[r313] Minor GL renderer issue - plutonia.wad MAP11

[Rachael]

Normally, I would not even bother posting a bug as trivial as this, but since it affects a commercial IWAD I figured maybe it would be a little bit more important than if it occurred in any other wad.

In Plutonia, starting in Map11, there's a room with a bunch of Archviles; you get to see them before they get scattered all over the place with teleporters.

The bug here is - the "bleed-through" effect for flats does not cross null-texture platforms. In Software rendering, this effect looks correct (of course, it's because this area is REALLY abusing the software rendering engine to pull this off). In GL mode, it creates a null-space which manifests itself as either showing the sky or a HOM effect. (In other words, it's not drawn)

I realize this may be a little bit trivial, possibly even unfixable (might break 3D floors?) but posting here just in case. Attached are screenshots in Software mode and GZDoom's OpenGL mode.

[Graf Zahl]

Normally this effect is properly handled. But in this case there is also a map bug present: One linedef bordering this invisible wall contains an incorrect sector reference which makes it close to impossible to so something about it. It just doesn't work with unclosed sectors.