Staging Files: Unstage All does not work

Was working on the new stage/unstage area. Need double-click to stage a file, making me click 'Stage Selected' is not ideal.

But when I staged a few files and then wanted to unstage them I clicked 'Unstage All' and nothing happened. I selected each file individually and 'Unstage selected' did the right thing.

Drag and drop could also be good here but double click and space bar functionality would be ideal.