Extra apostrophes when entering PHP code in a textarea

Whenever I try to use the "Enter PHP Code if true" extra '' are added to my code. For example a simple snippet like:

<?php
global $user;
if (in_array('Approved Role',$user->roles)) {
return TRUE;
} else {
return FALSE;
}
?>

is changed to:

<?php
global $user;
if (in_array(''''Approved Role'''',$user->roles)) {
return TRUE;
} else {
return FALSE;
}
?>

This happens whenever I try to use any PHP snippets - not just with the block visibility settings. I am using a plain text editor.

I've searched the Drupal issues, but didn't find any issues for this or any patch. Help please!