Bottom face of fence with block below turns black (Smooth lighting off)

Cannot confirm.
Please redo the screenshots with default resource pack, please attach a screenshot of your video settings and please force a crash by pressing F3 + C for 10 seconds while in-game and attach the crash report ([minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/finding-minecraft-data-folder]) here.

@Kumasasa Turn off Smooth lighting.

---- Minecraft Crash Report ----
// Sorry :(

Time: 24/06/14 15:11
Description: Manually triggered debug crash

java.lang.Throwable
	at blj.q(SourceFile:1539)
	at blj.ap(SourceFile:861)
	at blj.a(SourceFile:303)
	at net.minecraft.client.main.Main.main(SourceFile:121)


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

-- Head --
Stacktrace:
	at bya.a(SourceFile:310)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [cby['RiJyk94'/54, l='MpServer', x=-1,75, y=64,13, z=16,26]]
	Chunk stats: MultiplayerChunkCache: 289, 289
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: 0,00,4,00,0,00 - World: (0,4,0), Chunk: (at 0,0,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 121025 game time, 5000 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: 21 total; [yn['Bat'/977253, l='MpServer', x=-6,10, y=22,24, z=-30,17], cby['RiJyk94'/54, l='MpServer', x=-1,75, y=64,13, z=16,26], zc['Squid'/791789, l='MpServer', x=10,50, y=61,00, z=-8,86], yn['Bat'/977261, l='MpServer', x=-4,20, y=22,05, z=-27,07], yn['Bat'/452859, l='MpServer', x=-7,59, y=22,97, z=-29,34], yy['Pig'/13, l='MpServer', x=-59,34, y=64,13, z=-58,53], yy['Pig'/14, l='MpServer', x=-53,31, y=64,13, z=-55,84], yy['Pig'/15, l='MpServer', x=-55,50, y=64,13, z=-58,31], yq['Cow'/16, l='MpServer', x=-54,53, y=64,13, z=-56,38], yn['Bat'/809816, l='MpServer', x=-25,56, y=30,09, z=31,72], yq['Cow'/18, l='MpServer', x=-49,94, y=64,00, z=-7,03], yn['Bat'/283285, l='MpServer', x=-47,29, y=32,10, z=83,94], yq['Cow'/24, l='MpServer', x=-45,09, y=64,00, z=-8,16], yq['Cow'/26, l='MpServer', x=-39,81, y=64,00, z=33,19], yq['Cow'/29, l='MpServer', x=-30,38, y=64,00, z=-45,66], yn['Bat'/750783, l='MpServer', x=34,44, y=40,28, z=-55,40], yn['Bat'/34, l='MpServer', x=3,22, y=37,10, z=32,53], yr['Horse'/32, l='MpServer', x=-8,16, y=64,00, z=7,03], yn['Bat'/36, l='MpServer', x=2,47, y=36,10, z=32,53], uu['entity.LeashKnot.name'/53, l='MpServer', x=-6,50, y=65,50, z=7,50], yn['Bat'/919282, l='MpServer', x=-49,39, y=23,11, z=24,20]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bya.a(SourceFile:310)
	at blj.b(SourceFile:2134)
	at blj.a(SourceFile:312)
	at net.minecraft.client.main.Main.main(SourceFile:121)

-- System Details --
Details:
	Minecraft Version: 14w25b
	Operating System: Linux (i386) version 3.11.0-23-generic
	Java Version: 1.6.0_31, Sun Microsystems Inc.
	Java VM Version: OpenJDK Server VM (mixed mode), Sun Microsystems Inc.
	Memory: 109543104 bytes (104 MB) / 554172416 bytes (528 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 1 total; -Xmx1G
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 14w25b
	LWJGL: 2.9.1
	OpenGL: AMD Radeon 6600M and 6700M Series GL version 4.3.12682 Compatibility Profile Context 13.101, ATI Technologies Inc.
	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.

	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)

Ok, thanks.
Confirmed.

Seems to be a dup of/relates to MC-51804 though

Yes, I agree

Yup, same cause.