During Blender 4.2's development, a bug was introduced that lead to volumes rendering incorrectly if: - There was a distant light with a zero angle spread - The light tree was enabled This was reported to blender/blender#129420 and fixed in 4.3. This commit adds a render test for this situation. Ref: blender/blender#123012 Ref: blender/blender-test-data!26 Pull Request: https://projects.blender.org/blender/blender/pulls/131079