[FIX] stock: change product's company

Before this commit, there is no verification while changing a product's
company. That can lead to issue where some operations cannot be done
because of access errors.
To avoid that, this commit prevents to change the product's company if
some quants for this product exist in another company's location.

How to reproduce:
- Have at least two different companies (let say CompA and CompB);
- Create a new product who belong to no company;
- For this product, add quantity on hand in a CompA location;
- Now, change the product's company for the CompB;
- While selected only the CompA, go into the Inventory Adjustments and
  try to create a new inventory adjustment for the CompA location with
  this product's quant -> Access Error.

opw-3095984

closes odoo/odoo#110810

X-original-commit: 46987e13f35dc140869c58f6c5a09d9c542c3ae5
Signed-off-by: Tiffany Chang <tic@odoo.com>
Signed-off-by: Steve Van Essche <svs@odoo.com>

addons/stock/i18n/stock.pot

@@ -7964,6 +7964,14 @@ msgid ""
 "instead."
 msgstr ""
 
+#. module: stock
+#: code:addons/stock/models/product.py:0
+#, python-format
+msgid ""
+"This product's company cannot be changed as long as there are quantities of it"
+" belonging to another company."
+msgstr ""
+
 #. module: stock
 #: model:ir.model.fields,help:stock.field_stock_change_product_qty__new_quantity
 msgid ""

addons/stock/models/product.py

@@ -837,6 +837,18 @@ class ProductTemplate(models.Model):
 
     def write(self, vals):
         self._sanitize_vals(vals)
+        if 'company_id' in vals and vals['company_id']:
+            products_changing_company = self.filtered(lambda product: product.company_id.id != vals['company_id'])
+            if products_changing_company:
+                # Forbid changing a product's company when quant(s) exist in another company.
+                quant = self.env['stock.quant'].sudo().search([
+                    ('product_id', 'in', products_changing_company.product_variant_ids.ids),
+                    ('company_id', '!=', vals['company_id']),
+                    ('quantity', '!=', 0),
+                ], order=None, limit=1)
+                if quant:
+                    raise UserError(_("This product's company cannot be changed as long as there are quantities of it belonging to another company."))
+
         if 'uom_id' in vals:
             new_uom = self.env['uom.uom'].browse(vals['uom_id'])
             updated = self.filtered(lambda template: template.uom_id != new_uom)

addons/stock/tests/test_product.py

@@ -5,6 +5,7 @@
 # Copyright 2015 Camptocamp SA
 
 from odoo.addons.stock.tests.common2 import TestStockCommon
+from odoo.exceptions import UserError
 from odoo.tests.common import Form
 
 
@@ -102,6 +103,33 @@ class TestVirtualAvailable(TestStockCommon):
         self.product_3.active = False
         self.assertFalse(orderpoint.active)
 
+    def test_change_product_company(self):
+        """ Checks we can't change the product's company if this product has
+        quant in another company. """
+        company1 = self.env.ref('base.main_company')
+        company2 = self.env['res.company'].create({'name': 'Second Company'})
+        product = self.env['product.product'].create({
+            'name': 'Product [TEST - Change Company]',
+            'type': 'product',
+        })
+        # Creates a quant for productA in the first company.
+        self.env['stock.quant'].create({
+            'product_id': product.id,
+            'product_uom_id': self.uom_unit.id,
+            'location_id': self.location_1.id,
+            'quantity': 7,
+            'reserved_quantity': 0,
+        })
+        # Assigns a company: should be OK for company1 but should raise an error for company2.
+        product.company_id = company1.id
+        with self.assertRaises(UserError):
+            product.company_id = company2.id
+        # Checks we can assing company2 for the product once there is no more quant for it.
+        quant = self.env['stock.quant'].search([('product_id', '=', product.id)])
+        quant.quantity = 0
+        self.env['stock.quant']._unlink_zero_quants()
+        product.company_id = company2.id  # Should work this time.
+
     def test_search_qty_available(self):
         product = self.env['product.product'].create({
             'name': 'Brand new product',