Fix RequestContext crashes w/ no service catalog

Code introduced in a prev review assumed service_catalog will be
at least an empty list and will never be None.  But missed one code
path where the service_catalog could potentially be set to None. So
this change switches back the default value of service_catalog in
the arguments to None and makes sure we tolerate anyone else
passing in a None or Empty list as service_catalog

Fix for LP# 1156730

Change-Id: I480b761d57c4699ea7ef72114160cdbeb281e454

1 files changed, 9 insertions, 3 deletions

diff --git a/nova/context.py b/nova/context.py
index 714948e90..cd4428e58 100644
--- a/nova/context.py
+++ b/nova/context.py
@@ -47,7 +47,7 @@ class RequestContext(object):
                  roles=None, remote_address=None, timestamp=None,
                  request_id=None, auth_token=None, overwrite=True,
                  quota_class=None, user_name=None, project_name=None,
-                 service_catalog=[], instance_lock_checked=False, **kwargs):
+                 service_catalog=None, instance_lock_checked=False, **kwargs):
         """
         :param read_deleted: 'no' indicates deleted records are hidden, 'yes'
             indicates deleted records are visible, 'only' indicates that
@@ -77,9 +77,15 @@ class RequestContext(object):
             request_id = generate_request_id()
         self.request_id = request_id
         self.auth_token = auth_token
-        # Only include required parts of service_catalog
-        self.service_catalog = [s for s in service_catalog
+
+        if service_catalog:
+            # Only include required parts of service_catalog
+            self.service_catalog = [s for s in service_catalog
                 if s.get('type') in ('volume')]
+        else:
+            # if list is empty or none
+            self.service_catalog = []
+
         self.instance_lock_checked = instance_lock_checked
 
         # NOTE(markmc): this attribute is currently only used by the