From 67c302ae4f90d4b100bf049ee6ba9d629e46dfb0 Mon Sep 17 00:00:00 2001
From: Nick Harper <nharper@fb.com>
Date: Tue, 17 Jul 2012 16:50:52 -0700
Subject: [PATCH] Send messages with only a CC

Summary: This keeps people in the correct To or CC field on multiplexed messages.

Test Plan:
with multiplexing on, checked that I received an email with me in the CC
field instead of the To field for a diff I'm CC'd on.

Reviewers: epriestley, jungejason, vrana

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D2999
---
 conf/default.conf.php                          |  6 ++++++
 .../PhabricatorMailReplyHandler.php            | 11 +++++++++--
 .../metamta/storage/PhabricatorMetaMTAMail.php | 18 ++++++++++++------
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/conf/default.conf.php b/conf/default.conf.php
index 29c7b716a3..52d8178b1b 100644
--- a/conf/default.conf.php
+++ b/conf/default.conf.php
@@ -266,6 +266,12 @@ return array(
   // sometimes referred to as "multiplexing".
   'metamta.one-mail-per-recipient'  => true,
 
+  // When sending a message that has no To recipient (i.e. all recipients
+  // are CC'd, for example when multiplexing mail), set the To field to the
+  // following value. If no value is set, messages with no To will have
+  // their CCs upgraded to To.
+  'metamta.placeholder-to-recipient' => null,
+
   // When a user takes an action which generates an email notification (like
   // commenting on a Differential revision), Phabricator can either send that
   // mail "From" the user's email address (like "alincoln@logcabin.com") or
diff --git a/src/applications/metamta/replyhandler/PhabricatorMailReplyHandler.php b/src/applications/metamta/replyhandler/PhabricatorMailReplyHandler.php
index 18a2640f3c..c15057e929 100644
--- a/src/applications/metamta/replyhandler/PhabricatorMailReplyHandler.php
+++ b/src/applications/metamta/replyhandler/PhabricatorMailReplyHandler.php
@@ -142,9 +142,16 @@ abstract class PhabricatorMailReplyHandler {
     $body .= "\n";
     $body .= $this->getRecipientsSummary($to_handles, $cc_handles);
 
-    foreach ($recipients as $recipient) {
+    foreach ($recipients as $phid => $recipient) {
       $mail = clone $mail_template;
-      $mail->addTos(array($recipient->getPHID()));
+      if (isset($to_handles[$phid])) {
+        $mail->addTos(array($phid));
+      } else if (isset($cc_handles[$phid])) {
+        $mail->addCCs(array($phid));
+      } else {
+        // not good - they should be a to or a cc
+        continue;
+      }
 
       $mail->setBody($body);
 
diff --git a/src/applications/metamta/storage/PhabricatorMetaMTAMail.php b/src/applications/metamta/storage/PhabricatorMetaMTAMail.php
index c83b3c9f44..5dae327158 100644
--- a/src/applications/metamta/storage/PhabricatorMetaMTAMail.php
+++ b/src/applications/metamta/storage/PhabricatorMetaMTAMail.php
@@ -606,16 +606,22 @@ final class PhabricatorMetaMTAMail extends PhabricatorMetaMTADAO {
       }
 
 
+      $empty_to =
+        PhabricatorEnv::getEnvConfig('metamta.placeholder-to-recipient');
+      if ($empty_to !== null && !$add_to) {
+        $mailer->addTos(array($empty_to));
+      }
       if ($add_to) {
         $mailer->addTos($add_to);
-        if ($add_cc) {
+      }
+      if ($add_cc) {
+        if ($empty_to !== null) {
           $mailer->addCCs($add_cc);
+        } else {
+          $mailer->addTos($add_cc);
         }
-      } else if ($add_cc) {
-        // If we have CC addresses but no "to" address, promote the CCs to
-        // "to".
-        $mailer->addTos($add_cc);
-      } else {
+      }
+      if (!$add_to && !$add_cc) {
         $this->setStatus(self::STATUS_VOID);
         $this->setMessage(
           "Message has no valid recipients: all To/CC are disabled or ".