Extract some email address utility code from the receiver stack

Summary:
Ref T7477. We have some address normalization code in the reciever stack that is really shared code. I want to introduce some new callsites elsewhere but don't want to put a lot of static calls to other random objects all over the place.

This technically "solves" T7477 (it changes "to" to "to + cc" for finding receivers) but doesn't yet implement proper behavior (with multiple receivers, for example).

Test Plan: Ran unit tests, which cover this pretty well. Additional changes will vet this more thoroughly.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T7477

Differential Revision: https://secure.phabricator.com/D19948

src/__phutil_library_map__.php

@@ -3408,6 +3408,7 @@ phutil_register_library_map(array(
     'PhabricatorMailRoutingRule' => 'applications/metamta/constants/PhabricatorMailRoutingRule.php',
     'PhabricatorMailStamp' => 'applications/metamta/stamp/PhabricatorMailStamp.php',
     'PhabricatorMailTarget' => 'applications/metamta/replyhandler/PhabricatorMailTarget.php',
+    'PhabricatorMailUtil' => 'applications/metamta/util/PhabricatorMailUtil.php',
     'PhabricatorMainMenuBarExtension' => 'view/page/menu/PhabricatorMainMenuBarExtension.php',
     'PhabricatorMainMenuSearchView' => 'view/page/menu/PhabricatorMainMenuSearchView.php',
     'PhabricatorMainMenuView' => 'view/page/menu/PhabricatorMainMenuView.php',
@@ -9215,6 +9216,7 @@ phutil_register_library_map(array(
     'PhabricatorMailRoutingRule' => 'Phobject',
     'PhabricatorMailStamp' => 'Phobject',
     'PhabricatorMailTarget' => 'Phobject',
+    'PhabricatorMailUtil' => 'Phobject',
     'PhabricatorMainMenuBarExtension' => 'Phobject',
     'PhabricatorMainMenuSearchView' => 'AphrontView',
     'PhabricatorMainMenuView' => 'AphrontView',

src/applications/metamta/receiver/PhabricatorMailReceiver.php

@@ -25,10 +25,10 @@ abstract class PhabricatorMailReceiver extends Phobject {
       ->withApplicationPHIDs(array($app->getPHID()))
       ->execute();
 
-    foreach ($mail->getToAddresses() as $to_address) {
+    foreach ($mail->newTargetAddresses() as $address) {
       foreach ($application_emails as $application_email) {
-        $create_address = $application_email->getAddress();
-        if ($this->matchAddresses($create_address, $to_address)) {
+        $create_address = $application_email->newAddress();
+        if (PhabricatorMailUtil::matchAddresses($create_address, $address)) {
           $this->setApplicationEmail($application_email);
           return true;
         }
@@ -194,66 +194,6 @@ abstract class PhabricatorMailReceiver extends Phobject {
       $reasons);
   }
 
-  /**
-   * Determine if two inbound email addresses are effectively identical. This
-   * method strips and normalizes addresses so that equivalent variations are
-   * correctly detected as identical. For example, these addresses are all
-   * considered to match one another:
-   *
-   *   "Abraham Lincoln" <alincoln@example.com>
-   *   alincoln@example.com
-   *   <ALincoln@example.com>
-   *   "Abraham" <phabricator+ALINCOLN@EXAMPLE.COM> # With configured prefix.
-   *
-   * @param   string  Email address.
-   * @param   string  Another email address.
-   * @return  bool    True if addresses match.
-   */
-  public static function matchAddresses($u, $v) {
-    $u = self::getRawAddress($u);
-    $v = self::getRawAddress($v);
-
-    $u = self::stripMailboxPrefix($u);
-    $v = self::stripMailboxPrefix($v);
-
-    return ($u === $v);
-  }
-
-
-  /**
-   * Strip a global mailbox prefix from an address if it is present. Phabricator
-   * can be configured to prepend a prefix to all reply addresses, which can
-   * make forwarding rules easier to write. A prefix looks like:
-   *
-   *  example@phabricator.example.com              # No Prefix
-   *  phabricator+example@phabricator.example.com  # Prefix "phabricator"
-   *
-   * @param   string  Email address, possibly with a mailbox prefix.
-   * @return  string  Email address with any prefix stripped.
-   */
-  public static function stripMailboxPrefix($address) {
-    $address = id(new PhutilEmailAddress($address))->getAddress();
-
-    $prefix_key = 'metamta.single-reply-handler-prefix';
-    $prefix = PhabricatorEnv::getEnvConfig($prefix_key);
-
-    $len = strlen($prefix);
-
-    if ($len) {
-      $prefix = $prefix.'+';
-      $len = $len + 1;
-    }
-
-    if ($len) {
-      if (!strncasecmp($address, $prefix, $len)) {
-        $address = substr($address, strlen($prefix));
-      }
-    }
-
-    return $address;
-  }
-
-
   /**
    * Reduce an email address to its canonical form. For example, an address
    * like:

src/applications/metamta/receiver/PhabricatorObjectMailReceiver.php

@@ -150,7 +150,7 @@ abstract class PhabricatorObjectMailReceiver extends PhabricatorMailReceiver {
   private function matchObjectAddressInMail(
     PhabricatorMetaMTAReceivedMail $mail) {
 
