Hello.
Please excuse me for any ortography lack that I may have, English is not my mother tonge.
The bug I'd like to report creates lots of floating, no-clipping spider jockeys when I get close enaugh to the spider spawner, and chicken jockeys when I'm close to the zombie spawner. Both of them don't stop creating mobs, even if I cover all six sides of the spawner with torches.

When i first encountered a wave of zombies coming my way in a cave I expected to just fight them all and then lit some torches, and everything will be over.

What actually happened was that when I came close enaugh to the zombie spawner some chicken jockeys appeared and atacked me. Then, when I came across a spider spawner, and went close enaugh to trigger the bug, various spiderless spider jockeys spawned in front of me. They didn't attacked me or anything, they just floated in the air, or traversed the ground while standing still. In the attached pictures you can see what happed better that what I can discribe. No matter how mach torches I lit, or even if I set the dificulty to peacefull, they just keep spawning.

I'm not entirely shure how to trigger the bug, as I haven't been able to reproduce it in other worlds, anyway, I'll do my best.
The next steps are, as far as I know, how I triggered the bug:
1. I came across a naturally generated spider / zombie spawner.
2. I went about ten blocks of distance to trigger the bug.
3. I placed torches on every side of the spawner.
4. The spawner started spawning jockeys.