allow comments download in soft concluded courses

closes GRADE-1994

Test Plan
- As a teacher, create an assignment.
- Leave some submission comments.
- As an admin, set the term to have a concluded date in the past.
- As a teacher, navigate to the now soft-deleted course.
- Navigate to SpeedGrader and attempt to download the submission
  comments.
- Verify that the submission comment pdf renders.

Change-Id: I1e45f07bbd8ea2483d93de894f1f3108635889ac
Reviewed-on: https://gerrit.instructure.com/182369
Tested-by: Jenkins
Reviewed-by: Jeremy Neander <jneander@instructure.com>
Reviewed-by: Derek Bender <djbender@instructure.com>
Reviewed-by: Adrian Packel <apackel@instructure.com>
QA-Review: James Butters <jbutters@instructure.com>
Product-Review: Keith Garner <kgarner@instructure.com>

app/controllers/submission_comments_controller.rb

@@ -21,8 +21,9 @@ class SubmissionCommentsController < ApplicationController
 
   def index
     submission = Submission.preload(assignment: :context, all_submission_comments: :author).find(params[:submission_id])
+    course = submission.assignment.context
     return render_unauthorized_action if submission.assignment.anonymize_students?
-    return render_unauthorized_action unless submission.grants_all_rights?(@current_user, :read_grade, :read_comments)
+    return render_unauthorized_action unless course.grants_any_right?(@current_user, :manage_grades, :view_all_grades)
 
     render pdf: :index, locals: index_pdf_locals(submission)
   end

spec/controllers/submission_comments_controller_spec.rb

@@ -21,10 +21,10 @@ require_relative '../spec_helper'
 RSpec.describe SubmissionCommentsController do
   describe "GET 'index'" do
     before :once do
-      course = Account.default.courses.create!
-      @teacher = course_with_teacher(course: course, active_all: true).user
-      @student = course_with_student(course: course, active_all: true).user
-      @assignment = course.assignments.create!
+      @course = Account.default.courses.create!
+      @teacher = course_with_teacher(course: @course, active_all: true).user
+      @student = course_with_student(course: @course, active_all: true).user
+      @assignment = @course.assignments.create!
       @submission = @assignment.submissions.find_by!(user: @student)
       @submission.submission_comments.create!(author: @teacher, comment: 'a comment')
     end
@@ -42,6 +42,20 @@ RSpec.describe SubmissionCommentsController do
         specify { expect(response.headers.fetch('Content-Type')).to match(/\Aapplication\/pdf/) }
       end
 
+      context "when course is in a concluded term" do
+        before :once do
+          @course.enrollment_term.update!(end_at: 1.day.ago)
+        end
+
+        before do
+          get :index, params: { submission_id: @submission.id }, format: :pdf
+        end
+
+        specify { expect(response).to have_http_status :ok }
+        specify { expect(response).to render_template(:index) }
+        specify { expect(response.headers.fetch('Content-Type')).to match(/\Aapplication\/pdf/) }
+      end
+
       context 'given a request where no submission is present' do
         before do
           @submission.all_submission_comments.destroy_all