Small bug in file processing in form handler

[Dodger77]

Q	A
Bug?	yes
New Feature?	no
Bundle Version	2.5.4
Sulu Version	2.5.20
Browser Version	n/a

Actual Behavior

In

SuluFormBundle/Form/Handler.php

Line 257 in 12d2df1

private function uploadMedia(FormInterface $form, FormConfigurationInterface $configuration): array

there is a bug, that prevents the use of an own upload/attachment field type without the multiple option, so it is necessary to prevent multiple file uploads (e.g. by use of JavaScript).

The part

            if (!\count($formField->getData())) {
                continue;
            }

leads to the error:

count(): Argument #1 ($value) must be of type Countable|array, Symfony\Component\HttpFoundation\File\UploadedFile given

Expected Behavior

I think the intention of the code a few lines later

            if (!\is_array($files)) {
                $files = [$files];
            }

is to generate an array containing a single UploadedFile object. But that cannot be achieved because of the count before.

Steps to Reproduce

Using a custom file upload field type (by overwriting the AttachmentType throughservice decoration or compiler pass) without the multiple option.

Possible Solutions

            if (!$formField->getData() instanceof UploadedFile && !\count($formField->getData())) {
                continue;
            }