No proper error handling in validateUpload of Isotope/Widget/MediaManager

[chberger]

I'm facing an issue where I cannot upload product pictures. Even in the system log I can't find any hint pointing to the root cause. The only thing I'm getting is a CRITICAL: Uncaught PHP Exception ErrorException which tells me that the Isotope\Widget\MediaManager class tries to access an array at an undefined position:

[2023-06-24T11:36:47.450658+02:00] request.CRITICAL: Uncaught PHP Exception ErrorException: "Warning: Undefined array key 0" at /var/www/vhosts/#########/shop/vendor/isotope/isotope-core/system/modules/isotope/library/Isotope/Widget/MediaManager.php line 174 {"exception":"[object] (ErrorException(code: 0): Warning: Undefined array key 0 at /var/www/vhosts/#########//shop/vendor/isotope/isotope-core/system/modules/isotope/library/Isotope/Widget/MediaManager.php:174)"} []

The relevant implementation part looks like this:

        $varInput = '';

        try {
            $varInput = $objUploader->uploadTo($uploadFolder);
        } catch (\Exception $e) {
            $this->addError($e->getMessage());
        }

        if ($objUploader->hasError()) {
            $messages = System::getContainer()->get('session')->getFlashBag()->peek('contao_be_error');

            if (\is_array($messages)) {
                foreach ($messages as $strError) {
                    $this->addError($strError);
                }
            }
        }

        Message::reset();

        if (!\is_array($varInput) || empty($varInput)) {
            $this->addError($GLOBALS['TL_LANG']['MSC']['mmUnknownError']);
        }

        return $varInput[0];
    }

I guess in my case the $varInput isn't an array cause something goes wrong in $varInput = $objUploader->uploadTo($uploadFolder);. Thus it shows that generic error message defined by $GLOBALS['TL_LANG']['MSC']['mmUnknownError']. However, after that the code still tries to access the first position of $varInput which is obviously not working.

Overall, I guess it would be helpful if that caught exception would be logged somehow. Otherwise I have no chance to identify the root cause at all.

Contao: 4.13.25
Isotope: 2.8.14
PHP: 8.1.19

[chberger]

Ok, I've investigated it further. The Contao\Messages are not being propagated properly, because this line is not working anymore:

$messages = System::getContainer()->get('session')->getFlashBag()->peek('contao_be_error');

Based on the contao core code, this should be like:

$messages = System::getContainer()->get('request_stack')->getSession()->getFlashBag()->get('contao.BE.error');

After that, the error messages defined in $objUploader->uploadTo($uploadFolder) pop up at the backend (frontend) as expected.

Anyway, I guess you should still handle that array access in the return statement though.

[aschempp]

Sounds related to #2472