-    foreach ($mail->getToAddresses() as $address) {
+    foreach ($mail->newTargetAddresses() as $address) {
       $parts = $this->matchObjectAddress($address);
       if ($parts) {
         return $parts;
@@ -160,12 +160,11 @@ abstract class PhabricatorObjectMailReceiver extends PhabricatorMailReceiver {
     return null;
   }
 
-  private function matchObjectAddress($address) {
+  private function matchObjectAddress(PhutilEmailAddress $address) {
+    $address = PhabricatorMailUtil::normalizeAddress($address);
+    $local = $address->getLocalPart();
+
     $regexp = $this->getAddressRegexp();
-
-    $address = self::stripMailboxPrefix($address);
-    $local = id(new PhutilEmailAddress($address))->getLocalPart();
-
     $matches = null;
     if (!preg_match($regexp, $local, $matches)) {
       return false;

src/applications/metamta/receiver/__tests__/PhabricatorMailReceiverTestCase.php

@@ -17,7 +17,9 @@ final class PhabricatorMailReceiverTestCase extends PhabricatorTestCase {
 
     foreach ($same as $address) {
       $this->assertTrue(
-        PhabricatorMailReceiver::matchAddresses($base, $address),
+        PhabricatorMailUtil::matchAddresses(
+          new PhutilEmailAddress($base),
+          new PhutilEmailAddress($address)),
         pht('Address %s', $address));
     }
 
@@ -32,7 +34,9 @@ final class PhabricatorMailReceiverTestCase extends PhabricatorTestCase {
 
     foreach ($diff as $address) {
       $this->assertFalse(
-        PhabricatorMailReceiver::matchAddresses($base, $address),
+        PhabricatorMailUtil::matchAddresses(
+          new PhutilEmailAddress($base),
+          new PhutilEmailAddress($address)),
         pht('Address: %s', $address));
     }
   }

src/applications/metamta/storage/PhabricatorMetaMTAApplicationEmail.php

@@ -88,6 +88,10 @@ final class PhabricatorMetaMTAApplicationEmail
     return $message;
   }
 
+  public function newAddress() {
+    return new PhutilEmailAddress($this->getAddress());
+  }
+
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
 

src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php

@@ -82,6 +82,27 @@ final class PhabricatorMetaMTAReceivedMail extends PhabricatorMetaMTADAO {
     return $this->getRawEmailAddresses(idx($this->headers, 'to'));
   }
 
+  public function newTargetAddresses() {
+    $raw_addresses = array();
+
+    foreach ($this->getToAddresses() as $raw_address) {
+      $raw_addresses[] = $raw_address;
+    }
+
+    foreach ($this->getCCAddresses() as $raw_address) {
+      $raw_addresses[] = $raw_address;
+    }
+
+    $raw_addresses = array_unique($raw_addresses);
+
+    $addresses = array();
+    foreach ($raw_addresses as $raw_address) {
+      $addresses[] = new PhutilEmailAddress($raw_address);
+    }
+
+    return $addresses;
+  }
+
   public function loadAllRecipientPHIDs() {
     $addresses = array_merge(
       $this->getToAddresses(),

src/applications/metamta/util/PhabricatorMailUtil.php

@@ -0,0 +1,65 @@
+<?php
+
+final class PhabricatorMailUtil
+  extends Phobject {
+
+  /**
+   * Normalize an email address for comparison or lookup.
+   *
+   * Phabricator can be configured to prepend a prefix to all reply addresses,
+   * which can make forwarding rules easier to write. This method strips the
+   * prefix if it is present, and normalizes casing and whitespace.
+   *
+   * @param PhutilEmailAddress Email address.
+   * @return PhutilEmailAddress Normalized address.
+   */
+  public static function normalizeAddress(PhutilEmailAddress $address) {
+    $raw_address = $address->getAddress();
+    $raw_address = phutil_utf8_strtolower($raw_address);
+    $raw_address = trim($raw_address);
+
+    // If a mailbox prefix is configured and present, strip it off.
+    $prefix_key = 'metamta.single-reply-handler-prefix';
+    $prefix = PhabricatorEnv::getEnvConfig($prefix_key);
+    $len = strlen($prefix);
+
+    if ($len) {
+      $prefix = $prefix.'+';
+      $len = $len + 1;
+
+      if (!strncasecmp($raw_address, $prefix, $len)) {
+        $raw_address = substr($raw_address, $len);
+      }
+    }
+
+    return id(clone $address)
+      ->setAddress($raw_address);
+  }
+
+  /**
+   * Determine if two inbound email addresses are effectively identical.
+   *
+   * This method strips and normalizes addresses so that equivalent variations
+   * are correctly detected as identical. For example, these addresses are all
+   * considered to match one another:
+   *
+   *   "Abraham Lincoln" <alincoln@example.com>
+   *   alincoln@example.com
+   *   <ALincoln@example.com>
+   *   "Abraham" <phabricator+ALINCOLN@EXAMPLE.COM> # With configured prefix.
+   *
+   * @param   PhutilEmailAddress Email address.
+   * @param   PhutilEmailAddress Another email address.
+   * @return  bool True if addresses are effectively the same address.
+   */
+  public static function matchAddresses(
+    PhutilEmailAddress $u,
+    PhutilEmailAddress $v) {
+
+    $u = self::normalizeAddress($u);
+    $v = self::normalizeAddress($v);
+
+    return ($u->getAddress() === $v->getAddress());
+  }
+
+}