[1.9] Forge Crash

[alittlelage]

On certain servers which give/take away a shield to imitate blocking with a sword on 1.8, Forge 1.9 crashes. I tested this using Forge build 1877 with no mods on the hypixel.net server. To reproduce, join a game (in 1.9) which uses swords (I tested using SkyWars) and right click with a sword in your hand. It may take a couple right clicks to crash the game.

fml-client-latest: http://pastebin.com/pmVEvSb1

 

Edit: Tested again with the new recommended build that came out today, still crashes with the same message.

[LexManos]

Honestly I have no idea how the data watcher and the internal data is is desyncing but things happen on modded servers.

I've pushed a NPE protection in for it. We'll see if people can figure out more information but all of our logic seems sound.

[alittlelage]

I am confirming that the new build fixes the problem.

Thanks, Lex!