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Diffstat (limited to 'django/forms/utils.py')
| -rw-r--r-- | django/forms/utils.py | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/django/forms/utils.py b/django/forms/utils.py index 14253f36fe..f5fc0515a5 100644 --- a/django/forms/utils.py +++ b/django/forms/utils.py @@ -138,6 +138,15 @@ class ErrorList(UserList, list): return list(error)[0] return force_text(error) + def __reduce_ex__(self, *args, **kwargs): + # The `list` reduce function returns an iterator as the fourth element + # that is normally used for repopulating. Since we only inherit from + # `list` for `isinstance` backward compatibility (Refs #17413) we + # nullify this iterator as it would otherwise result in duplicate + # entries. (Refs #23594) + info = super(UserList, self).__reduce_ex__(*args, **kwargs) + return info[:3] + (None, None) + # Utilities for time zone support in DateTimeField et al. |