**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
'product_uom': fields.many2one('product.uom', 'Unit of Measure', required=True, states={'done': [('readonly', True)]}),
        'product_uos_qty': fields.float('Quantity (UOS)', digits_compute=dp.get_precision('Product UoS'), states={'done': [('readonly', True)]}),
        'product_uos': fields.many2one('product.uom', 'Product UOS', states={'done': [('readonly', True)]}),
        'product_tmpl_id': fields.related('product_id', 'product_tmpl_id', type='many2one', relation='product.template', string='Product Template'),
        'product_packaging': fields.many2one('product.packaging', 'Prefered Packaging', help="It specifies attributes of packaging like type, quantity of packaging,etc."),
        'location_id': fields.many2one('stock.location', 'Source Location', required=True, select=True, auto_join=True,
                                       states={'done': [('readonly', True)]}, help="Sets a location if you produce at a fixed location. This can be a partner location if you subcontract the manufacturing operations."),
        'location_dest_id': fields.many2one('stock.location', 'Destination Location', required=True, states={'done': [('readonly', True)]}, select=True,
                                            auto_join=True, help="Location where the system will stock the finished products."),
        'partner_id': fields.many2one('res.partner', 'Destination Address ', states={'done': [('readonly', True)]}, help="Optional address where goods are to be delivered, specifically used for allotment"),
        'move_dest_id': fields.many2one('stock.move', 'Destination Move', help="Optional: next stock move when chaining them", select=True, copy=False),
        'move_orig_ids': fields.one2many('stock.move', 'move_dest_id', 'Original Move', help="Optional: previous stock move when chaining them", select=True),
        'picking_id': fields.many2one('stock.picking', 'Reference', select=True, states={'done': [('readonly', True)]}),
        'note': fields.text('Notes'),
        'state': fields.selection([('draft', 'New'),
                                   ('cancel', 'Cancelled'),
                                   ('waiting', 'Waiting Another Move'),
                                   ('confirmed', 'Waiting Availability'),
                                   ('assigned', 'Available'),
                                   ('done', 'Done'),
                                   ], 'Status', readonly=True, select=True, copy=False,
                 help= "* New: When the stock move is created and not yet confirmed.\n"\
                       "* Waiting Another Move: This state can be seen when a move is waiting for another one, for example in a chained flow.\n"\
                       "* Waiting Availability: This state is reached when the procurement resolution is not straight forward. It may need the scheduler to run, a component to me manufactured...\n"\
                       "* Available: When products are reserved, it is set to \'Available\'.\n"\
                       "* Done: When the shipment is processed, the state is \'Done\'."),
        'partially_available': fields.boolean('Partially Available', readonly=True, help="Checks if the move has some stock reserved", copy=False),
        'price_unit': fields.float('Unit Price', help="Technical field used to record the product cost set by the user during a picking confirmation (when costing method used is 'average price' or 'real'). Value given in company currency and in product uom."),  
        'company_id': fields.many2one('res.company', 'Company', required=True, select=True),
        'split_from': fields.many2one('stock.move', string="Move Split From", help="Technical field used to track the origin of a split move, which can be useful in case of debug", copy=False),