New texture refactor broke translucency on single-file texs

[ZZYZX]

When I say single-file, I'm referring to those in textures directory or inside TX_ markers.
Example wad attached. The image should be translucent.

It only looks correct with vid_rendermode 3, in all other renderers it's differently non-translucent.
Rendermode 1: https://i.imgur.com/3ydKM9F.png
Rendermode 4,0,2: https://i.imgur.com/xdowJep.png
Rendermode 3: https://i.imgur.com/3IypTsk.png

Reported against cc52f8937

[Graf Zahl]

Fixed for the hardware renderer. Why the true color software renderer isn't doing this right, but the softpoly renderer is, is something to be answered by someone else, preferably dpJudas.

[dpJudas]

I have no idea why it does this for the true color software renderer. It probably picks the wrong drawer.