http://mercurial.selenic.com/bts/issue1089

  $ hg init

  $ mkdir a

  $ echo a > a/b

  $ hg ci -Am m

  adding a/b

  $ hg rm a

  removing a/b

  $ hg ci -m m a

  $ mkdir a b

  $ echo a > a/b

  $ hg ci -Am m

  adding a/b

  $ hg rm a

  removing a/b

  $ cd b

Relative delete:

  $ hg ci -m m ../a