**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
move_quants = move.reserved_quant_ids
                picking_quants += move_quants
                forced_qty = (move.state == 'assigned') and move.product_qty - sum([x.qty for x in move_quants]) or 0
                
                if float_compare(forced_qty, 0, precision_rounding=move.product_id.uom_id.rounding) > 0:
                    if forced_qties.get(move.product_id):
                        forced_qties[move.product_id] += forced_qty
                    else:
                        forced_qties[move.product_id] = forced_qty
            for vals in self._prepare_pack_ops(cr, uid, picking, picking_quants, forced_qties, context=context):
                pack_operation_obj.create(cr, uid, vals, context=ctx)
        
        self.do_recompute_remaining_quantities(cr, uid, picking_ids, context=context)
        self.write(cr, uid, picking_ids, {'recompute_pack_op': False}, context=context)
    @api.cr_uid_ids_context
    def do_unreserve(self, cr, uid, picking_ids, context=None):
        """
          Will remove all quants for picking in picking_ids
        """
        moves_to_unreserve = []
        pack_line_to_unreserve = []
        for picking in self.browse(cr, uid, picking_ids, context=context):
            moves_to_unreserve += [m.id for m in picking.move_lines if m.state not in ('done', 'cancel')]
            pack_line_to_unreserve += [p.id for p in picking.pack_operation_ids]
        if moves_to_unreserve:
            if pack_line_to_unreserve:
                self.pool.get('stock.pack.operation').unlink(cr, uid, pack_line_to_unreserve, context=context)
            self.pool.get('stock.move').do_unreserve(cr, uid, moves_to_unreserve, context=context)
    def recompute_remaining_qty(self, cr, uid, picking, context=None):
        def _create_link_for_index(operation_id, index, product_id, qty_to_assign, quant_id=False):