[MC-82873] Cannot get property on Rails

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-2526969/

Crash:

java.lang.IllegalArgumentException: Cannot get property any{name=shape, clazz=class agf$b, values=[north_south, east_west, ascending_east, ascending_west, ascending_north, ascending_south, south_east, south_west, north_west, north_east]} as it does not exist in anm{block=minecraft:golden_rail, properties=[powered, shape]}
	at anm$a.b(SourceFile:132)
	at agf$a.<init>(SourceFile:49)
	at agf$a.b(SourceFile:120)
	at agf$a.c(SourceFile:102)
	at agf$a.d(SourceFile:234)
	at agf$a.a(SourceFile:245)
	at agf.a(SourceFile:468)
	at akg.b(SourceFile:22)
	at agf.a(SourceFile:457)

The following is the first clean report made public about this crash:

---- Minecraft Crash Report ----
// My bad.

Time: 7/29/15 9:50 AM
Description: Exception while updating neighbours

java.lang.IllegalArgumentException: Cannot get property any{name=shape, clazz=class agf$b, values=[north_south, east_west, ascending_east, ascending_west, ascending_north, ascending_south, south_east, south_west, north_west, north_east]} as it does not exist in anm{block=minecraft:golden_rail, properties=[powered, shape]}
	at anm$a.b(SourceFile:132)
	at agf$a.<init>(SourceFile:49)
	at agf$a.b(SourceFile:120)
	at agf$a.c(SourceFile:102)
	at agf$a.d(SourceFile:234)
	at agf$a.a(SourceFile:245)
	at agf.a(SourceFile:468)
	at akg.b(SourceFile:22)
	at agf.a(SourceFile:457)
	at aen.d(SourceFile:428)
	at aen.c(SourceFile:395)
	at akm.c(SourceFile:76)
	at aok.a(SourceFile:551)
	at aen.a(SourceFile:291)
	at akm.b(SourceFile:139)
	at lg.a(SourceFile:527)
	at lg.d(SourceFile:199)
	at net.minecraft.server.MinecraftServer.B(SourceFile:599)
	at net.minecraft.server.MinecraftServer.A(SourceFile:535)
	at bsg.A(SourceFile:152)
	at net.minecraft.server.MinecraftServer.run(SourceFile:451)
	at java.lang.Thread.run(Thread.java:745)


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

-- Head --
Stacktrace:
	at anm$a.b(SourceFile:132)
	at agf$a.<init>(SourceFile:49)
	at agf$a.b(SourceFile:120)
	at agf$a.c(SourceFile:102)
	at agf$a.d(SourceFile:234)
	at agf$a.a(SourceFile:245)
	at agf.a(SourceFile:468)
	at akg.b(SourceFile:22)
	at agf.a(SourceFile:457)

-- Block being updated --
Details:
	Source block type: ID #76 (tile.notGate // akm)
	Block: minecraft:rail[shape=south_west]
	Block location: World: (-158,17,270), Chunk: (at 2,1,14 in -10,16; contains blocks -160,0,256 to -145,255,271), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Stacktrace:
	at aen.d(SourceFile:428)
	at aen.c(SourceFile:395)
	at akm.c(SourceFile:76)
	at aok.a(SourceFile:551)
	at aen.a(SourceFile:291)
	at akm.b(SourceFile:139)

-- Block being ticked --
Details:
	Block: minecraft:unlit_redstone_torch[facing=up]
	Block location: World: (-158,15,270), Chunk: (at 2,0,14 in -10,16; contains blocks -160,0,256 to -145,255,271), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Stacktrace:
	at lg.a(SourceFile:527)
	at lg.d(SourceFile:199)

-- Affected level --
Details:
	Level name: party
	All players: 1 total; [lh['footyspleefking'/48, l='party', x=-79.37, y=13.00, z=243.45]]
	Chunk stats: ServerChunkCache: 798 Drop: 0
	Level seed: -3319104331395916414
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: 75.00,74.00,204.00 - World: (75,74,204), Chunk: (at 11,4,12 in 4,12; contains blocks 64,0,192 to 79,255,207), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 7646809 game time, 204219 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 1 (now: false), thunder time: 1 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.B(SourceFile:599)
	at net.minecraft.server.MinecraftServer.A(SourceFile:535)
	at bsg.A(SourceFile:152)
	at net.minecraft.server.MinecraftServer.run(SourceFile:451)
	at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
	Minecraft Version: 15w31a
	Operating System: Windows 8.1 (amd64) version 6.3
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 109309728 bytes (104 MB) / 300736512 bytes (286 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 61, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [lh['footyspleefking'/48, l='party', x=-79.37, y=13.00, z=243.45]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.