TYPO3 Core

In the file MediaContentObject.php Line 299 and Line 301 there are the sanity checks missing, which will trigger an PHP warning, which will produce an error.

https://typo3.org/api/typo3cms/_media_content_object_8php_source.html#l00299
https://typo3.org/api/typo3cms/_media_content_object_8php_source.html#l00301

The function explanation itself tells it will lookup the keys and if not present will use the defaults. <https://typo3.org/api/typo3cms/class_t_y_p_o3_1_1_c_m_s_1_1_frontend_1_1_content_object_1_1_media_content_object.html#a680af7dc67ac0db3435f864aea3f05e5>

But it does not really checks for presence. It just assumes.

Original:

  295       protected function doFlexFormOverlay(array &$confArray, $key, $sectionKey = NULL) {
  296                 $flexValue = NULL;
  297                 $flexKey = 'mm' . ucfirst($key);
  298                 if ($sectionKey === NULL) {
  299                         $flexValue = $confArray['parameter.'][$flexKey];
  300                 } else {
  301                         $flexValue = $confArray['parameter.'][$flexKey][$sectionKey];
  302                 }
  303                 if ($flexValue === NULL) {
  304                         $flexValue = isset($confArray[$key . '.']) ? $this->cObj->stdWrap($confArray[$key], $confArray[$key . '.']) : $confArray[$key];
  305                 }
  306                 return $flexValue;
  307         }
  308

        protected function doFlexFormOverlay(array &$confArray, $key, $sectionKey = NULL) {
                $flexValue = NULL;
                $flexKey = 'mm' . ucfirst($key);
                if ($sectionKey === NULL) {
                        if (is_array($confArray['parameter.']))
                                $flexValue = $confArray['parameter.'][$flexKey];
                } else {
                        if (is_array($confArray['parameter.']) && is_array($flexValue = $confArray['parameter.'][$flexKey]))
                                $flexValue = $confArray['parameter.'][$flexKey][$sectionKey];
                }
                if ($flexValue === NULL) {
                        $flexValue = isset($confArray[$key . '.']) ? $this->cObj->stdWrap($confArray[$key], $confArray[$key . '.']) : $confArray[$key];
                }
                return $flexValue;
        }