I have no idea why software does this.
Edited by Lactozilla
changed the description
I... don't see the difference?
I only saw one difference, the lines on the right are not as curved as the first image, being the same as OpenGL.
The sky is stretched vertically less.
The sky is the same between pre and post patch screenshots. OpenGL has a less stretched sky (#189).
The bending of the floor texture gets removed by the patch.
Clearly you do have an idea, considering you knew how to fix it. ;)
merged