Operating system: Linux-4.15.0-130-generic-x86_64-with-debian-buster-sid 64 Bits
Graphics card: AMD TURKS (DRM 2.50.0 / 4.15.0-130-generic, LLVM 10.0.0) X.Org 3.3 (Core Profile) Mesa 20.0.8
Broken: version: 2.91.0, branch: master, commit date: 2020-11-25 08:34, hash: rB0f45cab862b8
Worked: Blender 2.79 (possibly newer, these 2 versions are all I have).
Short description of error
When world color is black, white objects under white lights are rendered as black.
Exact steps for others to reproduce the error
- Open Blender 2.91 with default cube, light and camera.
- Go to World Properties tab, change Surface color of world to black.
- Press F12.
- The cube will be rendered totally black, even though it is a pale material with a light on it. This is not how lighting works, black does not project onto surfaces and override light.
Repeating these steps in Blender 2.79 produces correct results, rendering a visible pale cube.