I wrote a plugin "Silence is Golden Guard" which creates empty index.php file at the folders where it is absent and has an "redirect to blog root" option. It puts
directive into .htaccess file also.
If I put such index.php file as
<br /> <?php<br /> // This file was created automatically by Silence is Golden Guard plugin<br /> header("Location: http://www.shinephp.com");<br /> ?><br />
to the /wp-super-cache/plugins/ folder any call to blog root URL or /wp-admin/ ends with browser error, e.g. for FireFox "Firefox has detected that the server is redirecting the request for this address in a way that will never complete."
Is that normal behaviour for your WP Super Cache plugin? Or it could be resolved?
As a temporal decision I check if the '/wp-super-cache/plugins/' folder exists and WPSC is active, then I put just empty index.php file into /wp-super-cache/plugins/ without redirection directive.