tests/test-dirstate-backup.t

directaccess: fix uses of commands.status() that don't go through flag parsing

When `commands.commit.post-status` is enabled, after commit/amend,
commands.status() is called without any revs argument, which means that status
gets None instead of an empty list like it would receive if the user had invoked
this on the commandline. With the `experimental.directaccess` config enabled,
this gets passed to `unhidehashlikerevs`, which didn't previously handle None,
but now should.

Differential Revision: https://phab.mercurial-scm.org/D11883

Set up

  $ hg init repo
  $ cd repo

Try to import an empty patch

  $ hg import --no-commit - <<EOF
  > EOF
  applying patch from stdin
  abort: stdin: no diffs found
  [10]

No dirstate backups are left behind

  $ ls .hg/dirstate* | sort
  .hg/dirstate