Sprite color flicker with certain dynamic light parameters

[Sinael]

When using the following combo of parameters:

Code: Select all

autoloadlights=true
autoloadbrightmaps=true
disableautoload=false
gl_light_particles=false
gl_light_sprites=false

Sprites would randomly flicker with red (rarely blue) fullbright color. Barely happens on maps with low sprite count, but very noticable on bigger (1000+ enemies) maps.
Even noticeable on the start of Doom 2, during the screenwipe two zombiemen and armor pickup would be lit up red, but rarely happens otherwise since sprite count is low.

To reproduce:
* Fresh install GZDoom
* Launch once to generate .ini
* Set CVARs mentioned above to the said values.
* Load map with big monstercound and have many monsters on screen.
* Move mouse around and see the flicker.

I have provided a save file on Eviternity.wad that demonstrates the bug right away. https://my.mixtape.moe/fmqbge.zds

Here's a handy video demonstration