[FIX] sale_coupon: correct discount application values from view

Create a coupon program following these steps:

- Set name
- set 'Discount Apply On' to 'On Specific Product'
- Add specific product
- Set 'Apply Discount' to Fixed price
- Input the fixed price
- Save

Generate a coupon and try to apply it on a quotation.
Error will popup because Not all conditions are met.

The field discount_apply_on (invisible with fixed price) keep the
application "specific_products". Fixing by checking the values in the
backend.

opw-2257783

closes odoo/odoo#51574

Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/addons/coupon/models/coupon_program.py b/addons/coupon/models/coupon_program.py
index f9b080df2e4..3232ab63947 100644
--- a/addons/coupon/models/coupon_program.py
+++ b/addons/coupon/models/coupon_program.py
@@ -77,6 +77,11 @@ class CouponProgram(models.Model):
         if self.reward_product_id:
             self.reward_product_uom_id = self.reward_product_id.uom_id
 
+    @api.onchange('discount_type')
+    def _onchange_discount_type(self):
+        if self.discount_type == 'fixed_amount':
+            self.discount_apply_on = 'on_order'
+
     @api.model
     def create(self, vals):
         program = super(CouponProgram, self).create(vals)