**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
'''This function reserves quants for the given move (and optionally given link). If the total of quantity reserved is enough, the move's state
        is also set to 'assigned'
        :param quants: list of tuple(quant browse record or None, qty to reserve). If None is given as first tuple element, the item will be ignored. Negative quants should not be received as argument
        :param move: browse record
        :param link: browse record (stock.move.operation.link)
        '''
        toreserve = []
        reserved_availability = move.reserved_availability
        
        for quant, qty in quants:
            if qty <= 0.0 or (quant and quant.qty <= 0.0):
                raise osv.except_osv(_('Error!'), _('You can not reserve a negative quantity or a negative quant.'))
            if not quant:
                continue
            self._quant_split(cr, uid, quant, qty, context=context)
            toreserve.append(quant.id)
            reserved_availability += quant.qty
        
        if toreserve:
            self.write(cr, SUPERUSER_ID, toreserve, {'reservation_id': move.id}, context=context)
            
            if move.picking_id:
                self.pool.get('stock.picking').write(cr, uid, [move.picking_id.id], {'recompute_pack_op': True}, context=context)
        
        rounding = move.product_id.uom_id.rounding
        if float_compare(reserved_availability, move.product_qty, precision_rounding=rounding) == 0 and move.state in ('confirmed', 'waiting')  :
            self.pool.get('stock.move').write(cr, uid, [move.id], {'state': 'assigned'}, context=context)
        elif float_compare(reserved_availability, 0, precision_rounding=rounding) > 0 and not move.partially_available:
            self.pool.get('stock.move').write(cr, uid, [move.id], {'partially_available': True}, context=context)
    def quants_move(self, cr, uid, quants, move, location_to, location_from=False, lot_id=False, owner_id=False, src_package_id=False, dest_package_id=False, context=None):