Slime size bug

If you spawn a slime like this:

/summon Slime ~ ~ ~ {Size:1000,CustomName:RenameMe,CustomNameVisible:1,Riding:{id:Minecart}}

Minecraft first won't execute commands and later crash:

java.lang.OutOfMemoryError: Java heap space
	at java.util.Arrays.copyOf(Unknown Source)
	at java.util.ArrayList.grow(Unknown Source)
	at java.util.ArrayList.ensureCapacityInternal(Unknown Source)
	at java.util.ArrayList.add(Unknown Source)
	at avu.a(SourceFile:24)
	at afo.a(SourceFile:583)
	at afo.a(SourceFile:578)
	at adg.a(SourceFile:951)
	at oh.d(SourceFile:489)
	at pb.e(SourceFile:1071)
	at pb.e(SourceFile:1339)
	at pc.e(SourceFile:295)
	at pb.h(SourceFile:1194)
	at pc.h(SourceFile:171)
	at us.h(SourceFile:83)
	at oh.Y(SourceFile:1169)
	at pb.Y(SourceFile:1368)
	at adg.a(SourceFile:1359)
	at kn.a(SourceFile:477)
	at adg.g(SourceFile:1339)
	at adg.a(SourceFile:1398)
	at kn.a(SourceFile:477)
	at adg.g(SourceFile:1339)
	at adg.h(SourceFile:1246)
	at kn.h(SourceFile:362)
	at net.minecraft.server.MinecraftServer.u(SourceFile:476)
	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 java.util.Arrays.copyOf(Unknown Source)
	at java.util.ArrayList.grow(Unknown Source)
	at java.util.ArrayList.ensureCapacityInternal(Unknown Source)
	at java.util.ArrayList.add(Unknown Source)
	at avu.a(SourceFile:24)
	at afo.a(SourceFile:583)
	at afo.a(SourceFile:578)
	at adg.a(SourceFile:951)
	at oh.d(SourceFile:489)
	at pb.e(SourceFile:1071)
	at pb.e(SourceFile:1339)
	at pc.e(SourceFile:295)
	at pb.h(SourceFile:1194)
	at pc.h(SourceFile:171)
	at us.h(SourceFile:83)
	at oh.Y(SourceFile:1169)
	at pb.Y(SourceFile:1368)
	at adg.a(SourceFile:1359)
	at kn.a(SourceFile:477)
	at adg.g(SourceFile:1339)
	at adg.a(SourceFile:1398)
	at kn.a(SourceFile:477)
	at adg.g(SourceFile:1339)

-- Entity being ticked --
Details:
	Entity Type: MinecartRideable (ty)
	Entity ID: 393580
	Entity Name: entity.MinecartRideable.name
	Entity's Exact location: 236,48, 164,31, 120,55
	Entity's Block location: World: (236,164,120), Chunk: (at 12,10,8 in 14,7; contains blocks 224,0,112 to 239,255,127), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Entity's Momentum: -0,02, -0,04, 0,04
Stacktrace:
	at adg.h(SourceFile:1246)
	at kn.h(SourceFile:362)

-- Affected level --
Details:
	Level name: Welt
	All players: 1 total; [kq['Marcono1234'/276537, l='Welt', x=236,62, y=164,36, z=120,25]]
	Chunk stats: ServerChunkCache: 5375 Drop: 0
	Level seed: 3115167003074485029
	Level generator: ID 03 - amplified, ver 0. Features enabled: true
	Level generator options: 
	Level spawn location: World: (248,64,116), Chunk: (at 8,4,4 in 15,7; contains blocks 240,0,112 to 255,255,127), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 79291 game time, 79291 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 78977 (now: false), thunder time: 97349 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.u(SourceFile:476)
	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 7 (amd64) version 6.1
	Java Version: 1.7.0_04, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 81838192 bytes (78 MB) / 990445568 bytes (944 MB) up to 990445568 bytes (944 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 1823230 (102100880 bytes; 97 MB) allocated, 1823230 (102100880 bytes; 97 MB) used
	IntCache: cache: 1, tcache: 1, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 994 (55664 bytes; 0 MB) allocated, 777 (43512 bytes; 0 MB) used
	Player Count: 1 / 8; [kq['Marcono1234'/276537, l='Welt', x=236,62, y=164,36, z=120,25]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.