OU wiki: 'Create page' appears for visible groups when you don't have access (OU 11056)

Create a 'group' wiki with visible groups.

Visit wiki as student. Change group to a group that isn't yours. There is a
'Create page' button (although if you click it you get a 'permission denied'
error). This button should not be present because you don't have access to
create pages in somebody else's group