OCA · OCA-git-bot · Apr 24, 2026 · Apr 22, 2026
diff --git a/product_multi_company_stock/README.rst b/product_multi_company_stock/README.rst
@@ -1,7 +1,3 @@
-.. image:: https://odoo-community.org/readme-banner-image
-   :target: https://odoo-community.org/get-involved?utm_source=readme
-   :alt: Odoo Community Association
-
 ===========================
 Product multi-company Stock
 ===========================
@@ -17,7 +13,7 @@ Product multi-company Stock
 .. |badge1| image:: https://img.shields.io/badge/maturity-Beta-yellow.png
     :target: https://odoo-community.org/page/development-status
     :alt: Beta
-.. |badge2| image:: https://img.shields.io/badge/license-AGPL--3-blue.png
+.. |badge2| image:: https://img.shields.io/badge/licence-AGPL--3-blue.png
     :target: http://www.gnu.org/licenses/agpl-3.0-standalone.html
     :alt: License: AGPL-3
 .. |badge3| image:: https://img.shields.io/badge/github-OCA%2Fmulti--company-lightgray.png?logo=github
@@ -62,6 +58,7 @@ Contributors
 ------------
 
 - Joan Sisquella <joan.sisquella@forgeflow.com>
+- Lois Rilo <lois.rilo@forgeflow.com>
 
 Maintainers
 -----------

diff --git a/product_multi_company_stock/models/__init__.py b/product_multi_company_stock/models/__init__.py
@@ -1 +1,2 @@
 from . import product_template
+from . import stock_lot
diff --git a/product_multi_company_stock/models/stock_lot.py b/product_multi_company_stock/models/stock_lot.py
@@ -0,0 +1,23 @@
+# Copyright 2026 ForgeFlow S.L. (http://www.forgeflow.com)
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+from odoo import api, models
+
+
+class StockLot(models.Model):
+    _inherit = "stock.lot"
+
+    @api.depends("product_id.company_id", "product_id.company_ids")
+    def _compute_company_id(self):
+        # For lots belonging to single-company products, defer to standard logic.
+        # For multi-company products, preserve the stored company_id so that a
+        # change to product.company_ids (e.g. adding a third company) never
+        # overwrites the lot's original company — which would cause _check_unique_lot
+        # to fire when two lots share the same name across different companies.
+        single_company_lots = self.filtered(
+            lambda rec: len(rec.product_id.sudo().company_ids) == 1
+        )
+        res = super(StockLot, single_company_lots)._compute_company_id()
+        for lot in self - single_company_lots:
+            lot.company_id = lot._origin.company_id or lot.product_id.company_id
+        return res
diff --git a/product_multi_company_stock/readme/CONTRIBUTORS.md b/product_multi_company_stock/readme/CONTRIBUTORS.md
@@ -1 +1,2 @@
 - Joan Sisquella \<joan.sisquella@forgeflow.com\>
+- Lois Rilo \<lois.rilo@forgeflow.com\>
diff --git a/product_multi_company_stock/static/description/index.html b/product_multi_company_stock/static/description/index.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <meta name="generator" content="Docutils: https://docutils.sourceforge.io/" />
-<title>README.rst</title>
+<title>Product multi-company Stock</title>
 <style type="text/css">
 
 /*
@@ -360,21 +360,16 @@
 </style>
 </head>
 <body>
-<div class="document">
+<div class="document" id="product-multi-company-stock">
+<h1 class="title">Product multi-company Stock</h1>
 
