Can't add your dataset to my group

At present, I can't add a dataset to my group unless I have edit rights to the dataset. I should be able to add any dataset.

This should  be done via "Add dataset" on the group home page. At the moment this goes to the dataset creation page, but this is the wrong behaviour, since creating datasets has nothing to do with groups.

Group page > Add dataset should just give a box where I can start typing a dataset name, choose a suggested completion, and hit "add" or "remove".