Implements hook_language_insert().
function field_language_insert() {
field_info_cache_clear();
// If the number of languages is bigger than 1, enable the core language
// fallback rules.
// Because the language_count is updated only after the hook is invoked, we
// check if the language_count is bigger or equal with 1 at the current time.
if (variable_get('language_count', 1) >= 1) {
variable_set('field_language_fallback', TRUE);
}
}