Reverted 905e33f, now that DatabaseFeatures does not need confirm

Connection.features does not need to be confirmed any more, after commit aa42357, rendering obsolete the workaround when using TEST_MIRROR (Refs django#16885, django#17760).

Author: claudep

django/test/simple.py

@@ -320,7 +320,6 @@ def setup_databases(self, **kwargs):
  mirrors.append((alias, connections[alias].settings_dict['NAME']))
  connections[alias].settings_dict['NAME'] = (
  connections[mirror_alias].settings_dict['NAME'])
- connections[alias].features = connections[mirror_alias].features
 
  return old_names, mirrors
 

tests/regressiontests/test_runner/tests.py

@@ -204,28 +204,6 @@ def test_all_options_given(self):
  self.assertOutput(out, 'bar:foo:31337')
 
 
-class Ticket16885RegressionTests(unittest.TestCase):
- def test_ticket_16885(self):
- """Features are also confirmed on mirrored databases."""
- old_db_connections = db.connections
- try:
- db.connections = db.ConnectionHandler({
- 'default': {
- 'ENGINE': 'django.db.backends.sqlite3',
- },
- 'slave': {
- 'ENGINE': 'django.db.backends.sqlite3',
- 'TEST_MIRROR': 'default',
- },
- })
- slave = db.connections['slave']
- self.assertEqual(slave.features.supports_transactions, None)
- DjangoTestSuiteRunner(verbosity=0).setup_databases()
- self.assertNotEqual(slave.features.supports_transactions, None)
- finally:
- db.connections = old_db_connections
-
-
 class Ticket17477RegressionTests(AdminScriptTestCase):
  def setUp(self):
  self.write_settings('settings.py')