Documentation on formsets lists incomplete code to detect errors in clean()

[Tiemo]

The documentation on FormSets at ​https://docs.djangoproject.com/en/2.2/topics/forms/formsets/ lists incomplete sample code to determine whether the formset has erorrs in clean().

The listing:

>>> class BaseArticleFormSet(BaseFormSet):
...     def clean(self):
...         """Checks that no two articles have the same title."""
...         if any(self.errors):
...             # Don't bother validating the formset unless each form is valid on its own
...             return

This check is not complete, the full_clean method calls form.errors on all forms in the formset at r349, even on forms that are to be removed. This results in self.errors containing errors for forms that are to be deleted.

However, FormSet.is_valid ignores errors in forms that are to be removed.

The result is that the any(self.errors) snippet returns True, even if only removed forms contain errors.

[Carlton Gibson]

Since f32d24652b920135eb6a0f3de74599f03e181731 forms that are to be deleted do not have their errors appended to the formset's errors.