I found a way to hijack the comment before it’s attached to its post in the DB. Using the snippet below you can attach every comment to your dummy post. Just change COMMENT_ID
to the ID of your dummy post. No hacking of core needed!
<?php
add_filter('preprocess_comment', 'akt_hijack_comment');
function akt_hijack_comment($comment) {
define('AKT_REDIRECT_URL', $comment['comment_post_ID']);
$comment['comment_post_ID'] = 63;
return $comment;
}
add_filter('comment_post_redirect', 'akt_redirect');
function akt_redirect($location) {
return get_permalink(AKT_REDIRECT_URL);
}
A side-effect that I haven’t tried fixing yet: after submission of the comment, the user is redirected to the dummy post. Not sure if I’ll have time to figure it out tonight.
I edited the code to redirect the user back to the same page that was commented on.
Edit: You can make this into a plugin (add // Plugin Name: SOME_NAME
under <?php
) or a mu-plugin (paste as into a file and upload it to wp-content/mu-plugins
– create mu-plugins directory if needed). Or you can paste into the functions.php of your theme (least desirable method).