wp_notify_postauthor From: problem and pluggable behavior problem

[dglingren]

My application uses the "Email me whenever anyone posts a comment" feature in the Discussion Settings sub panel. I have found two issues with the default WordPress implementation of this feature.

First, WordPress puts an invalid e-mail address in the "From:" header of all messages. In wp-includes/pluggable.php, function wp_notify_postauthor, line 1072 reads:

$wp_email = 'wordpress@' . preg_replace('#^www\.#', '', strtolower($_SERVER['SERVER_NAME']));

This means that the "From" field on all comment notification e-mails will contain an invalid domain name, which causes some SMTP servers to reject the transmission. A fix is to use the comment author's e-mail address when it is available:

if ( '' != $comment->comment_author_email )
  $wp_email = $comment->comment_author_email;
else
  $wp_email = 'wordpress@' . preg_replace('#^www\.#', '', strtolower($_SERVER['SERVER_NAME']));

There are some old (2005) tickets on this issue (e.g., #2053, #1593, #1532), and Changeset 3214 comes close. However, the fix proposed here brings the "From:" address into line with the "Reply-To:" address and is a better fix when the comment_author_email is set.

Second, in my application a notification must be issued even when an author comments on their own post; this is not allowed by the default WordPress implementation. Lines 1015 - 1025 in function wp_notify_postauthor reject the author's comments and moderations.
Since wp_notify_postauthor is a pluggable function, I can change this behavior by implementing my own function and replacing the default.

However, there is also a redundant test of post authorship in wp-includes/comment.php, function wp_new_comment, around lines 1344 - 1348. This means that my custom wp_notify_postauthor is never called. My specific problem can be solved by commenting out a line of code:

// $post = &get_post($commentdata['comment_post_ID']); // Don't notify if it's your own comment

A real fix for this problem should move all of the user_id validation rules out of wp_new_comment and put them in wp_notify_postauthor where they can be modified as needed.