List Properties return None by default

[Steven Hardy]

List properties, and probably also map, return None by default, which is inconvenient if you want to iterate over a property as you have to remember to default to an empty list either in the schema or when getting the property.

This is inconvenient and error prone, and can easily result in a 'NoneType' object is not iterable error when people forget.

It may be better, long term, to default these in the top-level Property class, Zane has suggested we need to do an audit of all existing uses of these type of properties to ensure nothing breaks.

[Zane Bitter (zaneb)]

Everything returns None by default.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/59092

[Angus Salkeld (asalkeld)]

this may help too: https://review.openstack.org/#/c/124943/2

[Pradeep Kumar Singh (pradeep-singh-u)]

Hi Angus,

I think this issue does not exists any more, am i right?

[Zane Bitter (zaneb)]

Yeah, it looks to me like the change in comment #3 would have resolved this. Hopefully it didn't break too much stuff...