Make GenericIPAddressField normalize IPv4 addresses

[Frank]

IPv4 addresses do not get normalized before storing them in the database. They are stored as Char fields in the database which can lead to both 127.0.0.010 and 127.0.0.10 being stored in the database, although the value should be unique.

[Tim Graham]

Does the behavior change justify breaking backwards compatibility (silently changing the input value)? Perhaps so, considering that PostgreSQL (and its native IP address data type) won't let you store duplicate values. It reports "Key (ip)=(192.168.1.10) already exists." for the two addresses you proposed -- so is the proper normalization to remove the leading zero?

[Frank]

Replying to timgraham:

Does the behavior change justify breaking backwards compatibility (silently changing the input value)? Perhaps so, considering that PostgreSQL (and its native IP address data type) won't let you store duplicate values. It reports "Key (ip)=(192.168.1.10) already exists." for the two addresses you proposed -- so is the proper normalization to remove the leading zero?

To start off, I do not really if you're advocating pro or con :-) But, I think the current situation is pretty bad. I mean, people can create models with addresses which they think have unique values. And in a sense this also goes against what you expect. You expect an generic ip address object to be evaluated as such, as an ip address, and not as a mere string value because it is stored as one. As far as I know, there is also not mention of this in the current documentation.

So, I also don't think that preserving backwards compatibility preservation is doing anyone a service in this matter. This might leave people having unreliable data.

As to what the proper normalization might be, I think removing the leading zeroes would be enough.

[Tim Graham]

I was mostly thinking out loud.

[KwonHan Bae]

I think is it possible to add django.utils.ipv4 ?
for ipv6 normalize, django have django.utils.ipv6.clean_ipv6_address.
but I think removing leading zero took about 5~6 lines function.
which namespace is proper to add this function? maybe name will be normalize_ipv4_address

[KwonHan Bae]

Ok I sent PR. ​https://github.com/django/django/pull/5424
please check it

[Sasha Gaevsky]

Updated ticket since related PR was closed.

[Mariusz Felisiak]

Leading zeros are not allowed anymore in IPv4 addresses. Fixed in e1d787f1b36d13b95187f8f425425ae1b98da188.