redirect to wiki context on wiki revision rollback

fixes #9693

the redirect that occurerd after rolling a wiki page back to a previous
versioin assumed that it was a course wiki, so group wiki page rollbacks worked
correctly but redirected to the wrong place.

test plan:
- make a group wiki page, edit and save a few times
- roll back to a previous version
- you should be redirected back to the right wiki page

Change-Id: Ic7ad6cc3802f39577fad0a08fcfbe78ee6941980
Reviewed-on: https://gerrit.instructure.com/12752
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>

app/controllers/wiki_page_revisions_controller.rb

@@ -74,9 +74,10 @@ class WikiPageRevisionsController < ApplicationController
   def update
     if authorized_action(@page, @current_user, :update)
       @revision = @page.versions.find(params[:id])
-      @page.revert_to_version @revision
+      except_fields = [:id] + WikiPage.new.attributes.keys - WikiPage.accessible_attributes.to_a
+      @page.revert_to_version @revision, :except => except_fields
       flash[:notice] = t('notices.page_rolled_back', 'Page was successfully rolled-back to previous version.')
-      redirect_to course_wiki_page_url( @context.id, @page)
+      redirect_to polymorphic_url([@context, @page])
     end
   end
 end

spec/controllers/wiki_page_revisions_controller_spec.rb

@@ -0,0 +1,49 @@
+#
+# Copyright (C) 2011 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')
+
+describe WikiPageRevisionsController do
+  describe "PUT 'update'" do
+    it "should redirect to the right course wiki page" do
+      course_with_teacher_logged_in(:active_all => true)
+      @page = @course.wiki.wiki_pages.create!(:title => "a page")
+      @page.title = "a better page title"
+      @page.save!
+
+      @version = @page.reload.versions.first
+      put 'update', :course_id => @course.id, :wiki_page_id => @page.id, :id => @version.id
+      response.should be_redirect
+      response.location.should match(%r{/courses/#{@course.id}/wiki})
+    end
+
+    it "should redirect to the right group wiki page" do
+      course_with_teacher_logged_in(:active_all => true)
+      gcs = @course.group_categories.create!
+      @group = gcs.groups.create(:context => @course)
+      @page = @group.wiki.wiki_pages.create!(:title => "a page")
+      @page.title = "a better page title"
+      @page.save!
+
+      @version = @page.reload.versions.first
+      put 'update', :group_id => @group.id, :wiki_page_id => @page.id, :id => @version.id
+      response.should be_redirect
+      response.location.should match(%r{/groups/#{@group.id}/wiki})
+    end
+  end
+end