**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
""" The meaning of product_qty field changed lately and is now a functional field computing the quantity
            in the default product UoM. This code has been added to raise an error if a write is made given a value
            for `product_qty`, where the same write should set the `product_uom_qty` field instead, in order to
            detect errors.
        """
        raise osv.except_osv(_('Programming Error!'), _('The requested operation cannot be processed because of a programming error setting the `product_qty` field instead of the `product_uom_qty`.'))
    _columns = {
        'name': fields.char('Description', required=True, select=True),
        'priority': fields.selection(procurement.PROCUREMENT_PRIORITIES, 'Priority'),
        'create_date': fields.datetime('Creation Date', readonly=True, select=True),
        'date': fields.datetime('Date', required=True, select=True, help="Move date: scheduled date until move is done, then date of actual move processing", states={'done': [('readonly', True)]}),
        'date_expected': fields.datetime('Expected Date', states={'done': [('readonly', True)]}, required=True, select=True, help="Scheduled date for the processing of this move"),
        'product_id': fields.many2one('product.product', 'Product', required=True, select=True, domain=[('type', '<>', 'service')], states={'done': [('readonly', True)]}),
        'product_qty': fields.function(_quantity_normalize, fnct_inv=_set_product_qty, type='float', digits=0, store={
            _name: (lambda self, cr, uid, ids, c={}: ids, ['product_id', 'product_uom', 'product_uom_qty'], 10),
        }, string='Quantity',
            help='Quantity in the default UoM of the product'),
        'product_uom_qty': fields.float('Quantity', digits_compute=dp.get_precision('Product Unit of Measure'),
            required=True, states={'done': [('readonly', True)]},
            help="This is the quantity of products from an inventory "
                "point of view. For moves in the state 'done', this is the "
                "quantity of products that were actually moved. For other "
                "moves, this is the quantity of product that is planned to "
                "be moved. Lowering this quantity does not generate a "
                "backorder. Changing this quantity on assigned moves affects "
                "the product reservation, and should be done with care."
        ),