Fix "Unsubscribe" link in notification emails that is triggered by anti-virus

* Created a force=true param that will continue with the previous
  behaviour of the unsubscribe method
* Created a filter for not-logged users so they see a unsubsribe
  confirmation page
* Added the List-Unsubscribe header on emails so the email client can
  display it on top

9 files changed, 174 insertions, 20 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 7a19af6b765..1502f03b951 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -69,6 +69,7 @@ v 8.12.0 (unreleased)
   - Test migration paths from 8.5 until current release !4874
   - Replace animateEmoji timeout with eventListener (ClemMakesApps)
   - Optimistic locking for Issues and Merge Requests (title and description overriding prevention)
+  - Require confirmation when not logged in for unsubscribe links !6223 (Maximiliano Perez Coto)
   - Add `wiki_page_events` to project hook APIs (Ben Boeckel)
   - Remove Gitorious import
   - Fix inconsistent background color for filter input field (ClemMakesApps)
diff --git a/app/controllers/sent_notifications_controller.rb b/app/controllers/sent_notifications_controller.rb
index 7271c933b9b..c4abc597cf1 100644
--- a/app/controllers/sent_notifications_controller.rb
+++ b/app/controllers/sent_notifications_controller.rb
@@ -2,13 +2,17 @@ class SentNotificationsController < ApplicationController
   skip_before_action :authenticate_user!
 
   def unsubscribe
+    return redirect_to new_user_session_path unless current_user || params[:force]
+
     @sent_notification = SentNotification.for(params[:id])
+
     return render_404 unless @sent_notification && @sent_notification.unsubscribable?
 
     noteable = @sent_notification.noteable
     noteable.unsubscribe(@sent_notification.recipient)
 
     flash[:notice] = "You have been unsubscribed from this thread."
+
     if current_user
       case noteable
       when Issue
diff --git a/app/mailers/notify.rb b/app/mailers/notify.rb
index 0cc709f68e4..9799f1dc886 100644
--- a/app/mailers/notify.rb
+++ b/app/mailers/notify.rb
@@ -108,6 +108,12 @@ class Notify < BaseMailer
     headers["X-GitLab-#{model.class.name}-ID"] = model.id
     headers['X-GitLab-Reply-Key'] = reply_key
 
+    if !@labels_url && @sent_notification && @sent_notification.unsubscribable?
+      headers['List-Unsubscribe'] = unsubscribe_sent_notification_url(@sent_notification, force: true)
+
+      @sent_notification_url = unsubscribe_sent_notification_url(@sent_notification)
+    end
+
     if Gitlab::IncomingEmail.enabled?
       address = Mail::Address.new(Gitlab::IncomingEmail.reply_address(reply_key))
       address.display_name = @project.name_with_namespace
diff --git a/app/views/layouts/notify.html.haml b/app/views/layouts/notify.html.haml
index dde2e2889dc..1ec4c3f0c67 100644
--- a/app/views/layouts/notify.html.haml
+++ b/app/views/layouts/notify.html.haml
@@ -25,8 +25,8 @@
           - if @labels_url
             adjust your #{link_to 'label subscriptions', @labels_url}.
           - else
-            - if @sent_notification && @sent_notification.unsubscribable?
-              = link_to "unsubscribe", unsubscribe_sent_notification_url(@sent_notification)
+            - if @sent_notification_url
+              = link_to "unsubscribe", @sent_notification_url
               from this thread or
             adjust your notification settings.
 
diff --git a/app/views/sent_notifications/unsubscribe.html.haml b/app/views/sent_notifications/unsubscribe.html.haml
new file mode 100644
index 00000000000..568d2ac3af1
--- /dev/null
+++ b/app/views/sent_notifications/unsubscribe.html.haml
@@ -0,0 +1,4 @@
+%h3.page-title
+  Are you sure you want to unsubscribe from this thread?
+
+  = link_to "Unsubscribe", unsubscribe_sent_notification_path(@sent_notification, force: true), class: 'btn btn-primary wide'
diff --git a/spec/controllers/sent_notifications_controller_spec.rb b/spec/controllers/sent_notifications_controller_spec.rb
index 9ced397bd4a..4e75372ffb2 100644
--- a/spec/controllers/sent_notifications_controller_spec.rb
+++ b/spec/controllers/sent_notifications_controller_spec.rb
@@ -1,25 +1,102 @@
 require 'rails_helper'
 
 describe SentNotificationsController, type: :controller do
-  let(:user)              { create(:user) }
-  let(:issue)             { create(:issue, author: user) }
-  let(:sent_notification) { create(:sent_notification, noteable: issue) }
+  let(:user) { create(:user) }
+  let(:project) { create(:empty_project) }
+  let(:sent_notification) { create(:sent_notification, noteable: issue, recipient: user) }
 
