Copy arguments passed to Redis

The Redis backend now creates a copy of the "arguments" dictionary passed
to it, before popping values out of it.  This prevents the given
dictionary from losing its keys.

Change-Id: I17c5891cea82c2edaa09290ff974a261f909a811
(cherry picked from commit 4ca3e02f21338a3566697a84c12366b7b1950de5)

2 files changed, 6 insertions, 4 deletions

diff --git a/tests/cache/_fixtures.py b/tests/cache/_fixtures.py
index 04fdca3..15cbcf1 100644
--- a/tests/cache/_fixtures.py
+++ b/tests/cache/_fixtures.py
@@ -17,7 +17,8 @@ class _GenericBackendFixture(object):
     def setup_class(cls):
         try:
             backend_cls = _backend_loader.load(cls.backend)
-            backend = backend_cls(cls.config_args.get('arguments', {}))
+            arguments = cls.config_args.get('arguments', {})
+            backend = backend_cls(arguments)
         except ImportError:
             pytest.skip("Backend %s not installed" % cls.backend)
         cls._check_backend_available(backend)
@@ -64,7 +65,8 @@ class _GenericBackendFixture(object):
     def _backend(self):
         backend_cls = _backend_loader.load(self.backend)
         _config_args = self.config_args.copy()
-        self._backend_inst = backend_cls(_config_args.get('arguments', {}))
+        arguments = _config_args.get('arguments', {})
+        self._backend_inst = backend_cls(arguments)
         return self._backend_inst
 
 
diff --git a/tests/cache/test_redis_backend.py b/tests/cache/test_redis_backend.py
index e8fdd2a..c91ac09 100644
--- a/tests/cache/test_redis_backend.py
+++ b/tests/cache/test_redis_backend.py
@@ -32,6 +32,7 @@ class RedisTest(_TestRedisConn, _GenericBackendTest):
             'host': REDIS_HOST,
             'port': REDIS_PORT,
             'db': 0,
+            "foo": "barf"
         }
     }
 
@@ -62,8 +63,7 @@ class RedisConnectionTest(TestCase):
 
     def _test_helper(self, mock_obj, expected_args, connection_args=None):
         if connection_args is None:
-            # The redis backend pops items from the dict, so we copy
-            connection_args = expected_args.copy()
+            connection_args = expected_args
 
         self.backend_cls(connection_args)
         mock_obj.assert_called_once_with(**expected_args)