Implements hook_language_delete().
function field_language_delete() {
field_info_cache_clear();
// If the number of languages is less than 2, disable the core language
// fallback rules.
// Because the language_count is updated after the hook is invoked, we check
// if the language_count is less or equal with 2 at the current time.
if (variable_get('language_count', 1) <= 2) {
variable_set('field_language_fallback', FALSE);
}
}