IPAddressField inserted as empty string although null=True

[rihad@…]

I have these fields in a model:

        ipaddr1 = models.IPAddressField()
        ipaddr2 = models.IPAddressField(blank=True, null=True)

When I "wrap" this model in a ModelForm, fill the form, and call
form.save(), empty ipaddr2 gets inserted as an empty string, causing database
errors for Postgres' inet type.

I believe Django shouldn't be disregarding null=true for an IPAddressField when dealing with Postgres.

[anonymous]

Sorry for the dupe. Same problem as ​here.