wp_mail not recognizing cc and bcc headers

Question

I am using WordPress 3.1.3

I am getting following notices when I use wp_mail with cc and bcc headers.

Notice: Undefined variable: cc in /var/www/mysite.info/htdocs/wordpress/wp-includes/pluggable.php on line 349 
Notice: Undefined variable: bcc in /var/www/mysite.info/htdocs/wordpress/wp-includes/pluggable.php on line 352 

This is how I am setting email headers

$email_headers  = "From: ".$from_field_value.PHP_EOL;
$email_headers .= "Reply-To: ".$from_field_value.PHP_EOL;
$email_headers .= "CC: mail@gmail.com".PHP_EOL;
$email_headers .= "BCC: mail@gmail.com".PHP_EOL;

if (wp_mail($email_to, $email_subject, $email_body, $email_headers)) {
      // Other process
}

Answer 1

If you look at the line the notice is being issued:

$cc = array_merge( (array) $cc, explode( ',', $content ) );

and

$bcc = array_merge( (array) $bcc, explode( ',', $content ) );

What its trying to do is merge a blank array that hasn't been set with an array created by your headers.

The notice can be ignored. After all its just a notice.

As this function is pluggable you can copy the function and place in a plugin file and correct the code. That way you are not editing core files. See pluggable functions:

http://codex.wordpress.org/Pluggable_Functions

I would modify the code as follows:

case 'cc':
    if (!isset($cc))
        $cc = array();
    $cc = array_merge( $cc, explode( ',', $content ) );
break;
case 'bcc':
    if (!isset($bcc))
        $bcc = array();
    $bcc = array_merge( $bcc, explode( ',', $content ) );
break;

Maybe this should be reported to wordpress core dev team?

UPDATE:

Above will be fixed in WP3.2 http://core.trac.wordpress.org/changeset/18006