You are able to add compostable material with compost still in bin.
Description of issue
You are able to add items like weeds and pineapples to compost bins while the bin still has some compost in it. You will obtain the remainder of the last batch of compost when removing the compost and then it will start converting your buckets to the compostable item you put in with the remaining compost.
What should have happened
You should not be able to add to the compost bin while it still has compost inside.
Reproduction steps (if applicable)
Add a compostable item to the bin while it still has compost in it and then remove it. Watch your buckets turn into the items you added to the bin. (tested on test server)