**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
inventory_line_obj = self.pool.get('stock.inventory.line')
        for inventory in self.browse(cr, uid, ids, context=context):
            
            line_ids = [line.id for line in inventory.line_ids]
            if not line_ids and inventory.filter != 'partial':
                
                vals = self._get_inventory_lines(cr, uid, inventory, context=context)
                for product_line in vals:
                    inventory_line_obj.create(cr, uid, product_line, context=context)
        return self.write(cr, uid, ids, {'state': 'confirm', 'date': time.strftime(DEFAULT_SERVER_DATETIME_FORMAT)})
    def _get_inventory_lines(self, cr, uid, inventory, context=None):
        location_obj = self.pool.get('stock.location')
        product_obj = self.pool.get('product.product')
        location_ids = location_obj.search(cr, uid, [('id', 'child_of', [inventory.location_id.id])], context=context)
        domain = ' location_id in %s'
        args = (tuple(location_ids),)
        if inventory.partner_id:
            domain += ' and owner_id = %s'
            args += (inventory.partner_id.id,)
        if inventory.lot_id:
            domain += ' and lot_id = %s'
            args += (inventory.lot_id.id,)
        if inventory.product_id:
            domain += ' and product_id = %s'
            args += (inventory.product_id.id,)
        if inventory.package_id:
            domain += ' and package_id = %s'
            args += (inventory.package_id.id,)
        cr.execute('''
           SELECT product_id, sum(qty) as product_qty, location_id, lot_id as prod_lot_id, package_id, owner_id as partner_id