Resolving issues with unknown working parent
In repair.strip (http://selenic.com/hg/file/15afda349b11/mercurial/repair.py#l212), if an exception is thrown, try applying the temp backup bundle.
- Make 'hg recover' be able to recover from an unknown working parent state, maybe by landing you on the branch tip.
- Inside unknown working parent warnings, suggest using 'hg summary', which in turn should suggest using 'hg recover'.