Moving files in answer->feedback when moving questions

the answer->feedback is not included in the file moving process

for example
in multichoice/questiontype.php
function find_file_links($question, $courseid){
$urls = array();
// find links in the answers table.
$urls += question_find_file_links_from_html($question->options->correctfeedback, $courseid);
$urls += question_find_file_links_from_html($question->options->partiallycorrectfeedback, $courseid);
$urls += question_find_file_links_from_html($question->options->incorrectfeedback, $courseid);
foreach ($question->options->answers as $answer)

{ $urls += question_find_file_links_from_html($answer->answer, $courseid); }

//set all the values of the array to the question id
if ($urls)

{ $urls = array_combine(array_keys($urls), array_fill(0, count($urls), array($question->id))); }

$urls = array_merge_recursive($urls, parent::find_file_links($question, $courseid));
return $urls;
}

should be modified by something like

foreach ($question->options->answers as $answer)

{ $urls += question_find_file_links_from_html($answer->answer, $courseid); $urls += question_find_file_links_from_html($answer->feedback, $courseid); }

and similarly in function replace_file_links()