Following an IRC discussion (
http://irclog.perlgeek.de/darcs/2012-03-13#i_5283168 ), and the fact
that the "unknown" annotation can appear also with files when annotating
directories ( see issue2154 ), I would suggest Owen roll backs this
patch, and that we try to tackle the root of this problem. That is,
seeing to it that all lines always end up annotated at the moment we
reach the patch that added a given file.