drush dl drupalorg_testing --package-handler=git_drupalorg problem when development release = master

I don't know where to submit this issue (drush, drupalorg_testing od git_dev). I assume the git-team would like to know of this problem, because it will affect some other projects as well.

drupalorg_testing (http://drupal.org/project/drupalorg_testing) has only a 6.x-2.x-dev release, based on the master branch.

$ dl -v drupalorg_testing --package-handler=git_drupalorg
Initialized Drupal 6.21-dev root directory at /var/www/mydrupalorg                                                                                   [notice]
Executing: git --version
Downloading release history from http://updates.drupal.org/release-history/drupalorg_testing/6.x                                                     [notice]
Executing: mkdir '/tmp/drush_tmp_1298908492'
Downloading project drupalorg_testing to /tmp/drush_tmp_1298908492 ...                                                                               [notice]
Executing: git clone  git://git.drupal.org/project/drupalorg_testing.git /tmp/drush_tmp_1298908492/drupalorg_testing
Calling chdir(/tmp/drush_tmp_1298908492/drupalorg_testing)
Executing: git checkout  6.x-2.x
Calling chdir(/var/www/mydrupalorg)
Unable to retrieve drupalorg_testing from git.drupal.org.                                                                                         [error]
Error downloading drupalorg_testing

Git tries to checkout the non-existing branch 6.x-2.x.

There are several solutions possible:

• all projects with a -dev version based on master are encouraged to create a 6.x-n.x version and abandon the master branch.
• drush could detect the problem and leaves the project on the master branch, with a warning (dangerous, could be a 7.x-n.x version)

I am not sure if it is still possible to Create a release based on the master branch. If yes, it should be made inpossible.