Are you submitting a bug report or a feature request?

bug report

What is the current behavior?

Form doesn't rerender when going back from dirty state to pristine state

What is the expected behavior?

Form should rerender when going back from dirty state to pristine state

Sandbox Link

https://codesandbox.io/s/r9e0k

1. Change value from 'bla' to some other value
2. You'll see 'Is pristine: false'
3. Change value back to 'bla'
4. You'll see that 'Is pristine' is still false
5. Click 'get state' button
6. In the form state in console you'll see that pristine is true

Other information

Works fine in react-final-form@4.1.0