Trying to report this bug via the launcher only gives a popup that "we're sorry", and it's only related to spigot servers (I assume).
Can't find any relevant bugs reported allready, so I'll file this one.

Imo even if the server sends non-conforming data, the client shouldn't crash.

---- Minecraft Crash Report ----
// Don't do that.

Time: 6/3/14 7:03 PM
Description: Unexpected error

java.lang.NullPointerException: Unexpected error
at bab.d(SourceFile:169)
at bln.a(SourceFile:1167)
at id.a(SourceFile:99)
at id.a(SourceFile:13)
at ej.a(SourceFile:174)
at blq.e(SourceFile:212)
at ban.p(SourceFile:1306)
at ban.ak(SourceFile:774)
at ban.f(SourceFile:728)
at net.minecraft.client.main.Main.main(SourceFile:148)

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

– Head –
Stacktrace:
at bab.d(SourceFile:169)
at bln.a(SourceFile:1167)
at id.a(SourceFile:99)
at id.a(SourceFile:13)
at ej.a(SourceFile:174)
at blq.e(SourceFile:212)

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [blw['AzaTht'/138652, l='MpServer', x=8.50, y=66.62, z=8.50]]
Chunk stats: MultiplayerChunkCache: 0, 0
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (8,64,8), Chunk: (at 8,4,8 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: 0 game time, 0 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: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 1 total; [blw['AzaTht'/138652, l='MpServer', x=8.50, y=66.62, z=8.50]]
Retry entities: 0 total; []
Server brand: Spigot
Server type: Non-integrated multiplayer server
Stacktrace:
at blr.a(SourceFile:289)
at ban.b(SourceFile:1972)
at ban.f(SourceFile:742)
at net.minecraft.client.main.Main.main(SourceFile:148)

– System Details –
Details:
Minecraft Version: 1.7.9
Operating System: Linux (amd64) version 3.11-2-amd64
Java Version: 1.7.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 122580024 bytes (116 MB) / 275251200 bytes (262 MB) up to 3817865216 bytes (3641 MB)
JVM Flags: 1 total; -Xmx4G
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.7.9
LWJGL: 2.9.1
OpenGL: GeForce GTS 450/PCIe/SSE2 GL version 4.4.0 NVIDIA 331.20, NVIDIA Corporation
GL Caps: Using GL 1.3 multitexturing.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Anisotropic filtering is supported and maximum anisotropy is 16.
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 (UK)
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Anisotropic Filtering: On (16)