Allow to create service desk issues for all quoted emails

Handles a special case when an email is forwarded
without anything new on its content. In this situation
all lines of email body will be quoted.

Changelog: fixed

lib/gitlab/email/handler/service_desk_handler.rb

@@ -108,7 +108,7 @@ module Gitlab
         end
 
         def message_including_template
-          description = message_including_reply
+          description = process_message(trim_reply: false, allow_only_quotes: true)
           template_content = service_desk_setting&.issue_template_content
 
           if template_content.present?

lib/gitlab/email/reply_parser.rb

@@ -4,12 +4,13 @@
 module Gitlab
   module Email
     class ReplyParser
-      attr_accessor :message
+      attr_accessor :message, :allow_only_quotes
 
-      def initialize(message, trim_reply: true, append_reply: false)
+      def initialize(message, trim_reply: true, append_reply: false, allow_only_quotes: false)
         @message = message
         @trim_reply = trim_reply
         @append_reply = append_reply
+        @allow_only_quotes = allow_only_quotes
       end
 
       def execute
@@ -25,7 +26,12 @@ module Gitlab
         # NOTE: We currently don't support empty quotes.
         # EmailReplyTrimmer allows this as a special case,
         # so we detect it manually here.
-        return "" if body.lines.all? { |l| l.strip.empty? || l.start_with?('>') }
+        #
+        # If allow_only_quotes is true a message where all lines starts with ">" is allowed.
+        # This could happen if an email has an empty quote, forwarded without any new content.
+        return "" if body.lines.all? do |l|
+          l.strip.empty? || (!allow_only_quotes && l.start_with?('>'))
+        end
 
         encoded_body = body.force_encoding(encoding).encode("UTF-8")
         return encoded_body unless @append_reply

spec/fixtures/emails/service_desk_all_quoted.eml

+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+email-test-project_id-issue-@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>
+To: incoming+email-test-project_id-issue-@appmail.adventuretime.ooo
+Message-ID: <CADkmRc+rNGAGGbV2iE5p918UVy4UyJqVcXRO2=otppgzduJSg@mail.gmail.com>
+Subject: The message subject! @all
+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
+
+> This is an empty quote
+> someone did forward this email without
+> adding any new content.

spec/lib/gitlab/email/handler/service_desk_handler_spec.rb

@@ -197,6 +197,17 @@ RSpec.describe Gitlab::Email::Handler::ServiceDeskHandler do
         end
       end
 
+      context 'when all lines of email are quoted' do
+        let(:email_raw) { email_fixture('emails/service_desk_all_quoted.eml') }
+
+        it 'creates email with correct body' do
+          receiver.execute
+
+          issue = Issue.last
+          expect(issue.description).to include('> This is an empty quote')
+        end
+      end
+
       context 'when using custom service desk address' do
         let(:receiver) { Gitlab::Email::ServiceDeskReceiver.new(email_raw) }
 

spec/lib/gitlab/email/reply_parser_spec.rb

@@ -21,6 +21,30 @@ RSpec.describe Gitlab::Email::ReplyParser do
       expect(test_parse_body(fixture_file("emails/no_content_reply.eml"))).to eq("")
     end
 
+    context 'when allow_only_quotes is true' do
+      it "returns quoted text from email" do
+        text = test_parse_body(fixture_file("emails/no_content_reply.eml"), allow_only_quotes: true)
+
+        expect(text).to eq(
+          <<-BODY.strip_heredoc.chomp
+            >
+            >
+            >
+            > eviltrout posted in 'Adventure Time Sux' on Discourse Meta:
+            >
+            > ---
+            > hey guys everyone knows adventure time sucks!
+            >
+            > ---
+            > Please visit this link to respond: http://localhost:3000/t/adventure-time-sux/1234/3
+            >
+            > To unsubscribe from these emails, visit your [user preferences](http://localhost:3000/user_preferences).
+            >
+          BODY
+        )
+      end
+    end
+
     it "properly renders plaintext-only email" do
       expect(test_parse_body(fixture_file("emails/plaintext_only.eml")))
         .to eq(