=None):