Comment 4 for bug 755548

From mvo's code review on the fix for this bug (only allow single selection on the tree): Setting only single selection "is not ideal as the code supports multiple selection and its actually a quite useful feature IMO. It does not work with the "space" key very well, so we would either need to find a way to make "space" on multiple selections clear the selection and do nothing else (so that the second space triggers the action). Or make the space trigger the best possible action on all selection."