filter scheduler raises TypeError: argument of type 'NoneType' is not iterable when placement returns no allocation candidates

[Balazs Gibizer]

Building on top of the 'claim resources in placement API during schedule()' patch series [1] I tried to consume every resources available. When the placement API return no allocation candidates as there is no resources left the scheduler/manager blows up with a stack trace [2].

It seems that problem is introduces in [3]. The effect is not severe as the exception fails the scheduling which is the expected behavior when there is no resources left.

[1] https://review.openstack.org/#/c/483566
[2] http://paste.openstack.org/show/616000/
[3] https://review.openstack.org/#/c/483565/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/485585

[OpenStack Infra (hudson-openstack)]

Change abandoned by Balazs Gibizer (<email address hidden>) on branch: master
Review: https://review.openstack.org/485585
Reason: Let's fix it in https://review.openstack.org/#/c/483566/

[Matt Riedemann (mriedem)]

I'm going to mark this as invalid given it's a bug against an in-review change, so we'll get it fixed in:

https://review.openstack.org/#/c/483566/