id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux 28159 Fix issues with InlineFormset.save_as_new in Django 1.11 Alexander Kavanaugh nobody "Django 1.11 now marks multipart POST data as immutable [(Release notes section)](https://docs.djangoproject.com/en/1.11/releases/1.11/#miscellaneous). This causes an issue with the private ``save_as_new`` feature in InlineFormsets: the set code in the conditional block [here](https://github.com/django/django/blob/master/django/forms/models.py#L886) now throws an AttributeError because the data it's attempting to change is marked as immutable. To restore previous behavior, this pull request turns off the immutability flag on the form data while the save_as_new functionality runs and turns immutability back on when the mutation code is complete. Note that the mutable flag isn't set if there is no data, hence the ``hasattr`` code. PR: https://github.com/django/django/pull/8448 " Bug new Forms 1.11 Normal inlineformset,save_as_new Unreviewed 1 0 0 0 0 0