Fix up authentication, other things

lms/djangoapps/courseware/tabs.py

@@ -112,6 +112,7 @@ def _staff_grading(tab, user, course, active_page):
     return []
 
 def _peer_grading(tab, user, course, active_page):
+    if user.is_authenticated():
         link = reverse('peer_grading', args=[course.id])
         peer_gs = PeerGradingService(settings.PEER_GRADING_INTERFACE)
         pending_grading=False
@@ -131,8 +132,9 @@ def _peer_grading(tab, user, course, active_page):
         if pending_grading:
             img_path = "/static/images/slider-handle.png"
 
-    tab = [CourseTab(tab_name, link, active_page == "peer_grading", True, img_path)]
+        tab = [CourseTab(tab_name, link, active_page == "peer_grading", pending_grading, img_path)]
         return tab
+    return []
 
 #### Validators