Mime Type Problem when Uploading DOC, DOCX, ODT Files in Symfony

If you create a DOC file with OpenOffice, its mimetype will be application/octet-stream, that can be anything binary data. Of course, you can't allow this mimetype at uploading.

If you try to upload DOCX and ODT files, symfony will recognise them as a ZIP archive. To corrrect this and the OpenOffice DOC mimetype problem, add the 'mime_type_guessers' option to sfValidatorFile:

$this->setValidator('filename', new sfValidatorFile(array(
      'max_size' => ...,
      'path' => ...,
      'mime_type_guessers' => array('guessFromFileinfo'),
      'required' => ...,
      ...