diff --git a/django/contrib/comments/views/comments.py b/django/contrib/comments/views/comments.py
index e583d9d3ed..264d5a8b13 100644
--- a/django/contrib/comments/views/comments.py
+++ b/django/contrib/comments/views/comments.py
@@ -37,7 +37,7 @@ def post_comment(request, next=None):
     data = request.POST.copy()
     if request.user.is_authenticated():
         if not data.get('name', ''):
-            data["name"] = request.user.get_full_name()
+            data["name"] = request.user.get_full_name() or request.user.username
         if not data.get('email', ''):
             data["email"] = request.user.email
 
diff --git a/tests/regressiontests/comment_tests/tests/comment_view_tests.py b/tests/regressiontests/comment_tests/tests/comment_view_tests.py
index bd9fb4144d..f82a5e17d8 100644
--- a/tests/regressiontests/comment_tests/tests/comment_view_tests.py
+++ b/tests/regressiontests/comment_tests/tests/comment_view_tests.py
@@ -85,7 +85,7 @@ class CommentViewTests(CommentTestCase):
         c = Comment.objects.all()[0]
         self.assertEqual(c.ip_address, "1.2.3.4")
         self.assertEqual(c.comment, "This is my comment")
-        
+
     def testPostAsAuthenticatedUser(self):
         a = Article.objects.get(pk=1)
         data = self.getValidData(a)
@@ -101,6 +101,23 @@ class CommentViewTests(CommentTestCase):
         self.assertEqual(c.user_name, u.get_full_name())
         self.assertEqual(c.user_email, u.email)
 
+    def testPostAsAuthenticatedUserWithoutFullname(self):
+        """
+        Check that the user's name in the comment is populated for
+        authenticated users without first_name and last_name.
+        """
+        user = User.objects.create_user(username='jane_other',
+                email='jane@example.com', password='jane_other')
+        a = Article.objects.get(pk=1)
+        data = self.getValidData(a)
+        data['name'] = data['email'] = ''
+        self.client.login(username="jane_other", password="jane_other")
+        self.response = self.client.post("/post/", data, REMOTE_ADDR="1.2.3.4")
+        c = Comment.objects.get(user=user)
+        self.assertEqual(c.ip_address, "1.2.3.4")
+        self.assertEqual(c.user_name, 'jane_other')
+        user.delete()
+
     def testPreventDuplicateComments(self):
         """Prevent posting the exact same comment twice"""
         a = Article.objects.get(pk=1)
@@ -131,7 +148,7 @@ class CommentViewTests(CommentTestCase):
         # Post a comment and check the signals
         self.testCreateValidComment()
         self.assertEqual(received_signals, excepted_signals)
-        
+
     def testWillBePostedSignal(self):
         """
         Test that the comment_will_be_posted signal can prevent the comment from