function i18n_preprocess_page in Internationalization 6
Implementation of hook_preprocess_page().
Add the language code to the classes for the <body> tag. Unfortunately, some themes will not respect the variable we're modifying to achieve this - in particular, Garland and Minelli do not.
File
- ./i18n.module, line 528 
- Internationalization (i18n) module.
Code
function i18n_preprocess_page(&$variables) {
  if (isset($variables['body_classes'])) {
    global $language;
    $variables['body_classes'] .= ' i18n-' . $language->language;
  }
}