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?).
""" It traces the information of lots
        @param self: The object pointer.
        @param cr: A database cursor
        @param uid: ID of the user currently logged in
        @param ids: List of IDs selected
        @param context: A standard dictionary
        @return: A dictionary of values
        """
        quant_obj = self.pool.get("stock.quant")
        quants = quant_obj.search(cr, uid, [('lot_id', 'in', ids)], context=context)
        moves = set()
        for quant in quant_obj.browse(cr, uid, quants, context=context):
            moves |= {move.id for move in quant.history_ids}
        if moves:
            return {
                'domain': "[('id','in',[" + ','.join(map(str, list(moves))) + "])]",
                'name': _('Traceability'),
                'view_mode': 'tree,form',
                'view_type': 'form',
                'context': {'tree_view_ref': 'stock.view_move_tree'},
                'res_model': 'stock.move',
                'type': 'ir.actions.act_window',
                    }
        return False
class stock_move(osv.osv):
    _name = "stock.move"
    _description = "Stock Move"
    _order = 'picking_id, sequence, id'
    def get_price_unit(self, cr, uid, move, context=None):