def test_extract_change_topdir_already_correct(self):
    src = os.path.join(self.tmp, "src")
    os.mkdir(src)
    a_dir = os.path.join(src, "a")
    os.mkdir(a_dir)
    tar_gz = qibuild.archive.zip_unix(a_dir)
    dest = os.path.join(self.tmp, "dest")
    qibuild.archive.extract(tar_gz, dest, topdir="a")
    ls_r = qibuild.sh.ls_r(dest)
    self.assertEquals(ls_r, ["a/"])