-  describe 'GET #unsubscribe' do
-    it 'returns a 404 when calling without existing id' do
-      get(:unsubscribe, id: '0' * 32)
+  let(:issue) do
+    create(:issue, project: project, author: user) do |issue|
+      issue.subscriptions.create(user: user, subscribed: true)
+    end
+  end
+
+  describe 'GET unsubscribe' do
+    context 'when the user is not logged in' do
+      context 'when the force param is passed' do
+        before { get(:unsubscribe, id: sent_notification.reply_key, force: true) }
+
+        it 'unsubscribes the user' do
+          expect(issue.subscribed?(user)).to be_falsey
+        end
+
+        it 'sets the flash message' do
+          expect(controller).to set_flash[:notice].to(/unsubscribed/).now
+        end
+
+        it 'redirects to the login page' do
+          expect(response).to redirect_to(new_user_session_path)
+        end
+      end
+
+      context 'when the force param is not passed' do
+        before { get(:unsubscribe, id: sent_notification.reply_key) }
+
+        it 'does not unsubscribe the user' do
+          expect(issue.subscribed?(user)).to be_truthy
+        end
 
-      expect(response.status).to be 404
+        it 'does not set the flash message' do
+          expect(controller).not_to set_flash[:notice]
+        end
+
+        it 'redirects to the login page' do
+          expect(response).to redirect_to(new_user_session_path)
+        end
+      end
     end
 
-    context 'calling with id' do
-      it 'shows a flash message to the user' do
-        get(:unsubscribe, id: sent_notification.reply_key)
+    context 'when the user is logged in' do
+      before { sign_in(user) }
+
+      context 'when the ID passed does not exist' do
+        before { get(:unsubscribe, id: sent_notification.reply_key.reverse) }
+
+        it 'does not unsubscribe the user' do
+          expect(issue.subscribed?(user)).to be_truthy
+        end
+
+        it 'does not set the flash message' do
+          expect(controller).not_to set_flash[:notice]
+        end
+
+        it 'returns a 404' do
+          expect(response).to have_http_status(:not_found)
+        end
+      end
+
+      context 'when the force param is passed' do
+        before { get(:unsubscribe, id: sent_notification.reply_key, force: true) }
+
+        it 'unsubscribes the user' do
+          expect(issue.subscribed?(user)).to be_falsey
+        end
+
+        it 'sets the flash message' do
+          expect(controller).to set_flash[:notice].to(/unsubscribed/).now
+        end
+
+        it 'redirects to the issue page' do
+          expect(response).
+            to redirect_to(namespace_project_issue_path(project.namespace, project, issue))
+        end
+      end
+
+      context 'when the force param is not passed' do
+        before { get(:unsubscribe, id: sent_notification.reply_key) }
+
+        it 'unsubscribes the user' do
+          expect(issue.subscribed?(user)).to be_falsey
+        end
 
-        expect(response.status).to be 302
+        it 'sets the flash message' do
+          expect(controller).to set_flash[:notice].to(/unsubscribed/).now
+        end
 
-        expect(response).to redirect_to new_user_session_path
-        expect(controller).to set_flash[:notice].to(/unsubscribed/).now
+        it 'redirects to the issue page' do
+          expect(response).
+            to redirect_to(namespace_project_issue_path(project.namespace, project, issue))
+        end
       end
     end
   end
diff --git a/spec/features/unsubscribe_links_spec.rb b/spec/features/unsubscribe_links_spec.rb
new file mode 100644
index 00000000000..eafad1a726d
--- /dev/null
+++ b/spec/features/unsubscribe_links_spec.rb
@@ -0,0 +1,54 @@
+require 'spec_helper'
+
+describe 'Unsubscribe links', feature: true do
+  include Warden::Test::Helpers
+
+  let(:recipient) { create(:user) }
+  let(:author) { create(:user) }
+  let(:project) { create(:empty_project, :public) }
+  let(:params) { { title: 'A bug!', description: 'Fix it!', assignee: recipient } }
+  let(:issue) { Issues::CreateService.new(project, author, params).execute }
+
+  let(:mail) { ActionMailer::Base.deliveries.last }
+  let(:body) { Capybara::Node::Simple.new(mail.default_part_body.to_s) }
+  let(:header_link) { mail.header['List-Unsubscribe'] }
+  let(:body_link) { body.find_link('unsubscribe')['href'] }
+
+  before do
+    perform_enqueued_jobs { issue }
+  end
+
+  context 'when logged out' do
+    it 'redirects to the login page when visiting the link from the body' do
+      visit body_link
+
+      expect(current_path).to eq new_user_session_path
+      expect(issue.subscribed?(recipient)).to be_truthy
+    end
+
+    it 'unsubscribes from the issue when visiting the link from the header' do
+      visit header_link
+
+      expect(page).to have_text('unsubscribed')
+      expect(issue.subscribed?(recipient)).to be_falsey
+    end
+  end
+
+  context 'when logged in' do
+    before { login_as(recipient) }
+
+    it 'unsubscribes from the issue when visiting the link from the email body' do
+      visit body_link
+
+      expect(page).to have_text('unsubscribed')
+      expect(issue.subscribed?(recipient)).to be_falsey
+    end
+
+    it 'unsubscribes from the issue when visiting the link from the header' do
+      visit header_link
+
+      expect(page).to have_text('unsubscribed')
+      expect(issue.subscribed?(recipient)).to be_falsey
+    end
+  end
+end
diff --git a/spec/mailers/notify_spec.rb b/spec/mailers/notify_spec.rb
index eae9c060c38..0363bc74939 100644
--- a/spec/mailers/notify_spec.rb
+++ b/spec/mailers/notify_spec.rb
@@ -861,7 +861,7 @@ describe Notify do
     subject { Notify.repository_push_email(project.id, author_id: user.id, ref: 'refs/heads/master', action: :create) }
 
