There's a lot of legend and lore surrounding this bug which I would like to clear up. For instance, it wasn't present in the European (PAL) release of the original game that was published on February 20, 2004.
It was fixed back then, and the recent PC port is based on the latest code they had. They also improved many other things; including performance, out of map skips and monster spawn points. That's why speed-runners like the original USA version (NTSC) better, because the PAL version is so well rounded that they can't use many of the original collision defects to parkour and skip half of the game by diving into the skybox. One person's bug might be another person's feature. :)
TL;DR: Yes, it is patched.