Link titles are broken when using a non-t callback

Our check did not count on the case that you might use a non-t callback so

if (!$link_translate || (!empty($item['title']) && ($item['title'] == $item['link_title']))) {

needs a change to

if (!$link_translate || ( ( !empty($item['title']) || $item['title_callback'] != 't' ) && ($item['title'] == $item['link_title']))) {

however this can be simplified because the only case ( !empty($item['title']) || $item['title_callback'] != 't' ) is FALSE when nor the title nor the title callback is specified in hook_menu (and because of that the default t is used) and that's broken code http://drupal.org/node/140311 does not list this as a valid case. So we can drop it and get the simple

if (!$link_translate || ($item['title'] == $item['link_title'])) {

code.

D7 patch and test is forthcoming but as this affects d.o. sprint I am inclined to ask for an exception and get it into D6 quick.