Merge branch 'fix-slashes-in-wiki-urls' into 'master'

Fix bug where Wiki pages that include a '/' were no longer accessible

### What does this MR do?

This MR fixes a regression that caused Wiki pages that included a '/' to no longer be accessible.

### Are there points in the code the reviewer needs to double check?

Are there cases that `wiki_helper.rb` doesn't handle?

### Why was this MR needed?

The upgrade from Rails v4.1.2 to v4.1.9 (76aad9b7) caused slashes in a model ID to be escaped automatically. We can no longer use the built-in the URL helpers to generate the links for Wiki pages if we want to maintain support for slashes. There is no option to tell the formatter otherwise:

http://stackoverflow.com/questions/25031791/rails-4-1-2-to-param-escapes-slashes-and-breaks-app

The Rails code in question is here:

https://github.com/rails/rails/blob/4-1-stable/actionpack/lib/action_dispatch/journey/visitors.rb#L159

### What are the relevant issue numbers / [Feature requests](http://feedback.gitlab.com/)?

#1363

See merge request !502

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 7.10.0 (unreleased)
+  - Fix bug where Wiki pages that included a '/' were no longer accessible (Stan Hu)
   - Fix bug where error messages from Dropzone would not be displayed on the issues page (Stan Hu)
   - Add ability to configure Reply-To address in gitlab.yml (Stan Hu)
   - Fix broken side-by-side diff view on merge request page (Stan Hu)

app/controllers/projects/wikis_controller.rb

@@ -5,6 +5,7 @@ class Projects::WikisController < Projects::ApplicationController
   before_filter :authorize_write_wiki!, only: [:edit, :create, :history]
   before_filter :authorize_admin_wiki!, only: :destroy
   before_filter :load_project_wiki
+  include WikiHelper
 
   def pages
     @wiki_pages = Kaminari.paginate_array(@project_wiki.pages).page(params[:page]).per(PER_PAGE)
@@ -45,7 +46,10 @@ class Projects::WikisController < Projects::ApplicationController
     return render('empty') unless can?(current_user, :write_wiki, @project)
 
     if @page.update(content, format, message)
-      redirect_to [@project.namespace.becomes(Namespace), @project, @page], notice: 'Wiki was successfully updated.'
+      redirect_to(
+        namespace_project_wiki_path(@project.namespace, @project, @page),
+        notice: 'Wiki was successfully updated.'
+      )
     else
       render 'edit'
     end

app/helpers/wiki_helper.rb

+module WikiHelper
+  # Rails v4.1.9+ escapes all model IDs, converting slashes into %2F. The
+  # only way around this is to implement our own path generators.
+  def namespace_project_wiki_path(namespace, project, wiki_page, *args)
+    slug =
+        case wiki_page
+        when Symbol
+          wiki_page
+        else
+          wiki_page.slug
+        end
+    namespace_project_path(namespace, project) + "/wikis/#{slug}"
+  end
+
+  def edit_namespace_project_wiki_path(namespace, project, wiki_page, *args)
+    namespace_project_wiki_path(namespace, project, wiki_page) + '/edit'
+  end
+
+  def history_namespace_project_wiki_path(namespace, project, wiki_page, *args)
+    namespace_project_wiki_path(namespace, project, wiki_page) + '/history'
+  end
+end

features/project/wiki.feature

@@ -62,3 +62,27 @@ Feature: Project Wiki
     And I browse to wiki page with images
     And I click on image link
     Then I should see the new wiki page form
+
+  @javascript
+  Scenario: New Wiki page that has a path
+    Given I create a New page with paths
+    And I click on the "Pages" button
+    Then I should see non-escaped link in the pages list
+
+  @javascript
+  Scenario: Edit Wiki page that has a path
+    Given I create a New page with paths
+    And I click on the "Pages" button
+    And I edit the Wiki page with a path
+    Then I should see a non-escaped path
+    And I should see the Editing page
+    And I change the content
+    Then I should see the updated content
+
+  @javascript
+  Scenario: View the page history of a Wiki page that has a path
+    Given I create a New page with paths
+    And I click on the "Pages" button
+    And I view the page history of a Wiki page that has a path
+    Then I should see a non-escaped path
+    And I should see the page history

features/steps/project/wiki.rb

@@ -3,6 +3,7 @@ class Spinach::Features::ProjectWiki < Spinach::FeatureSteps
   include SharedProject
   include SharedNote
   include SharedPaths
+  include WikiHelper
 
   step 'I click on the Cancel button' do
     within(:css, ".form-actions") do
@@ -123,6 +124,41 @@ class Spinach::Features::ProjectWiki < Spinach::FeatureSteps
     page.should have_content('Editing - image.jpg')
   end
 
+  step 'I create a New page with paths' do
+    click_on 'New Page'
+    fill_in 'Page slug', with: 'one/two/three'
+    click_on 'Build'
+    fill_in "wiki_content", with: 'wiki content'
+    click_on "Create page"
+    current_path.should include 'one/two/three'
+  end
+
+  step 'I should see non-escaped link in the pages list' do
+    page.should have_xpath("//a[@href='/#{project.path_with_namespace}/wikis/one/two/three']")
+  end
+
+  step 'I edit the Wiki page with a path' do
+    click_on 'three'
+    click_on 'Edit'
+  end
+
+  step 'I should see a non-escaped path' do
+    current_path.should include 'one/two/three'
+  end
+
+  step 'I should see the Editing page' do
+    page.should have_content('Editing')
+  end
+
+  step 'I view the page history of a Wiki page that has a path' do
+    click_on 'three'
+    click_on 'Page History'
+  end
+
+  step 'I should see the page history' do
+    page.should have_content('History for')
+  end
+
   def wiki
     @project_wiki = ProjectWiki.new(project, current_user)
   end