Game crashes when I play around with piston heads

I was playing around with the /setblock command in singleplayer. I entered in "/setblock ~ ~ ~ minecraft:piston_head". I don't remember what damage value I entered in. Just keep going up in the damage values and it'll spawn an invisible block at your position that has a weird hitbox. I was about to break it when my game crashed. The crash report is this:

---- Minecraft Crash Report ----
// Hi. I'm Minecraft, and I'm a crashaholic.

Time: 9/28/13 4:44 PM
Description: Ticking memory connection

java.lang.ArrayIndexOutOfBoundsException: 6
	at alp.a(SourceFile:40)
	at kr.d(SourceFile:171)
	at kr.b(SourceFile:198)
	at kr.a(SourceFile:110)
	at kv.a(SourceFile:330)
	at gz.a(SourceFile:46)
	at eb.b(SourceFile:63)
	at kv.e(SourceFile:69)
	at ky.b(SourceFile:40)
	at box.b(SourceFile:83)
	at net.minecraft.server.MinecraftServer.u(SourceFile:494)
	at net.minecraft.server.MinecraftServer.t(SourceFile:411)
	at bou.t(SourceFile:121)
	at net.minecraft.server.MinecraftServer.run(SourceFile:346)
	at jc.run(SourceFile:582)


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

-- Head --
Stacktrace:
	at alp.a(SourceFile:40)
	at kr.d(SourceFile:171)
	at kr.b(SourceFile:198)
	at kr.a(SourceFile:110)
	at kv.a(SourceFile:330)
	at gz.a(SourceFile:46)
	at eb.b(SourceFile:63)
	at kv.e(SourceFile:69)

-- Ticking connection --
Details:
	Connection: kv@52d418a6
Stacktrace:
	at ky.b(SourceFile:40)
	at box.b(SourceFile:83)
	at net.minecraft.server.MinecraftServer.u(SourceFile:494)
	at net.minecraft.server.MinecraftServer.t(SourceFile:411)
	at bou.t(SourceFile:121)
	at net.minecraft.server.MinecraftServer.run(SourceFile:346)
	at jc.run(SourceFile:582)

-- System Details --
Details:
	Minecraft Version: 13w39b
	Operating System: Windows 8 (amd64) version 6.2
	Java Version: 1.8.0-ea, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 222227424 bytes (211 MB) / 449314816 bytes (428 MB) up to 954728448 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 577 (32312 bytes; 0 MB) allocated, 272 (15232 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 70 (3920 bytes; 0 MB) allocated, 48 (2688 bytes; 0 MB) used
	Player Count: 1 / 8; [kq['KylieKoopaVG'/209, l='§4§l§k= §c§lSuperflat §4§l§k=', x=-73.68, y=4.00, z=61.56]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.