convert: properly pass null ids through .hgtags (issue4678)
Mercurial uses tags of null to mark deletions, but convert was
silently discarding these because it had no mapping for them. Thus, it
was resurrecting deleted tags.
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing:
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.