[FIX] stock: no tracking for service product

Steps to reproduce the bug:
- Create a storable “P1”:
   - tracking= serial
   - save
- Change the type of product to service

Problem:
some fields for tracked products are not hidden, because the product
tracking is not updated.

Solution:
Convert _onchange_type into compute methods.
The tracking is updated even if the change type is applied from the
"product.product" form.

opw-3499976

closes odoo/odoo#135852

Signed-off-by: William Henrotin (whe) <whe@odoo.com>

addons/stock/models/product.py

@@ -601,7 +601,10 @@ class ProductTemplate(models.Model):
     tracking = fields.Selection([
         ('serial', 'By Unique Serial Number'),
         ('lot', 'By Lots'),
-        ('none', 'No Tracking')], string="Tracking", help="Ensure the traceability of a storable product in your warehouse.", default='none', required=True)
+        ('none', 'No Tracking')],
+        string="Tracking", required=True, default='none',
+        compute='_compute_tracking', store=True, readonly=False,
+        help="Ensure the traceability of a storable product in your warehouse.")
     description_picking = fields.Text('Description on Picking', translate=True)
     description_pickingout = fields.Text('Description on Delivery Orders', translate=True)
     description_pickingin = fields.Text('Description on Receptions', translate=True)
@@ -688,6 +691,12 @@ class ProductTemplate(models.Model):
             }
         return prod_available
 
+    @api.depends('type')
+    def _compute_tracking(self):
+        self.filtered(
+            lambda t: not t.tracking or t.type in ('consu', 'service') and t.tracking != 'none'
+        ).tracking = 'none'
+
     @api.model
     def _get_action_view_related_putaway_rules(self, domain):
         return {
@@ -744,8 +753,6 @@ class ProductTemplate(models.Model):
     @api.onchange('type')
     def _onchange_type(self):
         res = super(ProductTemplate, self)._onchange_type() or {}
-        if self.type == 'consu' and self.tracking != 'none':
-            self.tracking = 'none'
 
         # Return a warning when trying to change the product type
         if self.ids and self.product_variant_ids.ids and self.env['stock.move.line'].sudo().search_count([

addons/stock/tests/test_product.py

@@ -276,3 +276,22 @@ class TestVirtualAvailable(TestStockCommon):
         res = self.env['product.template'].name_search(name='123', operator='not ilike')
         res_ids = [r[0] for r in res]
         self.assertNotIn(template.id, res_ids)
+
+    def test_change_type_tracked_product(self):
+        product = self.env['product.template'].create({
+            'name': 'Brand new product',
+            'type': 'product',
+            'tracking': 'serial',
+        })
+        product_form = Form(product)
+        product_form.type = 'service'
+        product = product_form.save()
+        self.assertEqual(product.tracking, 'none')
+
+        product.type = 'product'
+        product.tracking = 'serial'
+        self.assertEqual(product.tracking, 'serial')
+        product_form = Form(product.product_variant_id)
+        product_form.type = 'service'
+        product = product_form.save()
+        self.assertEqual(product.tracking, 'none')