Way of matching user form

[rolintoucour]

Submitting a form that is a collection of elements, the match between the type data and the user data is based on the index of the elements.

In a concurrent edition of a form, it may cause troubles, eg:

• two users open the same form of a collection of 3 elements,
• the first user adds an element and save => successfull,
• the seconds also adds an element => the form handling process matches its fourth element to the first user's added element, instead of detecting it is a new element. Moreover, as no PK has been sent by the second user, his element will be associated to the PK of the first user's element, this PK will be marked as a 'modified column' and propel will try to set the PK and will crash at saving.

The match seems to be based on the element index, instead of the primary key.