Fixed #19833 -- Fixed import parameter encoding in get_runner

Thanks Danilo Bargen for the report.

django/test/utils.py

@@ -4,12 +4,13 @@ from xml.dom.minidom import parseString, Node
 
 from django.conf import settings, UserSettingsHolder
 from django.core import mail
-from django.test.signals import template_rendered, setting_changed
 from django.template import Template, loader, TemplateDoesNotExist
 from django.template.loaders import cached
-from django.utils.translation import deactivate
+from django.test.signals import template_rendered, setting_changed
+from django.utils.encoding import force_str
 from django.utils.functional import wraps
 from django.utils import six
+from django.utils.translation import deactivate
 
 
 __all__ = (
@@ -133,7 +134,7 @@ def get_runner(settings, test_runner_class=None):
         test_module_name = '.'.join(test_path[:-1])
     else:
         test_module_name = '.'
-    test_module = __import__(test_module_name, {}, {}, test_path[-1])
+    test_module = __import__(test_module_name, {}, {}, force_str(test_path[-1]))
     test_runner = getattr(test_module, test_path[-1])
     return test_runner
 

tests/regressiontests/test_runner/tests.py

@@ -1,7 +1,7 @@
 """
 Tests for django test runner
 """
-from __future__ import absolute_import
+from __future__ import absolute_import, unicode_literals
 
 import sys
 from optparse import make_option
@@ -150,6 +150,11 @@ class ManageCommandTests(unittest.TestCase):
         self.assertTrue(MockTestRunner.invoked,
                         "The custom test runner has not been invoked")
 
+    def test_bad_test_runner(self):
+        with self.assertRaises(AttributeError):
+            call_command('test', 'sites',
+                testrunner='regressiontests.test_runner.NonExistentRunner')
+
 
 class CustomOptionsTestRunner(simple.DjangoTestSuiteRunner):
     option_list = (