TYPO3 Core

Hi,

following the official documentation ( [[https://docs.typo3.org/c/typo3/cms-form/master/en-us/I/Concepts/FormPlugin/Index.html#translation-of-form-plugin]] ) to translate the form plugin in backend, I set my YAML configuration like this :

TYPO3:
  CMS:
    Form:
      prototypes:
        standard:
          formEngine:
            translationFiles:
              # custom translation file
              20: 'EXT:my_site_package/Resources/Private/Language/Database.xlf'

But this file is never used.

I found in Form TranslationService (line 191 for version 10.4) that the translationFiles array is not replaced by a key-descending-sorted array (returned value from "sortArrayWithIntegerKeysDescending" method)

$this->sortArrayWithIntegerKeysDescending($translationFiles);

The translationFiles array remains the same, so the XLIFF file from the Form extension (at index 10) takes precedence over additional custom ones.

A fix could be :

$translationFiles = $this->sortArrayWithIntegerKeysDescending($translationFiles);

Note : version 11 is affected too.