-
-<a class="reference external image-reference" href="https://odoo-community.org/get-involved?utm_source=readme">
-<img alt="Odoo Community Association" src="https://odoo-community.org/readme-banner-image" />
-</a>
-<div class="section" id="product-multi-company-stock">
-<h1>Product multi-company Stock</h1>
 <!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 !! This file is generated by oca-gen-addon-readme !!
 !! changes will be overwritten.                   !!
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 !! source digest: sha256:c2890e80eee5fd642560a3ae22c4f14c520e904ef34406ceb5e2f3c938d111d8
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
-<p><a class="reference external image-reference" href="https://odoo-community.org/page/development-status"><img alt="Beta" src="https://img.shields.io/badge/maturity-Beta-yellow.png" /></a> <a class="reference external image-reference" href="http://www.gnu.org/licenses/agpl-3.0-standalone.html"><img alt="License: AGPL-3" src="https://img.shields.io/badge/license-AGPL--3-blue.png" /></a> <a class="reference external image-reference" href="https://github.com/OCA/multi-company/tree/18.0/product_multi_company_stock"><img alt="OCA/multi-company" src="https://img.shields.io/badge/github-OCA%2Fmulti--company-lightgray.png?logo=github" /></a> <a class="reference external image-reference" href="https://translation.odoo-community.org/projects/multi-company-18-0/multi-company-18-0-product_multi_company_stock"><img alt="Translate me on Weblate" src="https://img.shields.io/badge/weblate-Translate%20me-F47D42.png" /></a> <a class="reference external image-reference" href="https://runboat.odoo-community.org/builds?repo=OCA/multi-company&amp;target_branch=18.0"><img alt="Try me on Runboat" src="https://img.shields.io/badge/runboat-Try%20me-875A7B.png" /></a></p>
+<p><a class="reference external image-reference" href="https://odoo-community.org/page/development-status"><img alt="Beta" src="https://img.shields.io/badge/maturity-Beta-yellow.png" /></a> <a class="reference external image-reference" href="http://www.gnu.org/licenses/agpl-3.0-standalone.html"><img alt="License: AGPL-3" src="https://img.shields.io/badge/licence-AGPL--3-blue.png" /></a> <a class="reference external image-reference" href="https://github.com/OCA/multi-company/tree/18.0/product_multi_company_stock"><img alt="OCA/multi-company" src="https://img.shields.io/badge/github-OCA%2Fmulti--company-lightgray.png?logo=github" /></a> <a class="reference external image-reference" href="https://translation.odoo-community.org/projects/multi-company-18-0/multi-company-18-0-product_multi_company_stock"><img alt="Translate me on Weblate" src="https://img.shields.io/badge/weblate-Translate%20me-F47D42.png" /></a> <a class="reference external image-reference" href="https://runboat.odoo-community.org/builds?repo=OCA/multi-company&amp;target_branch=18.0"><img alt="Try me on Runboat" src="https://img.shields.io/badge/runboat-Try%20me-875A7B.png" /></a></p>
 <p>This modules does not allow to remove a company from company_ids if
 there is stock or moves in that company</p>
 <p><strong>Table of contents</strong></p>
@@ -390,29 +385,30 @@ <h1>Product multi-company Stock</h1>
 </ul>
 </div>
 <div class="section" id="bug-tracker">
-<h2><a class="toc-backref" href="#toc-entry-1">Bug Tracker</a></h2>
+<h1><a class="toc-backref" href="#toc-entry-1">Bug Tracker</a></h1>
 <p>Bugs are tracked on <a class="reference external" href="https://github.com/OCA/multi-company/issues">GitHub Issues</a>.
 In case of trouble, please check there if your issue has already been reported.
 If you spotted it first, help us to smash it by providing a detailed and welcomed
 <a class="reference external" href="https://github.com/OCA/multi-company/issues/new?body=module:%20product_multi_company_stock%0Aversion:%2018.0%0A%0A**Steps%20to%20reproduce**%0A-%20...%0A%0A**Current%20behavior**%0A%0A**Expected%20behavior**">feedback</a>.</p>
 <p>Do not contact contributors directly about support or help with technical issues.</p>
 </div>
 <div class="section" id="credits">
-<h2><a class="toc-backref" href="#toc-entry-2">Credits</a></h2>
+<h1><a class="toc-backref" href="#toc-entry-2">Credits</a></h1>
 <div class="section" id="authors">
-<h3><a class="toc-backref" href="#toc-entry-3">Authors</a></h3>
+<h2><a class="toc-backref" href="#toc-entry-3">Authors</a></h2>
 <ul class="simple">
 <li>ForgeFlow</li>
 </ul>
 </div>
 <div class="section" id="contributors">
-<h3><a class="toc-backref" href="#toc-entry-4">Contributors</a></h3>
+<h2><a class="toc-backref" href="#toc-entry-4">Contributors</a></h2>
 <ul class="simple">
 <li>Joan Sisquella &lt;<a class="reference external" href="mailto:joan.sisquella&#64;forgeflow.com">joan.sisquella&#64;forgeflow.com</a>&gt;</li>
+<li>Lois Rilo &lt;<a class="reference external" href="mailto:lois.rilo&#64;forgeflow.com">lois.rilo&#64;forgeflow.com</a>&gt;</li>
 </ul>
 </div>
 <div class="section" id="maintainers">
-<h3><a class="toc-backref" href="#toc-entry-5">Maintainers</a></h3>
+<h2><a class="toc-backref" href="#toc-entry-5">Maintainers</a></h2>
 <p>This module is maintained by the OCA.</p>
 <a class="reference external image-reference" href="https://odoo-community.org">
 <img alt="Odoo Community Association" src="https://odoo-community.org/logo.png" />
@@ -425,6 +421,5 @@ <h3><a class="toc-backref" href="#toc-entry-5">Maintainers</a></h3>
 </div>
 </div>
 </div>
-</div>
 </body>
 </html>
diff --git a/product_multi_company_stock/tests/test_product_multi_company_stock.py b/product_multi_company_stock/tests/test_product_multi_company_stock.py
@@ -1,5 +1,4 @@
-# Copyright 2025 ForgeFlow S.L.
-#   (http://www.forgeflow.com)
+# Copyright 2025-26 ForgeFlow S.L. (http://www.forgeflow.com)
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
 
