Merge pull request #1865 from edx/ned/merge-hotfix-2013-12-04-to-master

The changes from hotfix/2013-12-04 that we want permanently

common/djangoapps/student/models.py

@@ -19,7 +19,7 @@ import uuid
 from django.conf import settings
 from django.contrib.auth.models import User
 from django.contrib.auth.signals import user_logged_in, user_logged_out
-from django.db import models
+from django.db import models, IntegrityError
 from django.db.models.signals import post_save
 from django.dispatch import receiver, Signal
 import django.dispatch
@@ -52,7 +52,7 @@ class AnonymousUserId(models.Model):
     http://docs.python.org/2/library/md5.html#md5.digest_size
     """
     user = models.ForeignKey(User, db_index=True)
-    anonymous_user_id = models.CharField(unique=True, max_length=16)
+    anonymous_user_id = models.CharField(unique=True, max_length=32)
     course_id = models.CharField(db_index=True, max_length=255)
     unique_together = (user, course_id)
 
@@ -73,12 +73,30 @@ def anonymous_id_for_user(user, course_id):
     hasher.update(settings.SECRET_KEY)
     hasher.update(str(user.id))
     hasher.update(course_id)
+    digest = hasher.hexdigest()
 
-    return AnonymousUserId.objects.get_or_create(
-        defaults={'anonymous_user_id': hasher.hexdigest()},
+    try:
+        anonymous_user_id, created = AnonymousUserId.objects.get_or_create(
+            defaults={'anonymous_user_id': digest},
             user=user,
             course_id=course_id
-    )[0].anonymous_user_id
+        )
+        if anonymous_user_id.anonymous_user_id != digest:
+            log.error(
+                "Stored anonymous user id {stored!r} for user {user!r} "
+                "in course {course!r} doesn't match computed id {digest!r}".format(
+                    user=user,
+                    course=course_id,
+                    stored=anonymous_user_id.anonymous_user_id,
+                    digest=digest
+                )
+            )
+    except IntegrityError:
+        # Another thread has already created this entry, so
+        # continue
+        pass
+
+    return digest
 
 
 def user_by_anonymous_id(id):

lms/templates/instructor/staff_grading.html

@@ -22,9 +22,10 @@
 <h1>${_("Staff grading")}</h1>
 <div class="breadcrumbs"></div>
 <div class="error-container"></div>
+
 <div class="message-container"></div>
 
-<! -- Problem List View -->
+<!-- Problem List View -->
 <section class="problem-list-container">
   <h2>${_("Instructions")}</h2>
   <div class="instructions">

lms/templates/open_ended_problems/combined_notifications.html

@@ -16,6 +16,7 @@
 <section class="container">
     <div class="combined-notifications" data-ajax_url="${ajax_url}">
         <div class="error-container">${error_text}</div>
+
         <h1>${_("Open Ended Console")}</h1>
         <h2>${_("Instructions")}</h2>
         <p>${_("Here are items that could potentially need your attention.")}</p>

lms/templates/open_ended_problems/open_ended_flagged_problems.html

@@ -19,6 +19,7 @@
 <section class="container">
     <div class="open-ended-problems" data-ajax_url="${ajax_url}">
         <div class="error-container">${error_text}</div>
+
         <h1>${_("Flagged Open Ended Problems")}</h1>
         <h2>${_("Instructions")}</h2>
         <p>${_("Here are a list of open ended problems for this course that have been flagged by students as potentially inappropriate.")}</p>