Sending HTML + text emails : content-type line appears to the 2nd recipient

[liberio]

Swift Mailer module is unavailable because I use Form Tools 1.5.1...
The issue comes from ft_send_email() function located in global/code/emails.php. Here is the code I modified to correct the bug:

PHP Code:

// ADVANCED emails (email templates)
else
{
    $headers_completed = false;

    // loop through each client assigned to this form, and generate an email for them
    for ($i=0; $i<count($user_info); $i++)
    {
        $client_placeholders = _ft_get_placeholder_hash($form_id, $submission_id, $user_info[$i]);
        switch ($email_template)
        {
            case "both":
                $text_content = _ft_parse_template($form_info["{$email_type}_text_email_template"], $client_placeholders);
                $HTML_content = _ft_parse_template($form_info["{$email_type}_html_email_template"], $client_placeholders, true);
                if (!$headers_completed) 
                    $headers .= _ft_get_multipart_message($HTML_content, $text_content, $eol);
                break;

            case "text":
                $message = _ft_parse_template($form_info["{$email_type}_text_email_template"], $client_placeholders);
                if (!$headers_completed) 
                    $headers .= "Content-type: text/plain; charset=UTF-8";
                break;

            case "html":
                $message = _ft_parse_template($form_info["{$email_type}_html_email_template"], $client_placeholders, true);
                if (!$headers_completed) 
                    $headers .= "Content-type: text/html; charset=UTF-8";
                break;
        }

        $headers_completed = true;

        // only send an email to this client if they have an actual email address specified and
        if (!empty($user_info[$i]['email']) && $clients_may_manage_submission[$user_info[$i]["user_id"]])
            $email_info[] = array($user_info[$i]['email'], $subject, $message, $headers);

        // if required, send an additional email to the site administrator (but NEVER when just testing)
        if (empty($override_recipient) && $email_type == "admin" && $form_info['include_admin_email'] == "yes")
            $email_info[] = array($settings['administrator_email'], $subject, $message, $headers);
    }
} 


Do this patch seems correct to you ?

Steps to reproduce:
Create a form -> Create 2 clients -> Add the 2 clients to the form -> In Emails tab check "Send email notifications to clients for form submissions" -> Select "Text & HTML" emails format(s) -> Select "Full form submission" for client Text and HTML templates -> Update -> Fill in the form and send a submission