BooleanField should not use False as default (unless provided)

[Andrew Badr]

Steps to repro:
1) Make a Model with a BooleanField with no default
2) Instantiate that model with no initial value
3) The value of the BooleanField on that instance is False

Expected behavior:
3) The value of the BooleanField on that instance is None

Guessing a value for the field is wrong. Attempting to save a model with a non-null field without providing a value for that field should be an error. (Postgres of course throws an error if you try to insert a row with no value for a required bool field.) It's ok for CharFields with blank=True to default to the empty string, because that's semantically the lack of a value for the field. However, True and False are equals; False is not the lack of a value.

Note the existence of the opposite ticket, #2855, which was wontfix'd then apparently silently "fixed" at some point.

[Russell Keith-Magee]

Discussion on ​django-dev

[Andrew Badr]

Fix + test + fix for unrelated test

[Alex Gaynor]

So apparently I hadn't noticed this before, but this will almost certainly break code I have, likely others as well.

[Andrew Badr]

Likely, but the current behavior is (1) wrong, (2) undocumented, (3) arguably untested, and (4) has already changed in the past. The bug should be fixed for 1.3 but (as Russ says) not backported.

[Aymeric Augustin]

I just read the thread and it seems to me that the majority is in favor of fixing this bug.

[neaf]

Add documentation and release notes mention.

[Aleksandra Sendecka]

Works ok. Tests and docs are there, so RFC.

[Aleksandra Sendecka]

Fix with tests and docs with realease notes for 1.4-beta-1 instead of 1.4

[chomik]

change marked as backwards incompatibile in release notes

[chomik]

corrects 15124.v2 FlatPage BooleanFields to have default value

[Béres Botond]

Combined and updated prev. patches to apply cleanly. Added doc entry to model fields

[Carl Meyer]

My take here is that this is a legitimate bugfix and should go in, but there's enough potential for breakage of existing code that I'm hesitant to drop it in after the beta, I'd rather target it for 1.5 at this point.

[Tomek Paczkowski]

We're after 1.4. This should go in now, I guess.

[Tomek Paczkowski]

Updated patch to current effort (1.5)

[Aymeric Augustin <aymeric.augustin@…>]

In e16c48e001ccd06830bb0bfd1d20e22ec30fce59:

Fixed #15124 -- Changed the default for BooleanField.

Thanks to the many contributors who updated and improved the patch over
the life of this ticket.