java.lang.RuntimeException: Already decorating

When trying to abuse the /effects command and speed effect, at one point, game crashed on me:

---- Minecraft Crash Report ----
// Quite honestly, I wouldn't worry myself about that.

Time: 6/19/14 11:10 PM
Description: Exception getting block type in world

java.lang.RuntimeException: Already decorating
	at amt.a(SourceFile:25)
	at amm.a(SourceFile:397)
	at amy.a(SourceFile:143)
	at bad.a(SourceFile:482)
	at ot.a(SourceFile:175)
	at ayv.a(SourceFile:1015)
	at ot.c(SourceFile:104)
	at ot.d(SourceFile:117)
	at alu.b(SourceFile:273)
	at alu.f(SourceFile:268)
	at alu.c(SourceFile:204)
	at aqx.c(SourceFile:80)
	at aof.b(SourceFile:642)
	at ou.h(SourceFile:345)
	at ou.c(SourceFile:179)
	at net.minecraft.server.MinecraftServer.w(SourceFile:570)
	at net.minecraft.server.MinecraftServer.v(SourceFile:506)
	at coe.v(SourceFile:132)
	at net.minecraft.server.MinecraftServer.run(SourceFile:422)
	at java.lang.Thread.run(Thread.java:744)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at amt.a(SourceFile:25)
	at amm.a(SourceFile:397)
	at amy.a(SourceFile:143)
	at bad.a(SourceFile:482)
	at ot.a(SourceFile:175)
	at ayv.a(SourceFile:1015)
	at ot.c(SourceFile:104)
	at ot.d(SourceFile:117)
	at alu.b(SourceFile:273)
	at alu.f(SourceFile:268)

-- Requested block coordinates --
Details:
	Found chunk: true
	Location: World: (1969,61,960), Chunk: (at 1,3,0 in 123,60; contains blocks 1968,0,960 to 1983,255,975), Region: (3,1; contains chunks 96,32 to 127,63, blocks 1536,0,512 to 2047,255,1023)
Stacktrace:
	at alu.c(SourceFile:204)
	at aqx.c(SourceFile:80)
	at aof.b(SourceFile:642)
	at ou.h(SourceFile:345)
	at ou.c(SourceFile:179)

-- Affected level --
Details:
	Level name: New World
	All players: 1 total; [ox['AzaTht'/61, l='New World', x=1921.72, y=78.43, z=696.70]]
	Chunk stats: ServerChunkCache: 1566 Drop: 0
	Level seed: -5874701542317078405
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: 173.00,64.00,253.00 - World: (173,64,253), Chunk: (at 13,4,13 in 10,15; contains blocks 160,0,240 to 175,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 16801 game time, 5733 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 78556 (now: false), thunder time: 145166 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.w(SourceFile:570)
	at net.minecraft.server.MinecraftServer.v(SourceFile:506)
	at coe.v(SourceFile:132)
	at net.minecraft.server.MinecraftServer.run(SourceFile:422)
	at java.lang.Thread.run(Thread.java:744)

-- System Details --
Details:
	Minecraft Version: 14w25b
	Operating System: Linux (amd64) version 3.11-2-amd64
	Java Version: 1.7.0_51, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 277891112 bytes (265 MB) / 1146617856 bytes (1093 MB) up to 3817865216 bytes (3641 MB)
	JVM Flags: 1 total; -Xmx4G
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [ox['AzaTht'/61, l='New World', x=1921.72, y=78.43, z=696.70]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.