comment edit does not use the post_preview template file when previewing edited comments

The comment edit uses the wrong template file to preview the edited comment.

This is because the offset used in the preprocess function is wrong

  3 /**
  4  * @file
  5  * Holds the contents of a preprocess function moved into its own file
  6  * to ease memory requirements and having too much code in one file.
  7  */
  8 function _advanced_forum_preprocess_comment(&$variables) {
  9   /* Easy links to the comment and parent node */
 10   $comment = $variables['comment'];
 11   $node = node_load($comment->nid);
 12   $variables['first_post'] = $node;
 13
 14   // This is a comment, not the node.
 15   $variables['top_post'] = FALSE;
 16
 17   /* Determine the template file to use for the comment. */
 18   if (arg(1) == 'reply' || arg(1) == 'edit') {
 19     // Use the preview version
 20     advanced_forum_add_template_suggestions("post-preview", $variables);
 21   }
 22   else {
 23     // Use our combined node/comment template file
 24     advanced_forum_add_template_suggestions("post", $variables);
 25   }
 26

arg(1) == 'edit'

should be

arg(2) == 'edit'

I have a custom advanced-forum.MY-CUSTOM-STYLE.post-preview.tpl.php which was not being picked up before the change. It was picked up on reply but not edit.

After the change the custom template was picked up when I edit the comments.