[10.0][FIX] purchase_packaging: related field product_tmpl_id on purchase order line must be readonly

purchase_packaging/__manifest__.py

@@ -3,7 +3,7 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 {
     "name": "Purchase Packaging",
-    "version": "10.0.1.0.4",
+    "version": "10.0.1.0.5",
     "author": 'ACSONE SA/NV, '
               'Odoo Community Association (OCA)',
     "category": "Warehouse",

purchase_packaging/models/purchase_order_line.py

@@ -14,7 +14,8 @@ class PurchaseOrderLine(models.Model):
 
     product_tmpl_id = fields.Many2one(
         related='product_id.product_tmpl_id',
-        comodel_name='product.template'
+        comodel_name='product.template',
+        readonly=True
     )
     packaging_id = fields.Many2one(
         'product.packaging',