The duplicate button in the layer dock duplicates the selected layer, but the duplicate layer is unusable. Brushes won't work on the canvas and as you can see in the attached image, I can't convert it to a paint layer (like you would a clone) or change it in any way. The original layer is fine.

Reproducible: Always

Steps to Reproduce:
1. select a layer (preferably with something on it)
2. press the duplicate button on the layer dock
3. select the duplicate layer and attempt to paint
Actual Results:  
The duplicate layer is entirely unusable.

Expected Results:  
Duplicated the layer and then allowed me to edit it as I would the original.