master courses: fix updating question bank questions

test plan:
* create a blueprint course
* create a question bank with a question
* create a quiz with a group linked to the bank
 and lock the quiz

* sync to associated course
* in the associated course,
 update a question in the question bank
* preview the quiz
* it should not kersplode

closes #ADMIN-328

Change-Id: Ib2c611dc16472c83acc8c590b0584c0820ef2317
Reviewed-on: https://gerrit.instructure.com/131591
Tested-by: Jenkins
Reviewed-by: Mysti Sadler <mysti@instructure.com>
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
QA-Review: Deepeeca Soundarrajan <dsoundarrajan@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>

app/models/master_courses/collection_restrictor.rb

@@ -48,9 +48,9 @@ module MasterCourses::CollectionRestrictor
     end
   end
 
-  def check_restrictions_on_creation?
+  def check_restrictions?
     if self.is_a?(Quizzes::QuizQuestion)
-      !self.generated?
+      !self.generated? # allow updating through the bank even though it's technically locked... shhh don't tell anybody
     else
       true
     end

app/models/master_courses/restrictor.rb

@@ -65,8 +65,7 @@ module MasterCourses::Restrictor
     end
 
     def check_for_restricted_column_changes
-      return true if @importing_migration || !is_child_content?
-      return true if new_record? && !self.check_restrictions_on_creation? # shouldn't be able to create new collection items if owner is locked
+      return true if @importing_migration || !is_child_content? || !self.check_restrictions?
 
       restrictions = nil
       locked_columns = []
@@ -101,8 +100,8 @@ module MasterCourses::Restrictor
     end
   end
 
-  def check_restrictions_on_creation?
-    false
+  def check_restrictions?
+    !self.new_record?
   end
 
   def mark_downstream_changes(changed_columns=nil)

spec/models/master_courses/collection_restrictor_spec.rb

@@ -64,12 +64,14 @@ describe MasterCourses::CollectionRestrictor do
       expect(new_aq.errors[:base].first.to_s).to include("locked by Master Course")
     end
 
-    it "should allow quiz questions to be generated" do
+    it "should allow quiz questions to be generated and updated" do
       original_quiz = @copy_from.quizzes.create!
       quiz_tag = @template.create_content_tag_for!(original_quiz, :restrictions => {:content => true})
 
       quiz_copy = @copy_to.quizzes.create!(:migration_id => quiz_tag.migration_id)
-      quiz_copy.quiz_questions.create!(:question_data => {'some data' => '1'}, :workflow_state => "generated")
+      qq = quiz_copy.quiz_questions.create!(:question_data => {'some data' => '1'}, :workflow_state => "generated")
+
+      qq.update_attribute(:question_data, {'some other data' => '1'})
     end
   end