In a Drupal 6 (core) forum, when I post something, I can afterwards edit it, unless someone replies on my post creating a thread. In that case the option to edit my original post does not appear at all.
Can I override this behavior? I'd like to be able to edit my posts/comments where ever they appear, even inside a thread.
This is checked in http://api.drupal.org/api/drupal/modules--comment--comment.module/function/comment_access/6, it looks like that check has been removed in D7 (the documentation hasn't been updated to reflect that, though).
I guess you could implement hook_links on your own and then add the link yourself. See http://api.drupal.org/api/drupal/modules--comment--comment.module/function/comment_links/6.
The more complicated one to override will probably be http://api.drupal.org/api/drupal/modules--comment--comment.pages.inc/function/comment_edit/6, you could use hook_menu_alter probably.