Client relation handling doesn't do back-relations anymore

[luisa-beerboom]

It used to be that if one followed a relation field in a subscription, the contra-relation would automatically be filled for the other viewModel as well.

I.e. if one subscribed to a meeting and followed the motion_ids, the ViewMeeting would have a field motions with all of the corresponding ViewMotions and the corresponding ViewMotions would all have a field meeting that was filled with the ViewMeeting in question.

It seems like that has somehow stopped happening.
There have recently been multiple bugs that were caused because a subscription followed a field, but the counter-relation wasn't named anywhere in the fieldset, causing the connection to either not be built, or only be built one-way (I'm not quite sure which).
An example of this would be #2710 which could not be fixed without adding the back-relation for the meeting-users user_id field into the fieldset of the follow.

[bastianjoel]

I was not able to find anything that looks like doing something like that. I mainly looked for this in the datastore related services and model request handling.

[bastianjoel]

There is actually an issue very specific to meeting users where this does not work.
Retrieving the meeting user for a given meeting is implemented in the repo very specifically. For that reason I think this is not problem in general.