Hopper bug with duping

*What I expected to happen was normal transportation like it was supposed to do and it did but more...

*What actually happened was It gave me more than enough to be rich with unlimited stuff.

Steps to Reproduce:
1. Throw anything even enchanted stuff in the hopper it will double it
2. It doubles anything put in it
3. If you throw a stack of something in the corner of it. it makes unlimited of the items in hopper.