I destroyed, picked up, placed and destroyed a mushroom, and it crashed my Minecraft. This was done on a multiplayer server, the server did not crash
Steps to reproduce:
Destroy and and place the same mushroom in the nether 2-8 times.
Linked issues
Attachments
Comments
Duplicate of MC-7622.

Any reason for an updated LWJGL ?
And your Java version seems to be out of date. Please ensure you have the latest Java version installed for maximum compatibility. You can check your Java version here.

-> Redownload the snapshot.
I updated Java to Java 7 patch 11 and redownloaded the snapshot (both client and server) and the bug still occurs. Updated LWJGL was because I thought the mouse issues (taking items out of crafting) with 13w01b were due to bad LWJGL

Cannot reproduce.
Placed and harvested two stacks of brown mushrooms in the nether - no crash.
Are you really sure that you downloaded the updated snapshot from http://www.mojang.com/ again and that you did copy the fresh downloaded minecraft.jar (or maybe called minecraft(2).jar) to the right place ?
I was able to reproduce the bug 3 times