Code review comment for lp:~aauzi/midori/fix-1179200

> The consequences on the client views are the following:
> 1- they should ignore add_item of katze_array which are not type
> KATZE_TYPE_ITEM
> 2- they should ignore add_item of katze_item of a folder
>

Additional note:

The consequence on client side may be totally removed if midori_bookmarks derives from katze_array and implements the preprocessing of folders (convert in katze_array of type KATZE_ARRAY_ITEM) and the population of the content of a katze_array is done in a specialization of katze_array_add_item.

By doing so we could ensure that *valid* items would be signaled to the client views.