Please include a PR checklist in the description.

I'm not convinced this is the best approach to solve #9738. Since any missing fields would be ignored and no error would be raised, user might expect that all his choices were saved.

@jakzal Yes, but it would only be used in the case where there might be outdated data. Eg, I am using it on a search form where the options can change quite often. Therefore, I don't want an error to be thrown because the search option chosen no longer exists. I still want the form to search with the options which are now available.

PR checklist has been added.

I see a real issue here: the option is not applied consistently

@stof how do you mean? Do you mean for non expanded etc? This would only apply where the field is expanded and allows multiple options.

why wouldn't it apply for non-expanded fields allowing multiple selection ? there is no difference between expanded and collapsed rendering of the choice fields as far as the submission processing is concerned (the submitted data looks exactly the same in both cases)

Ah, yes it should. Sorry, I will fix up tomorrow morning

@stof that has been updated. Let me know if there is anything else

Hi @trsteel88, thank you for that PR! Unfortunately, #12148 changes quite a bit of the code that is touched by this PR. Hence this needs to be redone when #12148 is merged.