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What I want to happen is, if a user makes a comment, it will add the comment to the post (obviously) and then modify the post_modified column of the post in the wp_posts table to the time that the comment was posted. Essentially it will make wordpress much more like a forum.

I have been looking around in wp-comments-post.php and query.php but I have not found anything. I assume that it probably isn’t that complicated to do. Can someone help me out here?