restore ssa and discussions using undelete

fixes COMMS-1048

Test Plan:
- Delete a section specific announcement
- go to http://localhost:3000/courses/:id/undelete
- see the deleted section specific announcement
- click restore
- refresh the page
- notice its no longer on the undelete page
- go to the announcements page
- notice it has shown back up

Change-Id: Ief3a2d4356b85759e6d45021143bd9b68717ac35
Reviewed-on: https://gerrit.instructure.com/147142
Reviewed-by: Aaron Kc Hsu <ahsu@instructure.com>
Tested-by: Jenkins
QA-Review: Venk Natarajan <vnatarajan@instructure.com>
Product-Review: Steven Burnett <sburnett@instructure.com>

app/models/discussion_topic.rb

@@ -952,6 +952,12 @@ class DiscussionTopic < ActiveRecord::Base
   end
 
   def restore(from=nil)
+    if self.is_section_specific?
+      DiscussionTopicSectionVisibility.where(discussion_topic_id: self.id).to_a.uniq(&:course_section_id).each do |dtsv|
+        dtsv.workflow_state = 'active'
+        dtsv.save
+      end
+    end
     self.workflow_state = can_unpublish? ? 'unpublished' : 'active'
     self.save
 

spec/models/discussion_topic_spec.rb

@@ -1957,6 +1957,24 @@ describe DiscussionTopic do
       expect(ann.reload).to be_active
     end
 
+    it "should restore an announcement to active state with sections" do
+      section = @course.course_sections.create!
+      @course.save!
+      announcement = Announcement.create!(
+        :title => "some topic",
+        :message => "I announce that i am lying",
+        :user => @teacher,
+        :context => @course,
+        :workflow_state => "published"
+      )
+      add_section_to_topic(announcement, section)
+      announcement.save!
+      announcement.destroy
+
+      announcement.restore
+      expect(announcement.reload).to be_active
+    end
+
     it "should restore a topic with submissions to active state" do
       discussion_topic_model(:context => @course)
       @topic.reply_from(user: @student, text: "huttah!")