 from odoo.exceptions import UserError
@@ -116,3 +115,46 @@ def test_remove_company_with_quants_or_moves_archived_product(self):
         with self.assertRaises(UserError) as error_move:
             product.write({"company_ids": [(6, 0, [self.company_2.id])]})
         self.assertIn("stock moves", str(error_move.exception))
+
+    def test_add_company_does_not_break_same_name_lots(self):
+        """Adding a company to a product must not affect existing lots.
+
+        Adding a new company to a product's company_ids triggers a
+        recompute of stock.lot.company_id (which depends on product_id.company_id).
+        should not change lots company.
+        """
+        product = self.env["product.product"].create(
+            {
+                "name": "Test Tracked Product",
+                "is_storable": True,
+                "tracking": "lot",
+                "company_ids": [(6, 0, [self.company_1.id, self.company_2.id])],
+            }
+        )
+        company_3 = self.company_obj.create({"name": "Test company 3"})
+        lot_1 = (
+            self.env["stock.lot"]
+            .with_company(self.company_1)
+            .create(
+                {
+                    "name": "LOT001",
+                    "product_id": product.id,
+                    "company_id": self.company_1.id,
+                }
+            )
+        )
+        lot_2 = (
+            self.env["stock.lot"]
+            .with_company(self.company_2)
+            .create(
+                {
+                    "name": "LOT001",
+                    "product_id": product.id,
+                    "company_id": self.company_2.id,
+                }
+            )
+        )
+        # Adding a third company should neither raise nor alter the lot companies.
+        product.write({"company_ids": [(4, company_3.id)]})
+        self.assertEqual(lot_1.company_id, self.company_1)
+        self.assertEqual(lot_2.company_id, self.company_2)
Original file line number	Diff line number	Diff line change
		@@ -1 +1,2 @@
		from . import product_template
		from . import stock_lot
Original file line number	Diff line number	Diff line change
		@@ -1 +1,2 @@
		- Joan Sisquella \<joan.sisquella@forgeflow.com\>
		- Lois Rilo \<lois.rilo@forgeflow.com\>