[FIX] product: remove the package when we unlink it from product

Steps to reproduce the bug:
- Enable “Product packing” in the inventory settings
- Create a storable product “P1”
    - Add a package with barcode “123”
    - save the changes
    - Delete the package
    - Try to set the same barcode “123” for the product

Problem:
A validation error is triggered: "A packaging already uses the barcode"

Solution:
When we delete the package from the product, we have to delete
completely the “product.packaging" record.

opw-3378288

closes odoo/odoo#131825

X-original-commit: d01d8a9cedec2d1c17469538103340fc934470f1
Signed-off-by: Arnold Moyaux (arm) <arm@odoo.com>
Signed-off-by: William Henrotin (whe) <whe@odoo.com>
Signed-off-by: Tiffany Chang (tic) <tic@odoo.com>

addons/product/models/product_packaging.py

@@ -17,7 +17,7 @@ class ProductPackaging(models.Model):
 
     name = fields.Char('Product Packaging', required=True)
     sequence = fields.Integer('Sequence', default=1, help="The first in the sequence is the default one.")
-    product_id = fields.Many2one('product.product', string='Product', check_company=True, required=True)
+    product_id = fields.Many2one('product.product', string='Product', check_company=True, required=True, ondelete="cascade")
     qty = fields.Float('Contained Quantity', default=1, digits='Product Unit of Measure', help="Quantity of products contained in the packaging.")
     barcode = fields.Char('Barcode', copy=False, help="Barcode used for packaging identification. Scan this packaging barcode from a transfer in the Barcode app to move all the contained units")
     product_uom_id = fields.Many2one('uom.uom', related='product_id.uom_id', readonly=True)

addons/product/tests/test_barcode.py

@@ -57,3 +57,19 @@ class TestProductBarcode(TransactionCase):
             assert 'Barcode "3" already assigned to product(s): BC3, BC4' in exc.args[0]
             assert 'Barcode "4" already assigned to product(s): BC5, BC6' in exc.args[0]
             assert 'Barcode "1" already assigned to product(s): BC1' in exc.args[0]
+
+    def test_delete_package_and_use_its_barcode_in_product(self):
+        """ Test that the barcode of the package can be used when the package is removed from the product."""
+        product = self.env['product.product'].create({
+            'name': 'product',
+            'packaging_ids': [(0, 0, {
+                'name': 'packing',
+                'barcode': '1234',
+            })]
+        })
+        package = product.packaging_ids
+        self.assertTrue(package.exists())
+        self.assertEqual(package.barcode, '1234')
+        product.packaging_ids = False
+        self.assertFalse(package.exists())
+        product.barcode = '1234'