Fix adding pages domain to projects in groups

CHANGELOG-EE

 Please view this file on the master branch, on stable branches it's out of date.
 
+v 8.5.1
+  - Fix adding pages domain to projects in groups
+
 v 8.5.0 (unreleased)
   - Show warning when mirror repository default branch could not be updated because it has diverged from upstream.
   - More reliable wiki indexer

app/views/projects/pages_domains/_form.html.haml

-= form_for [@project.namespace, @project, @domain], html: { class: 'form-horizontal fieldset-form' } do |f|
+= form_for [@project.namespace.becomes(Namespace), @project, @domain], html: { class: 'form-horizontal fieldset-form' } do |f|
   - if @domain.errors.any?
     #error_explanation
       .alert.alert-danger

features/project/pages.feature

@@ -40,6 +40,15 @@ Feature: Project Pages
     And I click on "Create New Domain"
     Then I should see a new domain added
 
+  Scenario: I should be able to add a new domain for project in group namespace
+    Given I own a project in some group namespace
+    And pages are enabled
+    And pages are exposed on external HTTP address
+    When I visit add a new Pages Domain
+    And I fill the domain
+    And I click on "Create New Domain"
+    Then I should see a new domain added
+
   Scenario: I should be denied to add the same domain twice
     Given pages are enabled
     And pages are exposed on external HTTP address

features/steps/shared/project.rb

@@ -7,6 +7,12 @@ module SharedProject
     @project.team << [@user, :master]
   end
 
+  step "I own a project in some group namespace" do
+    @group = create(:group, name: 'some group')
+    @project = create(:project, namespace: @group)
+    @project.team << [@user, :master]
+  end
+
   step "project exists in some group namespace" do
     @group = create(:group, name: 'some group')
     @project = create(:project, namespace: @group)