Stop question editor from automatically adding new answer fields upon re-editing question

Moodle 2.1 file question/type/edit_question_form.php line 323 and sq.

replace

if ($this->question->formoptions->repeatelements) {

    $repeatsatstart = max($minoptions, $countanswers + $addoptions);

} else {

    $repeatsatstart = $countanswers;

}

with

if ($this->question->formoptions->repeatelements) {

    if ($countanswers) {

        $repeatsatstart = $countanswers;

    } else {

        $repeatsatstart = $minoptions;

    }

} else {

    $repeatsatstart = $countanswers;

}

Create a SHORTANSWER question.
Check that the editing interface displays the default number (3) of Answer fields.
Enter data for 2 Answer only.
Save.
Edit that question.
Check that only the 2 Answer fields you entered previously are displayed, with no extra Answer field.
Click the "Blanks for 3 more choices" button
Enter data for Answer 3 only
Save
Edit question again
Check that only the 3 Answer fields you entered previously are displayed, with no extra Answer field.
—
Repeat test with MATCH and MULTICHOICE questions