Hello fellow Quakers!
After many, many years I've been revisiting my old maps and I've noticed the infamous skybox outlines bug. Is there any way to actually "fix" the skybox and make the outlines disappear? Or any other way how to get rid of them in game?
Only useful thing I've found so far is a mention of a Q3MAP2 parameter in this thread (lvlworld.com/thread/496/0), although I have no idea which parameter this is...
Many thanks in advance!

All the source ports fix it by now as it's texture clamp behavior. It's probably one the most trivial fixes to do in the renderer.

The origin of the bug is that the "gold standard" nVidia did a texture clamping mode wrong in the first place, which gaslit ATI Radeons for having 'buggy opengl drivers' while they were correct the whole time, and Q3's stock skyboxes were dark space skies so id never noticed until much later
Edited 3.12 minutes after the original posting.

Thank you for the detailed answer. It's good to know about the ports. I guess this also means there is no way to fix it in vanilla quake 3?

@RotaryFist.cz : There is a sort of fix you can do, but the sky will need to look different. You can make a patch file a with a shader in like this:

textures/rotary08/rotary08_skybox
{
qer_editorimage env/dragonvale/dragonvale_ft.tga
surfaceparm sky
surfaceparm noimpact
surfaceparm nolightmap
q3map_globaltexture
q3map_lightsubdivide 256
q3map_surfacelight 30
q3map_sun 1 0.9 0.7 200 290 35
skyparms env/dragonvale/dragonvale - -
{
map textures/sfx/firegorre.tga
tcMod scale 2.5 2.5
tcMod scroll 0.015 0.03
rgbGen identityLighting
}
}