Refraction is broken (regression from 772485c)

[djrm]

Operating system or device - Godot version:
Fedora 26, NVidia GTX900 Series, Propietary Driver

Issue description:

Enabling Refraction turns the material to an opaque pink color

Steps to reproduce:
Just enable refraction on a non opaque material.

Link to minimal example project:

[vnen]

Have this problem too and I'm still suffering from #9139.

[rubenjavier]

Have the same problem, the ice on the godot-demo-projects for master [3.0] is broken.
Linux Ubuntu 16.04 64bits

[ghost]

Can confirm, same driver.
The issue comes with 772485c.

[djrm]

This seems to partially work when DOF is enabled:

[djrm]

This one was fixed as well, probably by f5277e3, im unable to reproduce it.