Client crash with Workshop and damaged items

[devryb]

When using an item that takes damage in crafting it will crash your client as soon as it breaks.
Here's an example with making copper cable from copper plates and wire cutters.
As soon as they are on the last craft before breaking it will crash you when you pull the cable out.

http://puu.sh/myEDE/99bcf20080.png

Version: 0.5.1

Crash report: http://pastebin.com/jTZdf9Wh