Comment 1 for bug 1815153

I'm not sure but another case this could affect is rebuilding with a new image, in which case the API sets the new image on the request spec:

https://github.com/openstack/nova/blob/a6963fa6858289d048e4d27ce8e61637cd023f4c/nova/compute/api.py#L3323

Although I guess we intentionally save that change so it's probably OK. Plus this:

https://github.com/openstack/nova/blob/a6963fa6858289d048e4d27ce8e61637cd023f4c/nova/compute/api.py#L3329

Should make any save() later fail - although that's probably worth investigating if the request spec is old and would blow up on save() here:

https://github.com/openstack/nova/blob/a6963fa6858289d048e4d27ce8e61637cd023f4c/nova/conductor/manager.py#L1009