From d2333912085fc3bd827295f2bc8253d6723c242b Mon Sep 17 00:00:00 2001
From: Lucas Connors <lucas.revolutiontech@gmail.com>
Date: Fri, 20 Oct 2017 11:09:03 -0400
Subject: [PATCH] Refs #19130 -- Added a test for AuthenticationForm.username
 max_length.

This will be a more useful regression test after refs #27515.
---
 tests/auth_tests/test_forms.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tests/auth_tests/test_forms.py b/tests/auth_tests/test_forms.py
index e5cd05d0d8..f7d0e71ea9 100644
--- a/tests/auth_tests/test_forms.py
+++ b/tests/auth_tests/test_forms.py
@@ -377,6 +377,18 @@ class AuthenticationFormTest(TestDataMixin, TestCase):
         self.assertTrue(form.is_valid())
         self.assertEqual(form.non_field_errors(), [])
 
+    @override_settings(AUTH_USER_MODEL='auth_tests.IntegerUsernameUser')
+    def test_username_field_max_length_defaults_to_254(self):
+        self.assertIsNone(IntegerUsernameUser._meta.get_field('username').max_length)
+        data = {
+            'username': '0123456',
+            'password': 'password',
+        }
+        IntegerUsernameUser.objects.create_user(**data)
+        form = AuthenticationForm(None, data)
+        self.assertEqual(form.fields['username'].max_length, 254)
+        self.assertEqual(form.errors, {})
+
     def test_username_field_label(self):
 
         class CustomAuthenticationForm(AuthenticationForm):