Make sure to test for unicode usernames, since the collate on the username field is latin1

data/model/legacy.py

@@ -792,6 +792,12 @@ def get_matching_users(username_prefix, robot_namespace=None,
 
 
 def verify_user(username_or_email, password):
+  # Make sure we didn't get any unicode for the username.
+  try:
+    str(username_or_email)
+  except ValueError:
+    return None
+
   try:
     fetched = User.get((User.username == username_or_email) |
                        (User.email == username_or_email))

test/test_api_usage.py

@@ -470,6 +470,12 @@ class TestCreateNewUser(ApiTestCase):
     self.assertInTeam(json, NEW_USER_DETAILS['username'])
 
 
+class TestSignin(ApiTestCase):
+  def test_signin_unicode(self):
+    self.postResponse(Signin, data=dict(username=u'\xe5\x8c\x97\xe4\xba\xac\xe5\xb8\x82',
+                                        password='password'), expected_code=403)
+
+
 class TestSignout(ApiTestCase):
   def test_signout(self):
     self.login(READ_ACCESS_USER)