'add to group' profile setting doesn't work unless group is set to 'public listings & groups'

Previously you could get a profile to add someone to any group when they filled out the profile by selecting it on the settings of that profile. In 3.4.4 that no longer works unless the group is set to 'public' which has other implications.

We have applied the attached patch to our site to get it going - not sure it's the best approach