Adding group repository to another group repository triggers excessive re-index activity

1. Started with a stock configuration.
2. Enabled index download for central, codehaus snapshots.
3. When this was done published indexes for "public" group.
4. Created new group repository, added "public" as a member.

This triggers a "repair index" task against the new group, which forced all remote indexes for proxy repositories to be downloaded and processed again. Furthermore, for some reason indexes were published for the new group (I didn't ask for this).