old_contents: # -*- coding: utf-8 -*-
  # Part of Odoo. See LICENSE file for full copyright and licensing details.
  
  from odoo import api, fields, models
  
  
  class StockConfigSettings(models.TransientModel):
      _inherit = 'stock.config.settings'
  
      po_lead = fields.Float(related='company_id.po_lead', default=lambda self: self.env.user.company_id.po_lead)
      use_po_lead = fields.Boolean(
          string="Security Lead Time for Purchase",
          oldname='default_new_po_lead',
          help="Margin of error for vendor lead times. When the system generates Purchase Orders for reordering products,they will be scheduled that many days earlier to cope with unexpected vendor delays.")
  
      @api.onchange('use_po_lead')
      def _onchange_use_po_lead(self):
          if not self.use_po_lead:
              self.po_lead = 0.0
  
      def get_default_fields(self, fields):
          return dict(
              use_po_lead=self.env['ir.config_parameter'].sudo().get_param('purchase.use_po_lead')
          )
  
      def set_fields(self):
          self.env['ir.config_parameter'].sudo().set_param('purchase.use_po_lead', self.use_po_lead)
  
new_contents: # -*- coding: utf-8 -*-
  # Part of Odoo. See LICENSE file for full copyright and licensing details.
  
  from odoo import api, fields, models
  
  
  class StockConfigSettings(models.TransientModel):
      _inherit = 'stock.config.settings'
  
      po_lead = fields.Float(related='company_id.po_lead')
      use_po_lead = fields.Boolean(
          string="Security Lead Time for Purchase",
          oldname='default_new_po_lead',
          help="Margin of error for vendor lead times. When the system generates Purchase Orders for reordering products,they will be scheduled that many days earlier to cope with unexpected vendor delays.")
  
      @api.onchange('use_po_lead')
      def _onchange_use_po_lead(self):
          if not self.use_po_lead:
              self.po_lead = 0.0
  
      def get_default_fields(self, fields):
          return dict(
              use_po_lead=self.env['ir.config_parameter'].sudo().get_param('purchase.use_po_lead')
          )
  
      def set_fields(self):
          self.env['ir.config_parameter'].sudo().set_param('purchase.use_po_lead', self.use_po_lead)
  
subject: Remove useless default value for po_lead