When you're inline editing entities, the language of the parent entity is to be respected.
1) if you're editing an english node, newly added products also have "english" set as their language.
2) If you're using Entity Translation and adding a french translation for the node, then the product values should be saved under "fr" as well.
(Assuming ET is enabled for both entity types).
#1 has been fixed in
Related issue in the ET issue queue: .
Right now IEF doesn't care about the product language (doesn't touch it if it's set, sets it to LANGUAGE_NONE if it isn't).
It should care, showing and editing the products in the language of the parent entity.
So if the widget is shown on the french translation of a parent entity (node translation or entity translation, irrelevant), then it should manipulate the french values of the child entity fields.
Of course, it should work for any entity type (inline and parent). That's why we need entity_language() to land in D7 core.
Postponed on the D7 core issue:and the entity_translation issue: (since it's a big patch that would require us to retest and probably rework pieces).