Water physics bug

Not sure if this is a bug and/or if this happened in earlier versions too. I know water at first tries to look for an empty spot one layer below and flows there. If you place a sand block below where the water streams are flowing to it should fix itself.

It's bug.

If you place a torch in the empty spot does water fill it?

No.

Can you post the world seed + coordinates?

Duplicate of MC-916.