                  base = base._meta.concrete_model
                  if base in o2o_map:
                      field = o2o_map[base]
                  elif not is_proxy:
                      attr_name = '%s_ptr' % base._meta.module_name
                      field = OneToOneField(base, name=attr_name,
                              auto_created=True, parent_link=True)
                      new_class.add_to_class(attr_name, field)
                  else:
                      field = None
 
</s> remove         self.name = '%s:%s' % (self.opts.app_label, self.opts.module_name)
        self.var_name = self.opts.object_name.lower()
 </s> add         self.name = '%s:%s' % (self.opts.app_label, self.opts.model_name)
        self.var_name = self.opts.model_name </s> remove                 {'%s__isnull' % self.parent_model._meta.module_name: False})
 </s> add                 {'%s__isnull' % self.parent_model._meta.model_name: False}) </s> remove         self.module_name, self.verbose_name = None, None
 </s> add         self.model_name, self.verbose_name = None, None </s> remove             opts.app_label, opts.object_name.lower(),
 </s> add             opts.app_label, opts.model_name, </s> remove         if m._meta.object_name.lower() == model_name:
 </s> add         if m._meta.model_name == model_name:
                    attr_name = '%s_ptr' % base._meta.model_name
                  base = base._meta.concrete_model
                  if base in o2o_map:
                      field = o2o_map[base]
                  elif not is_proxy:
                    attr_name = '%s_ptr' % base._meta.model_name
                      field = OneToOneField(base, name=attr_name,
                              auto_created=True, parent_link=True)
                      new_class.add_to_class(attr_name, field)
                  else:
                      field = None
keep keep keep keep replace keep keep keep keep keep
 Fixed #19689 -- Renamed `Model._meta.module_name` to `model_name`. 
django/db/models/base.py