     it_behaves_like 'it should not have Gmail Actions links'
-    it_behaves_like "a user cannot unsubscribe through footer link"
+    it_behaves_like 'a user cannot unsubscribe through footer link'
     it_behaves_like 'an email with X-GitLab headers containing project details'
     it_behaves_like 'an email that contains a header with author username'
 
@@ -914,7 +914,7 @@ describe Notify do
     subject { Notify.repository_push_email(project.id, author_id: user.id, ref: 'refs/heads/master', action: :delete) }
 
     it_behaves_like 'it should not have Gmail Actions links'
-    it_behaves_like "a user cannot unsubscribe through footer link"
+    it_behaves_like 'a user cannot unsubscribe through footer link'
     it_behaves_like 'an email with X-GitLab headers containing project details'
     it_behaves_like 'an email that contains a header with author username'
 
@@ -936,7 +936,7 @@ describe Notify do
     subject { Notify.repository_push_email(project.id, author_id: user.id, ref: 'refs/tags/v1.0', action: :delete) }
 
     it_behaves_like 'it should not have Gmail Actions links'
-    it_behaves_like "a user cannot unsubscribe through footer link"
+    it_behaves_like 'a user cannot unsubscribe through footer link'
     it_behaves_like 'an email with X-GitLab headers containing project details'
     it_behaves_like 'an email that contains a header with author username'
 
@@ -964,7 +964,7 @@ describe Notify do
     subject { Notify.repository_push_email(project.id, author_id: user.id, ref: 'refs/heads/master', action: :push, compare: compare, reverse_compare: false, diff_refs: diff_refs, send_from_committer_email: send_from_committer_email) }
 
     it_behaves_like 'it should not have Gmail Actions links'
-    it_behaves_like "a user cannot unsubscribe through footer link"
+    it_behaves_like 'a user cannot unsubscribe through footer link'
     it_behaves_like 'an email with X-GitLab headers containing project details'
     it_behaves_like 'an email that contains a header with author username'
 
@@ -1066,7 +1066,7 @@ describe Notify do
     subject { Notify.repository_push_email(project.id, author_id: user.id, ref: 'refs/heads/master', action: :push, compare: compare, diff_refs: diff_refs) }
 
     it_behaves_like 'it should show Gmail Actions View Commit link'
-    it_behaves_like "a user cannot unsubscribe through footer link"
+    it_behaves_like 'a user cannot unsubscribe through footer link'
     it_behaves_like 'an email with X-GitLab headers containing project details'
     it_behaves_like 'an email that contains a header with author username'
 
diff --git a/spec/mailers/shared/notify.rb b/spec/mailers/shared/notify.rb
index 93de5850ba2..56872da9a8f 100644
--- a/spec/mailers/shared/notify.rb
+++ b/spec/mailers/shared/notify.rb
@@ -169,10 +169,18 @@ shared_examples 'it should show Gmail Actions View Commit link' do
 end
 
 shared_examples 'an unsubscribeable thread' do
+  it 'has a List-Unsubscribe header' do
+    is_expected.to have_header 'List-Unsubscribe', /unsubscribe/
+  end
+
   it { is_expected.to have_body_text /unsubscribe/ }
 end
 
 shared_examples 'a user cannot unsubscribe through footer link' do
+  it 'does not have a List-Unsubscribe header' do
+    is_expected.not_to have_header 'List-Unsubscribe', /unsubscribe/
+  end
+
   it { is_expected.not_to have_body_text /unsubscribe/ }
 end