bug(?) with Linkin dialog configuration

[pablolivares]

With the "Show and edit join table attributes" option, we have a problem displaying the attributes.

If we select the parent layer "Troncon" and go to the dialog to establish links with child layer "Ligne_offre", the attributes of the parent layer do not always match. Apparently, in the intermediate table "link_troncon_ligne_offre" it's always displayed the first parent entity that's linked to the child entity

To be clear I give an example. As we see in the image below, when we choose the first Troncon that's linked to "Lajoux-lajoux" child entity, in this case Troncon ID 374, and we go to the link manager dialog, we can see that it's ok, the ID of Troncon it's the same.

But if we chose a second Troncon that's linked to "Lajoux-lajoux" child entity, Troncon ID 375 for example, and we go to the link manager dialog, we can see that it's still displayed the first Troncon 374.

I've tested with others tables and it's the same

You can check the model example here
Transports_publics_TEST.zip