**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.


picking_obj = self.pool.get('stock.picking')
        res = {}
        for picking_type_id in ids:
            
            picking_ids = picking_obj.search(cr, uid, [('picking_type_id', '=', picking_type_id), ('state', '=', 'done')], order='date_done desc', limit=10, context=context)
            tristates = []
            for picking in picking_obj.browse(cr, uid, picking_ids, context=context):
                if picking.date_done > picking.date:
                    tristates.insert(0, {'tooltip': picking.name or '' + ": " + _('Late'), 'value': -1})
                elif picking.backorder_id:
                    tristates.insert(0, {'tooltip': picking.name or '' + ": " + _('Backorder exists'), 'value': 0})
                else:
                    tristates.insert(0, {'tooltip': picking.name or '' + ": " + _('OK'), 'value': 1})
            res[picking_type_id] = json.dumps(tristates)
        return res
    def _get_picking_count(self, cr, uid, ids, field_names, arg, context=None):
        obj = self.pool.get('stock.picking')
        domains = {
            'count_picking_draft': [('state', '=', 'draft')],
            'count_picking_waiting': [('state', '=', 'confirmed')],
            'count_picking_ready': [('state', 'in', ('assigned', 'partially_available'))],
            'count_picking': [('state', 'in', ('assigned', 'waiting', 'confirmed', 'partially_available'))],
            'count_picking_late': [('min_date', '<', time.strftime(DEFAULT_SERVER_DATETIME_FORMAT)), ('state', 'in', ('assigned', 'waiting', 'confirmed', 'partially_available'))],
            'count_picking_backorders': [('backorder_id', '!=', False), ('state', 'in', ('confirmed', 'assigned', 'waiting', 'partially_available'))],
        }
        result = {}
        for field in domains:
            data = obj.read_group(cr, uid, domains[field] +