[FIX] sale: making an advance payment in percent

When making an advance payment in percent, the function onchange_advance_payment_method
set the Down Payment Product to False. Then each time an advanced payment in percent
was made, a new down payment product was created and set in sale.config.setting in the field
deposit_product_id_setting.

Now the function onchange_advance_payment_method let the Down Payment Product
even if the payment method is in percent.

opw:683167

addons/sale/wizard/sale_make_invoice_advance.py

@@ -23,6 +23,19 @@ class SaleAdvancePaymentInv(models.TransientModel):
                 return 'all'
         return 'delivered'
 
+    @api.model
+    def _default_product_id(self):
+        product_id = self.env['ir.values'].get_default('sale.config.settings', 'deposit_product_id_setting')
+        return self.env['product.product'].browse(product_id)
+
+    @api.model
+    def _default_deposit_account_id(self):
+        return self._default_product_id().property_account_income_id
+
+    @api.model
+    def _default_deposit_taxes_id(self):
+        return self._default_product_id().taxes_id
+
     advance_payment_method = fields.Selection([
         ('delivered', 'Invoiceable lines'),
         ('all', 'Invoiceable lines (deduct down payments)'),
@@ -30,17 +43,17 @@ class SaleAdvancePaymentInv(models.TransientModel):
         ('fixed', 'Down payment (fixed amount)')
         ], string='What do you want to invoice?', default=_get_advance_payment_method, required=True)
     product_id = fields.Many2one('product.product', string='Down Payment Product', domain=[('type', '=', 'service')],\
-        default=lambda self: self.env['ir.values'].get_default('sale.config.settings', 'deposit_product_id_setting'))
+        default=_default_product_id)
     count = fields.Integer(default=_count, string='# of Orders')
     amount = fields.Float('Down Payment Amount', digits=dp.get_precision('Account'), help="The amount to be invoiced in advance, taxes excluded.")
     deposit_account_id = fields.Many2one("account.account", string="Income Account", domain=[('deprecated', '=', False)],\
-        help="Account used for deposits")
-    deposit_taxes_id = fields.Many2many("account.tax", string="Customer Taxes", help="Taxes used for deposits")
+        help="Account used for deposits", default=_default_deposit_account_id)
+    deposit_taxes_id = fields.Many2many("account.tax", string="Customer Taxes", help="Taxes used for deposits", default=_default_deposit_taxes_id)
 
     @api.onchange('advance_payment_method')
     def onchange_advance_payment_method(self):
         if self.advance_payment_method == 'percentage':
-            return {'value': {'amount':0, 'product_id':False}}
+            return {'value': {'amount': 0}}
         return {}
 
     @api.multi