[FIX] stock: fix production_lot settings

For existing users who had previously disabled the "Lots & Serial
Numbers" settings, by applying this fix: https://github.com/odoo/odoo/pull/138907/commits/376ee1289eba840f1d8b2b6149d933bdedd47518

They will get the user error each time they try to access the settings.
Therefore, we prefer to prevent this and trigger the error only when
necessary.

opw-3452946

closes odoo/odoo#141921

X-original-commit: 608439b09cb68409dec10427d5b927ce0a27d526
Signed-off-by: William Henrotin (whe) <whe@odoo.com>
Signed-off-by: Djamel Touati (otd) <otd@odoo.com>

addons/stock/i18n/stock.pot

@@ -10225,6 +10225,15 @@ msgstr ""
 msgid "You have processed less products than the initial demand."
 msgstr ""
 
+#. module: stock
+#. odoo-python
+#: code:addons/stock/models/res_config_settings.py:0
+#, python-format
+msgid ""
+"You have product(s) in stock that have lot/serial number tracking enabled. \n"
+"Switch off tracking on all the products before switching off this setting."
+msgstr ""
+
 #. module: stock
 #. odoo-python
 #: code:addons/stock/models/product.py:0

addons/stock/models/res_config_settings.py

@@ -134,4 +134,8 @@ class ResConfigSettings(models.TransientModel):
                 ('show_operations', '=', False)
             ]).show_operations = True
 
+        if not self.group_stock_production_lot and previous_group.get('group_stock_production_lot'):
+            if self.env['product.product'].search_count([('tracking', '!=', 'none')], limit=1):
+                raise UserError(_("You have product(s) in stock that have lot/serial number tracking enabled. \nSwitch off tracking on all the products before switching off this setting."))
+
         return