[MC-12545] Certain "stacked" riding mob spawners crash the game

An Enderdragon riding another mob. Sounds insane, but someone had to try it eventually. It doesn't even have to successfully spawn or be in range - just the spawner existing in a loaded chunk will cause the crash. I've tried it with a Skeleton and with a Ghast, to the same result.

Attachments

crash-2013-03-21_17.12.54-client.txt

Spawner Test.rar

Spawner Test.zip

Comments 20

Tails 2013-03-21T21:10:05Z

Please attach the crash report, otherwise this ticket is incomplete.

otherhand 2013-03-21T21:15:23Z

I apologize, all fixed now.

Tails 2013-03-21T21:19:05Z

Note:

Description: Ticking entity
java.lang.NullPointerException
	at mp.x(SourceFile:281)
	at mp.l_(SourceFile:277)
	at qt.c(SourceFile:257)
	at ng.l_(SourceFile:551)
	at mp.T(SourceFile:1138)
	at ng.T(SourceFile:498)

Anon Ymus 2013-03-21T22:40:30Z

Can you attach the world?

otherhand 2013-03-21T23:32:18Z

Added world containing offending spawner

10 more comments

Anon Ymus 2013-03-21T23:37:25Z

Sorry to bother you, but is it possible to attach it as a zip file instead?

otherhand 2013-03-21T23:40:59Z

No problem, hope this helps.

Anon Ymus 2013-03-21T23:51:28Z

Crash confirmed in 1.5.1.

Anon Ymus 2013-03-21T23:58:21Z

Moving the spawner farther away allowed it to appear in the loaded chunks without a crash, but as soon as I got within about 50 blocks, the boss life bar appeared at the top of the screen and the same crash happened.

FireHunterX 2013-03-22T00:02:47Z

I'm going to go ahead and say it, but doing stupid stuff does come with consequences, as stated in the report about the world generated with only Fire. It was never meant to be for a reason.

otherhand 2013-03-30T00:46:25Z

For makers of adventure maps and other such creations, this isn't a stupid useless thing. Other mobs could be used to "corral" the dragon and keep it from just flying away or wreaking havoc. You could even put one on a minecart track.

Tails 2013-05-10T22:16:24Z

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

otherhand 2013-05-11T00:39:53Z

Tested the same world as above, confirmed unchanged in 13w19a. The issue is still present.

Jesper the End 2013-05-11T14:37:26Z

Your world is crashing my game indeed. But I managed to spawn riding entities in a spawner. And that one is not crashing. I think you're doing something wrong/different. When I'm spawning riding entities a ghost entity is spawned. But that's exactly what I want. I want to recreate a 'frozen game' in wich nothing is moving.

otherhand 2013-05-11T17:05:02Z

What order did you stack them in?

Jesper the End 2013-05-11T17:23:18Z

Villager in minecart (just by pushing it towards the villager)
Villager on villager
Minecart on villager
Boat on ender dragon
And maybe another one but I can't remember

Jesper the End 2013-10-15T20:32:21Z

your world doesn't crash my game any more in 13w41b

galaxy_2alex 2014-01-22T14:17:49Z

Is this still a concern in the current Minecraft version 1.7.4 / Launcher version 1.3.8 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Also, is it even possible to create a stack spawner without a 3rd party program? If yes, please post the reproduction steps here.

Itouch2 2014-03-09T12:30:34Z

The world doesn't crash my game either, in 1.7.5

Jesper the End 2014-05-11T14:33:03Z

This bug is fixed, you can a mod close it?