[IMP]stock_account: Prevent user to set same valuation account and IN/OUT accounts.

In this commit use the python constraint to check the accounts if they are duplicate.

This change is because before this configuration there will be an entry cancelling another one in the same account,
resulting in a not impacted valuation account.

This commit is related to task #1908065.

closes odoo/odoo#28604

addons/point_of_sale/tests/test_anglo_saxon.py

@@ -24,12 +24,13 @@ class TestAngloSaxonCommon(common.TransactionCase):
         self.account = self.env['account.account'].create({'name': 'Receivable', 'code': 'RCV00' , 'user_type_id': account_type_rcv.id, 'reconcile': True})
         account_expense = self.env['account.account'].create({'name': 'Expense', 'code': 'EXP00' , 'user_type_id': account_type_oth.id, 'reconcile': True})
         account_output = self.env['account.account'].create({'name': 'Output', 'code': 'OUT00' , 'user_type_id': account_type_oth.id, 'reconcile': True})
+        account_valuation = self.env['account.account'].create({'name': 'Valuation', 'code': 'STV00', 'user_type_id': account_type_oth.id, 'reconcile': True})
         self.partner.property_account_receivable_id = self.account
         self.category.property_account_income_categ_id = self.account
         self.category.property_account_expense_categ_id = account_expense
         self.category.property_stock_account_input_categ_id = self.account
         self.category.property_stock_account_output_categ_id = account_output
-        self.category.property_stock_valuation_account_id = self.account
+        self.category.property_stock_valuation_account_id = account_valuation
         self.category.property_stock_journal = self.env['account.journal'].create({'name': 'Stock journal', 'type': 'sale', 'code': 'STK00'})
         self.pos_config = self.env.ref('point_of_sale.pos_config_main')
         self.pos_config = self.pos_config.copy({'name': 'New POS config'})

addons/sale_mrp/tests/test_sale_mrp_flow.py

@@ -405,12 +405,13 @@ class TestSaleMrpFlow(common.TransactionCase):
         self.account_receiv = self.env['account.account'].create({'name': 'Receivable', 'code': 'RCV00' , 'user_type_id': account_type.id, 'reconcile': True})
         account_expense = self.env['account.account'].create({'name': 'Expense', 'code': 'EXP00' , 'user_type_id': account_type.id, 'reconcile': True})
         account_output = self.env['account.account'].create({'name': 'Output', 'code': 'OUT00' , 'user_type_id': account_type.id, 'reconcile': True})
+        account_valuation = self.env['account.account'].create({'name': 'Valuation', 'code': 'STV00' , 'user_type_id': account_type.id, 'reconcile': True})
         self.partner.property_account_receivable_id = self.account_receiv
         self.category.property_account_income_categ_id = self.account_receiv
         self.category.property_account_expense_categ_id = account_expense
         self.category.property_stock_account_input_categ_id = self.account_receiv
         self.category.property_stock_account_output_categ_id = account_output
-        self.category.property_stock_valuation_account_id = self.account_receiv
+        self.category.property_stock_valuation_account_id = account_valuation
         self.category.property_stock_journal = self.env['account.journal'].create({'name': 'Stock journal', 'type': 'sale', 'code': 'STK00'})
 
         Product = self.env['product.product']

addons/stock_account/models/product.py

@@ -5,7 +5,7 @@ from odoo import api, fields, models, tools, _
 from odoo.exceptions import UserError
 from odoo.tools import float_is_zero, pycompat
 from odoo.addons import decimal_precision as dp
-
+from odoo.exceptions import ValidationError
 
 
 class ProductTemplate(models.Model):
@@ -394,6 +394,15 @@ class ProductCategory(models.Model):
         domain=[('deprecated', '=', False)],
         help="When real-time inventory valuation is enabled on a product, this account will hold the current value of the products.",)
 
+    @api.constrains('property_stock_valuation_account_id', 'property_stock_account_output_categ_id', 'property_stock_account_input_categ_id')
+    def _check_valuation_accouts(self):
+        # Prevent to set the valuation account as the input or output account.
+        for category in self:
+            valuation_account = category.property_stock_valuation_account_id
+            input_and_output_accounts = category.property_stock_account_input_categ_id | category.property_stock_account_output_categ_id
+            if valuation_account and valuation_account in input_and_output_accounts:
+                raise ValidationError(_('The Stock Input and/or Output accounts cannot be the same than the Stock Valuation account.'))
+
     @api.onchange('property_cost_method')
     def onchange_property_valuation(self):
         if not self._origin: