Impacted versions: 9.0

Steps to reproduce:

* Create an MTO product with 
  * Product Type: Stockable Product
  * Routes: "Buy" and "Make to Order"
* Update Qty on Hand to any quantity (i.e, 2).
* Create a sales order with this product and a number <= to the one in the step before.
* Confirm the sales order.

Current behavior:

The created delivery picking appears in state "Reserved" and the current quantity on stock has been reserved, allowing you to transfer that stock.

Expected behavior:

The created delivery picking should be in "Waiting another operation", or at least in "Waiting availability" until the purchase order is confirmed (if you have defined a supplier for the product and the procurement creates the purchase order), which seems to be the current behavior when there's no stock available (is this also correct, as it allows to manually reserve?).
addons/stock/stock.py
_name = "stock.incoterms"
    _description = "Incoterms"
    _columns = {
        'name': fields.char('Name', required=True, help="Incoterms are series of sales terms. They are used to divide transaction costs and responsibilities between buyer and seller and reflect state-of-the-art transportation practices."),
        'code': fields.char('Code', size=3, required=True, help="Incoterm Standard Code"),
        'active': fields.boolean('Active', help="By unchecking the active field, you may hide an INCOTERM you will not use."),
    }
    _defaults = {
        'active': True,
    }
class stock_location(osv.osv):
    _name = "stock.location"
    _description = "Inventory Locations"
    _parent_name = "location_id"
    _parent_store = True
    _parent_order = 'name'
    _order = 'parent_left'
    _rec_name = 'complete_name'
    def _location_owner(self, cr, uid, location, context=None):