drupal_get_install_files returns contrib/custom modules

This issue occurs when additional modules have been added to sites/all/modules before installing Drupal. The install path is /install.php?profile=default&locale=en

The regexp in drupal_get_install_files matches too many files:
drupal_system_listing($module .'.install$', 'modules')

If there are other modules available that happen to end with $module, e.g. admin_menu and menu, they will get loaded by drupal_check_profile() and hook_requirements called.

This causes errors if the module uses parts of the API that are loaded at module install time, but which aren't available at Drupal install time.