Add missing parent_name to ModelRecordGroup instance in O2M

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

@@ -338,7 +338,7 @@ class O2MField(CharField):
     def create(self, model):
         from group import ModelRecordGroup
         mod = ModelRecordGroup(self.attrs['relation'], {}, model.window,
-                parent=model)
+                parent=model, parent_name=self.attrs.get('relation_field', ''))
         mod.signal_connect(mod, 'model-changed', self._model_changed)
         return mod
 
@@ -413,7 +413,8 @@ class O2MField(CharField):
                 return False
 
         model.value[self.name] = ModelRecordGroup(
-                self.attrs['relation'], fields, model.window, parent=model)
+                self.attrs['relation'], fields, model.window, parent=model,
+                parent_name=self.attrs.get('relation_field', ''))
         model.value[self.name].signal_connect(model.value[self.name],
                 'model-changed', self._model_changed)
         mod = None