[support] Determine if comments have replies

[Cameron B. Prince]

I have a need to determine if comments have replies. This is what I've come
up with to make this determination, but I would rather find a way that
doesn't require an additional database query per comment.

function theme_preprocess_comment(&$variables) {
  $comment = $variables['elements']['#comment'];
  $count = db_query('SELECT COUNT(*) FROM {comment} WHERE pid = :cid',
array(':cid' => $comment->cid))->fetchField();
  $comment->has_children = !empty($count);
}

I can see that theme_preprocess_node has access to the entire array of
comments in its $variables argument when displaying it with print_r. The
issue is I can't seem to figure out how to loop over the comments so that I
could check for a value in the pid field and add a has_children => TRUE to
the parent comment's array.

Can someone point me in the right direction?

Thanks,
cameronbprince