diff --git a/django/contrib/comments/forms.py b/django/contrib/comments/forms.py
index 4ecc4c4..097b3f4 100644
--- a/django/contrib/comments/forms.py
+++ b/django/contrib/comments/forms.py
@@ -106,7 +106,7 @@ class CommentDetailsForm(CommentSecurityForm):
     """
     Handles the specific details of the comment (name, comment, etc.).
     """
-    name          = forms.CharField(label=_("Name"), max_length=50)
+    name          = forms.CharField(label=_("Name"), max_length=61)
     email         = forms.EmailField(label=_("Email address"))
     url           = forms.URLField(label=_("URL"), required=False)
     comment       = forms.CharField(label=_('Comment'), widget=forms.Textarea,
diff --git a/django/contrib/comments/models.py b/django/contrib/comments/models.py
index 5e128d2..d1e2ac8 100644
--- a/django/contrib/comments/models.py
+++ b/django/contrib/comments/models.py
@@ -49,7 +49,7 @@ class Comment(BaseCommentAbstractModel):
     # was posted by a non-authenticated user.
     user        = models.ForeignKey(User, verbose_name=_('user'),
                     blank=True, null=True, related_name="%(class)s_comments")
-    user_name   = models.CharField(_("user's name"), max_length=50, blank=True)
+    user_name   = models.CharField(_("user's name"), max_length=61, blank=True)
     user_email  = models.EmailField(_("user's email address"), blank=True)
     user_url    = models.URLField(_("user's URL"), blank=True)
 
diff --git a/tests/regressiontests/comment_tests/tests/comment_view_tests.py b/tests/regressiontests/comment_tests/tests/comment_view_tests.py
index b8a62b4..106f249 100644
--- a/tests/regressiontests/comment_tests/tests/comment_view_tests.py
+++ b/tests/regressiontests/comment_tests/tests/comment_view_tests.py
@@ -135,8 +135,28 @@ class CommentViewTests(CommentTestCase):
         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 testPostAsAuthenticatedUserWithLongFullname(self):
+        """
+        Check that the user's name in the comment is populated for
+        authenticated users with a long first_name and last_name (up to 30
+        characters each).
+        Refs #14175.
+        """
+        user = User.objects.create_user(username='jane_other',
+                email='jane@example.com', password='jane_other')
+        user.first_name = 'Loooong First Name of 30 Chars'
+        user.last_name = 'Looooong Last Name of 30 Chars'
+        user.save()
+        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, 'Loooong First Name of 30 Chars Looooong Last Name of 30 Chars')        
+        
     def testPreventDuplicateComments(self):
         """Prevent posting the exact same comment twice"""
         a = Article.objects.get(pk=1)