Thank you! :) I will look into this ASAP.

I tried to have a look yesterday, but I didn’t really understand what I was doing. It seems to come from the if ($choice === $givenChoice) in ChoiceList::getValuesForChoices() and ChoiceList::getIndicesForChoices(), but if I change anything it breaks a lot of tests.

I first tried overriding fixChoice and fixChoices to call createValue on the choice, but it breaks tests. Then I tried calling createValue on both sides of the comparison in getValuesForChoices and getIndicesForChoices (overriding them), but in the tests, createValue throws a lot of exceptions for NULL arguments, one might need to check against that too, but what to return?

A side effect of the same issue is that the objects given in $preferredChoices also have to be the same instance to be taken into account.

I took some effort on this issue. It seemed to me that the problem is the comparison for equality in ChoiceList.

Overriding the getValuesForChoices() method in ObjectChoiceList like this fixed the problem for me (note the use of createValue()):

public function getValuesForChoices(array $choices)
{
    $choices = $this->fixChoices($choices);
    $values = array();

    $availableValues = $this->getValues();
    foreach ($this->getChoices() as $i => $choice) {
        foreach ($choices as $j => $givenChoice) {
            if ($this->createValue($choice) === $this->createValue($givenChoice)) {
                $values[] = $availableValues[$i];
                unset($choices[$j]);

                if (0 === count($choices)) {
                    break 2;
                }
            }
        }
    }

    return $values;
}

But I am not so familiar with the internals of the Form component. Thus, I'm not quite sure if this is a general solution. What do you think, @bschussek?

@bschussek should I create a pull request for this?

👍, same issue here, I agree that, if, at least, a valuePath is given, it should compare on the actual value instead of comparing the (reference of) the objects.

+1, I am having the same issue. I hope this pull request passes and gets pulled in.