Dima Kogan <dima@secretsauce.net> writes:

> This is what I'd expect. After the fix (i.e. if
> fill-indent-according-to-mode is t) I get this:
>
>
> r'''aaa
>
> this is a test this is a test this is a test this is a test this is a
>  test this is a test
>
> '''
>
>
> For some reason it now wants to add one space at the beginning of every
> line in a paragraph except the first. Is there some interpretation where
> this the "correct" behavior?

Thanks for reporting this.  The problem seems to be that fill-newline
puts the space on the new line when breaking the line, and
python-indent-line (which is called when fill-indent-according-to-mode
is t) leaves indentation inside strings as-is.

Maybe the solution is to bind fill-indent-according-to-mode only during
auto-filling?  The patch below seems to work for both this bug's OP, and
your case.