[MC-52852] setting negative variable in the /particle effect crashes the game

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here

What actually happened was...:
Describe what happened here

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...

Environment

Put your operating system (Windows 7, Windows XP, OSX) and Java version if you know it here

incomplete

What did I think would happen?
Not sure, present the particle effect in a different way. .. or atleast generate an error saying it was impossible.

What actually happened?
The server crashed.

How to trigger the bug?
Put -1 in the speed field of the particle command

Cannot reproduce in 14w11b or 14w18a

ya this was fixed at some point already. Can be closed.