drush-ops/drush — pull request #885 by tstoeckler (2014-10-16 08:19:38+00:00)
Title: Prevent Drush scanning the root directory

By accidentally adding '/' as a commandfile searchpath in
_drush_find_commandfiles() Drush ends up scanning the entire directory tree.
This can happen if drupal_get_filename() returns NULL, which can happen in
very rare circumstances, for example if a module is registered as installed in
the configuration but does not exist in the filesystem.