no need for custom sort when sort by _score

[babadofar]

This fixes #3973.
No tests or such, but it works for me ;)

[babadofar]

I was about to add a test but I'm having a hard time finding any tests for the discover controller? What to do?

[rashidkpc]

Yeah, test coverage for discover is pretty bad, we need to break that controller apart. Once we get a chance to repro #3973 we should be fine to merge this

[babadofar]

So, the reasoning behind this is that when you sort by _score, there is no need to use the createHitSortFn function, as the results are already sorted. I'm no big fan of giving user options to sort score ascending myself, but, of course, we are all different people with our own personal point of view.

This may perhaps be related to #4111

[ghost]

Jenkins standing by to test this. If you aren't a maintainer, you can ignore this comment. Someone with commit access, please review this and clear it for Jenkins to run; then say 'jenkins, test it'.

[rashidkpc]

@spalger with your recent work on _source sorting, is this still needed?

[spalger]

I think that @babadofar is right, #4111 will likely fix this. My recent work has been circling this but hasn't addressed this yet. On master I get this:

[spalger]

@BigFunger as you work on #4111 will you check if we do or don't need to add this?

[BigFunger]

Replaced by #4466