Don't set default value for on_change and set id

issue3487
review2501002

tryton/common/selection.py

@@ -45,7 +45,9 @@ class SelectionMixin(object):
 
         if 'relation' not in self.attrs:
             change_with = self.attrs.get('selection_change_with') or []
-            key = record._get_on_change_args(change_with).items()
+            args = record._get_on_change_args(change_with)
+            del args['id']
+            key = args.items()
             key.sort()
             self.init_selection(tuple(key))
         else:

tryton/gui/window/view_form/model/record.py

@@ -516,10 +516,11 @@ class Record(SignalEvent):
             scope = values
             for i in arg.split('.'):
                 if i not in scope:
-                    scope = None
                     break
                 scope = scope[i]
-            res[arg] = scope
+            else:
+                res[arg] = scope
+        res['id'] = self.id
         return res
 
     def on_change(self, fieldname, attr):