**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_type_code': fields.related('picking_type_id', 'code', type='char', string='Picking Type Code', help="Technical field used to display the correct label on print button in the picking view"),
        'owner_id': fields.many2one('res.partner', 'Owner', states={'done': [('readonly', True)], 'cancel': [('readonly', True)]}, help="Default Owner"),
        
        'product_id': fields.related('move_lines', 'product_id', type='many2one', relation='product.product', string='Product'),
        'recompute_pack_op': fields.boolean('Recompute pack operation?', help='True if reserved quants changed, which mean we might need to recompute the package operations', copy=False),
        'location_id': fields.related('move_lines', 'location_id', type='many2one', relation='stock.location', string='Location', readonly=True),
        'location_dest_id': fields.related('move_lines', 'location_dest_id', type='many2one', relation='stock.location', string='Destination Location', readonly=True),
        'group_id': fields.related('move_lines', 'group_id', type='many2one', relation='procurement.group', string='Procurement Group', readonly=True,
              store={
                  'stock.picking': (lambda self, cr, uid, ids, ctx: ids, ['move_lines'], 10),
                  'stock.move': (_get_pickings, ['group_id', 'picking_id'], 10),
              }),
    }
    _defaults = {
        'name': '/',
        'state': 'draft',
        'move_type': 'direct',
        'priority': '1',  
        'date': fields.datetime.now,
        'company_id': lambda self, cr, uid, c: self.pool.get('res.company')._company_default_get(cr, uid, 'stock.picking', context=c),
        'recompute_pack_op': True,
    }
    _sql_constraints = [
        ('name_uniq', 'unique(name, company_id)', 'Reference must be unique per company!'),
    ]
    def do_print_picking(self, cr, uid, ids, context=None):
        '''This function prints the picking list'''
        context = dict(context or {}, active_ids=ids)
        return self.pool.get("report").get_action(cr, uid, ids, 'stock.report_picking', context=context)
    def action_confirm(self, cr, uid, ids, context=None):