mq: pop/refresh: avoid losing revisions not managed by mq
We already disallow committing on top of an mq revision exactly
to avoid losing this new revision during a qpop/qrefresh, so this
can be seen as an additional safety check.
If this is not enough to fix
issue844, it should at least prevent
it from happening.
adding a
Now at: a.patch
applying b.patch
applying c.patch
Now at: c.patch
Now at: b.patch