Redmine

We add several plugins to redmine code base and start running tests. Since some plugins intentionally break vanilla redmine logic a couple of tests fails. It looks confusing.
To avoid that failures we patched redmine to skip tests if specific plugins are loaded. Unfortunately it does not work for functional tests, because of this piece of code: test/functional/admin_controller_test.rb:105

  def test_no_plugins
    Redmine::Plugin.clear

    get :plugins
    assert_response :success
    assert_template 'plugins'
  end

The method Redmine::Plugin.clear looks suspicious: it clears hash of installing plugins without really unloading them. Plugin is loaded but every other class believes it does not.

It is a defect or behaviour by design?