Puting an item in any type of horse's inventory besides a donkey crashes the game.

Please include the crash report.

I duplicated this glitch and here is the crash report:

---- Minecraft Crash Report ----
// I let you down. Sorry :(

Time: 20/08/14 04:42
Description: Updating screen events

java.lang.ArrayIndexOutOfBoundsException: 2
	at wa.a(SourceFile:115)
	at ajh.d(SourceFile:81)
	at ahy.a(SourceFile:239)
	at ceh.a(SourceFile:368)
	at byg.a(SourceFile:515)
	at byg.b(SourceFile:486)
	at bxa.k(SourceFile:411)
	at bxa.p(SourceFile:382)
	at bsr.r(SourceFile:1478)
	at bsr.as(SourceFile:876)
	at bsr.a(SourceFile:313)
	at net.minecraft.client.main.Main.main(SourceFile:120)


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

-- Head --
Stacktrace:
	at wa.a(SourceFile:115)
	at ajh.d(SourceFile:81)
	at ahy.a(SourceFile:239)
	at ceh.a(SourceFile:368)
	at byg.a(SourceFile:515)
	at byg.b(SourceFile:486)
	at bxa.k(SourceFile:411)
	at bxa.p(SourceFile:382)

-- Affected screen --
Details:
	Screen name: bzd

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [cij['WelshyRhys'/20, l='MpServer', x=-749.56, y=56.85, z=-531.84]]
	Chunk stats: MultiplayerChunkCache: 225, 225
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: -755.00,4.00,-517.00 - World: (-755,4,-517), Chunk: (at 13,0,11 in -48,-33; contains blocks -768,0,-528 to -753,255,-513), Region: (-2,-2; contains chunks -64,-64 to -33,-33, blocks -1024,0,-1024 to -513,255,-513)
	Level time: 197299 game time, 3043 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 34 total; [adt['item.item.dyePowder.black'/4294796, l='MpServer', x=-745.19, y=58.00, z=-543.31], adt['item.item.dyePowder.black'/448896, l='MpServer', x=-744.75, y=56.00, z=-538.69], adt['item.item.dyePowder.black'/4294797, l='MpServer', x=-743.97, y=56.00, z=-541.66], abn['Bat'/3794504, l='MpServer', x=-747.41, y=54.10, z=-573.34], adt['item.item.dyePowder.black'/4, l='MpServer', x=-756.06, y=58.00, z=-538.19], adt['item.item.dyePowder.black'/678882, l='MpServer', x=-745.28, y=58.00, z=-539.78], abn['Bat'/3928038, l='MpServer', x=-710.47, y=50.10, z=-500.72], adt['item.item.dyePowder.black'/10, l='MpServer', x=-746.25, y=58.00, z=-545.25], adt['item.item.dyePowder.black'/11, l='MpServer', x=-745.81, y=58.00, z=-544.13], adt['item.item.dyePowder.black'/3966007, l='MpServer', x=-745.00, y=56.00, z=-542.16], adt['item.item.dyePowder.black'/2224019, l='MpServer', x=-757.00, y=58.00, z=-542.16], adt['item.item.dyePowder.black'/13, l='MpServer', x=-745.19, y=56.00, z=-544.25], adt['item.item.dyePowder.black'/14, l='MpServer', x=-744.00, y=56.00, z=-544.44], adt['item.tile.cloth.green'/2669428, l='MpServer', x=-743.13, y=57.00, z=-552.69], adt['item.item.dyePowder.black'/16, l='MpServer', x=-748.00, y=58.00, z=-538.13], adt['item.item.dyePowder.black'/4456475, l='MpServer', x=-755.94, y=58.00, z=-541.19], adt['item.item.dyePowder.black'/1163231, l='MpServer', x=-745.16, y=58.00, z=-539.00], cij['WelshyRhys'/20, l='MpServer', x=0.54, y=-158.68, z=0.45], adt['item.item.dyePowder.black'/4456476, l='MpServer', x=-756.97, y=58.00, z=-539.59], adt['item.item.dyePowder.black'/4348242, l='MpServer', x=-754.84, y=60.00, z=-539.03], adt['item.item.dyePowder.black'/2444338, l='MpServer', x=-755.13, y=58.00, z=-540.75], adt['item.item.dyePowder.black'/4348243, l='MpServer', x=-753.91, y=60.00, z=-539.38], abs['Horse'/3774578, l='MpServer', x=-749.56, y=56.00, z=-531.84], cij['WelshyRhys'/20, l='MpServer', x=-749.56, y=56.85, z=-531.84], adt['item.item.dyePowder.black'/933053, l='MpServer', x=-745.00, y=58.00, z=-544.22], adt['item.item.dyePowder.black'/3769423, l='MpServer', x=-755.13, y=58.00, z=-545.53], adt['item.item.dyePowder.black'/774626, l='MpServer', x=-754.97, y=58.00, z=-542.13], adt['item.item.dyePowder.black'/2657133, l='MpServer', x=-756.97, y=58.00, z=-545.09], adt['item.item.dyePowder.black'/1314646, l='MpServer', x=-755.94, y=58.00, z=-540.25], adt['item.item.dyePowder.black'/860393, l='MpServer', x=-755.91, y=58.00, z=-545.25], adt['item.item.dyePowder.black'/3643300, l='MpServer', x=-746.88, y=60.00, z=-541.75], adt['item.item.dyePowder.black'/340368, l='MpServer', x=-747.38, y=60.00, z=-539.63], adt['item.item.dyePowder.black'/3687353, l='MpServer', x=-755.50, y=57.00, z=-544.31], adt['item.item.dyePowder.black'/469204, l='MpServer', x=-753.66, y=60.00, z=-544.06]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at cei.a(SourceFile:308)
	at bsr.b(SourceFile:2257)
	at bsr.a(SourceFile:322)
	at net.minecraft.client.main.Main.main(SourceFile:120)

-- System Details --
Details:
	Minecraft Version: 14w34c
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_65, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 172093496 bytes (164 MB) / 311091200 bytes (296 MB) up to 523501568 bytes (499 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 14w34c
	LWJGL: 2.9.1
	OpenGL: GeForce GT 420/PCIe/SSE2 GL version 4.4.0, NVIDIA Corporation
	GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

	Using VBOs: No
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: []
	Current Language: English (US)
	Profiler Position: N/A (disabled)

Confirmed in 1.8-pre2 (attached crash report "crash-2014-08-28_01.09.08client").
(BTW in the /entitydata command you forgot to add a space b/w the ] and { 🙂 ).

You are not allowed to place chests on a non mule/donkey, as any other type of horse is not set up to support/handle it.

What are the forced entities supposed to be under the crash report and why does black dye appear so many times?

My guess for the black dye is that he recently did /kill @e[type=Squid] ?
Also yeah, horse types other than donkeys/mules aren't coded to have inventories, so when you try to put something in the inventory the game tries to save the item to a non-existent part of the horse's data.

Also @Sonicwave that's just due to the way this site formats newlines; it removes spaces and puts a newline instead, however when copying and pasting, it removes the newline for some reason, but there is no space there anymore either.

Dupe of MC-16234