Code review comment for lp:~dimitern/juju-core/001-upgrade-charm-filter-restart-watchers

On reflection, as discussed online, too much magic. I recommend a
WantAllRelationsEvents method for clarity's sake.

https://codereview.appspot.com/7373046/diff/3001/worker/uniter/filter.go
File worker/uniter/filter.go (right):

https://codereview.appspot.com/7373046/diff/3001/worker/uniter/filter.go#newcode226
worker/uniter/filter.go:226: return relationsw.Err()
I think this bit is equivalent to "if ok {return nil}". Don't you need:

if !ok {
   if err := relationsw.Err(); err != nil {
     return err
   }
   relationsw = f.service.WatchRelations()
}

https://codereview.appspot.com/7373046/