Tests the effect of using the update script on the theme system.
function testThemeSystem() {
// Since visiting update.php triggers a rebuild of the theme system from an
// unusual maintenance mode environment, we check that this rebuild did not
// put any incorrect information about the themes into the database.
$original_theme_data = config('system.theme')
->get('enabled');
$this
->drupalLogin($this->update_user);
$this
->drupalGet($this->update_url, array(
'external' => TRUE,
));
$final_theme_data = config('system.theme')
->get('enabled');
$this
->assertEqual($original_theme_data, $final_theme_data, 'Visiting update.php does not alter the information about themes stored in the database.');
}