TimeField render returns None instead of 00:00:00

[ehumet]

Checklist

• I have verified that that issue exists against the master branch of Django REST framework.
• I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
• This is not a usage question. (Those should be directed to the discussion group instead.)
• This cannot be dealt with as a third party library. (We prefer new functionality to be in the form of third party libraries where possible.)
• I have reduced the issue to the simplest possible case.
• [] I have included a failing test as a pull request. (If you are unable to do so we can still accept the issue.)

Steps to reproduce

1. Create a model A with a TimeField B in it.
2. Create an instance C of the model A in which the TimeField B has a "00:00:00" value (midnight).
3. Create a default DRF serializer D for the model A.
4. Render the object C through serializer D

Expected behavior

It should render the TimeField B as "00:00:00".

Actual behavior

It actually gets rendered as None.

[tomchristie]

Confirmed.

[tomchristie]

Now resolved in master - thanks for raising the issue!