Doom barrel bug strikes again.

[neubejiita]

Hello Doomworld. I was playing the No End In sight beta release on E1M8 and a Baron destroyed a barrel and hurt a Demon, resulting in the Demon attacking the Baron. Later on as shown in this screenshot below, I ended up with a Baron attacking another Baron due to another barrel bug. Is the barrel bug very common these days? I was using prboom 2.5.0 with the Doom complevel settings configured in the menus.

http://www.securitronlinux.com/files/doom02.png

http://www.doomworld.com/vb/wads-mods/60012-the-ultimate-doom-no-end-in-sight-beta-release/

[Rizera]

Up to the latest versions of Doom 1 and 2 (1.9), if a monster destroys a barrel and hurt another one, this hurt one will try to kill the one who destroyed the barrel even if they are of the same species. By barrel destroying, you can see some very unusual fights like Cacodemon vs Cacodemon, Revenant vs Revenant and even Mancubus vs Mancubus.

[Memfis]

Here is a cool map by Espi based on this bug: http://www.doomworld.com/idgames/index.php?id=10749

[Maes]

The condition for starting an infighting is also quite more restrictive than people believe: if a "healthy" barrel is destroyed in a single hit, then no "barrel destroyer" is registered, and no weird infighting starts. In order for it to happen, a barrel must first be damaged little enough as to NOT blow up, and then when it blows up, the "blame" goes to the one who damaged it last without blowing it up.

In other words, it's possible to blow up a barrel and have someone else "take the blame" ;-) This is a bug due to how the barrel handling code works: an attacker is registered only if the barrel survives a hit from that attacker, and the barrel passes on this "attacker information" to its victims, if not null.

This is also why "barrel chain infighting" usually doesn't work in vanilla Doom and other ports than don't modify this behavior: barrels in a chain all blow up in a single hit, and no "transmission of blame" is possible. Some ports alter this behavior so it's possible to "transmit blame" down such chains.

[eargosedown]

Memfis said:

Here is a cool map by Espi based on this bug: http://www.doomworld.com/idgames/index.php?id=10749

That was pretty fun actually

[Ledmeister]

If anyone's interested, here's some examples of the barrel bug in v1.9 vanilla Doom games:
Imps fight each other
Baron fight
Cacodemon fight 1, 2
Revenant fight in Final Doom

And some examples of an earlier version of the bug, where monsters can even attack themselves:
http://www.youtube.com/playlist?list=PLEC0372C361BD8FDE

[yellowmadness54]

I believe it also causes monsters to fight themselves.

[eargosedown]

yellowmadness54 said:

I believe it also causes monsters to fight themselves.

In earlier versions, it did. That bug was fixed though.

[The Green Herring]

And to add one more to the pile, here's an example used in a max run (first level shown).

Excuse the heinously bad quality of the WAD (which I comment on in more detail in the video description), but this goes to show it does come in handy sometimes!