Merge remote-tracking branch 'origin/master' into 2.4.0

Conflicts:
	.travis.yml
	docs/api-guide/fields.md
	docs/api-guide/routers.md
	docs/topics/release-notes.md
	rest_framework/authentication.py
	rest_framework/serializers.py
	rest_framework/templatetags/rest_framework.py
	rest_framework/tests/test_authentication.py
	rest_framework/tests/test_filters.py
	rest_framework/tests/test_hyperlinkedserializers.py
	rest_framework/tests/test_serializer.py
	rest_framework/tests/test_testing.py
	rest_framework/utils/encoders.py
	tox.ini

1 files changed, 25 insertions, 0 deletions

diff --git a/rest_framework/tests/utils.py b/rest_framework/tests/utils.py
new file mode 100644
index 00000000..a8f2eb0b
--- /dev/null
+++ b/rest_framework/tests/utils.py
@@ -0,0 +1,25 @@
+from contextlib import contextmanager
+from rest_framework.compat import six
+from rest_framework.settings import api_settings
+
+
+@contextmanager
+def temporary_setting(setting, value, module=None):
+    """
+    Temporarily change value of setting for test.
+
+    Optionally reload given module, useful when module uses value of setting on
+    import.
+    """
+    original_value = getattr(api_settings, setting)
+    setattr(api_settings, setting, value)
+
+    if module is not None:
+        six.moves.reload_module(module)
+
+    yield
+
+    setattr(api_settings, setting, original_value)
+
+    if module is not None:
+        six.moves.reload_module(module)