Handle incoming emails from aliases correctly

These set the 'actual' destination email in one of the Delivered-To lines, so
check those too.

changelogs/unreleased/2247-emails-forwarded-to-service-desk-email-don-t-come.yml

+---
+title: Handle incoming emails from aliases correctly
+merge_request:
+author:

lib/gitlab/email/receiver.rb

@@ -57,9 +57,8 @@ module Gitlab
       end
 
       def key_from_additional_headers(mail)
-        references = ensure_references_array(mail.references)
-
-        find_key_from_references(references)
+        find_key_from_references(mail) ||
+          find_key_from_delivered_to_header(mail)
       end
 
       def ensure_references_array(references)
@@ -75,12 +74,19 @@ module Gitlab
         end
       end
 
-      def find_key_from_references(references)
-        references.find do |mail_id|
+      def find_key_from_references(mail)
+        ensure_references_array(mail.references).find do |mail_id|
           key = Gitlab::IncomingEmail.key_from_fallback_message_id(mail_id)
           break key if key
         end
       end
+
+      def find_key_from_delivered_to_header(mail)
+        Array(mail[:delivered_to]).find do |header|
+          key = Gitlab::IncomingEmail.key_from_address(header.value)
+          break key if key
+        end
+      end
     end
   end
 end

spec/fixtures/emails/forwarded_new_issue.eml

+Delivered-To: incoming+gitlabhq/gitlabhq+auth_token@appmail.adventuretime.ooo
+Return-Path: <jake@adventuretime.ooo>
+Received: from iceking.adventuretime.ooo ([unix socket]) by iceking (Cyrus v2.2.13-Debian-2.2.13-19+squeeze3) with LMTPA; Thu, 13 Jun 2013 17:03:50 -0400
+Received: from mail-ie0-x234.google.com (mail-ie0-x234.google.com [IPv6:2607:f8b0:4001:c03::234]) by iceking.adventuretime.ooo (8.14.3/8.14.3/Debian-9.4) with ESMTP id r5DL3nFJ016967 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for <incoming+gitlabhq/gitlabhq@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 17:03:50 -0400
+Received: by mail-ie0-f180.google.com with SMTP id f4so21977375iea.25 for <incoming+gitlabhq/gitlabhq@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 14:03:48 -0700
+Received: by 10.0.0.1 with HTTP; Thu, 13 Jun 2013 14:03:48 -0700
+Date: Thu, 13 Jun 2013 17:03:48 -0400
+From: Jake the Dog <jake@adventuretime.ooo>
+Delivered-To: support@adventuretime.ooo
+To: support@adventuretime.ooo
+Message-ID: <CADkmRc+rNGAGGbV2iE5p918UVy4UyJqVcXRO2=otppgzduJSg@mail.gmail.com>
+Subject: New Issue by email
+Mime-Version: 1.0
+Content-Type: text/plain;
+ charset=ISO-8859-1
+Content-Transfer-Encoding: 7bit
+X-Sieve: CMU Sieve 2.2
+X-Received: by 10.0.0.1 with SMTP id n7mr11234144ipb.85.1371157428600; Thu,
+ 13 Jun 2013 14:03:48 -0700 (PDT)
+X-Scanned-By: MIMEDefang 2.69 on IPv6:2001:470:1d:165::1
+
+The reply by email functionality should be extended to allow creating a new issue by email.
+
+* Allow an admin to specify which project the issue should be created under by checking the sender domain.
+* Possibly allow the use of regular expression matches within the subject/body to specify which project the issue should be created under.

spec/lib/gitlab/email/receiver_spec.rb

@@ -4,6 +4,24 @@ require_relative 'email_shared_blocks'
 describe Gitlab::Email::Receiver, lib: true do
   include_context :email_shared_context
 
+  context "when the email contains a valid email address in a Delivered-To header" do
+    let(:email_raw) { fixture_file('emails/forwarded_new_issue.eml') }
+    let(:handler) { double(:handler) }
+
+    before do
+      stub_incoming_email_setting(enabled: true, address: "incoming+%{key}@appmail.adventuretime.ooo")
+
+      allow(handler).to receive(:execute)
+      allow(handler).to receive(:metrics_params)
+    end
+
+    it "finds the mail key" do
+      expect(Gitlab::Email::Handler).to receive(:for).with(an_instance_of(Mail::Message), 'gitlabhq/gitlabhq+auth_token').and_return(handler)
+
+      receiver.execute
+    end
+  end
+
   context "when we cannot find a capable handler" do
     let(:email_raw) { fixture_file('emails/valid_reply.eml').gsub(mail_key, "!!!") }