Currently In place translation support menu title and body fields.

But when you have 2 languages (lang1 and lang2) and from lang1 you set a menu link title to your content, it's saved for menu title of the translation node into lang2 only. Users can be lost.

Fo exemple you dont' have such problem with book outline. The book outline is taken into account only for the current langage and it's OK.

How to correct at least a menu link title taken into account for the current langage or adding menu link title in place translation ?