Avoid {} and [] as default arguments

Dict and list objects are mutable and are usually the sources of
subtle bugs when used as default arguments. Avoid them.

Change-Id: I5340c7051455a80c4adfab885d89acb46570fa52

1 files changed, 7 insertions, 2 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index f818e7685..14e84fa1b 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -800,10 +800,15 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @wrap_instance_fault
     def run_instance(self, context, request_spec=None,
-                     filter_properties={}, requested_networks=None,
-                     injected_files=[], admin_password=None,
+                     filter_properties=None, requested_networks=None,
+                     injected_files=None, admin_password=None,
                      is_first_time=False, instance=None, instance_uuid=None):
 
+        if filter_properties is None:
+            filter_properties = {}
+        if injected_files is None:
+            injected_files = []
+
         if not instance_uuid:
             instance_uuid = instance['uuid']