skip identical doesn't work with version id

[clayg]

vagrant@saio:~$ swift stat test test.big | grep ETag
                  ETag: "e90bdd237cc57f1b8308fcadf8f50f06"
vagrant@saio:~$ swift stat test test.big --version-id 1714404624.45423 | grep ETag
                  ETag: "cac0f63d4c7cfc6a4abdcb06b382e465"
vagrant@saio:~$ swift download test test.big -o delete.me
test.big [auth 0.006s, headers 0.076s, total 0.150s, 23.675 MB/s]
vagrant@saio:~$ swift download test test.big -o delete.me --skip-identical
Skipped identical file 'test.big'
vagrant@saio:~$ swift download test test.big -o delete.me --skip-identical --version-id 1714404624.45423
Skipped identical file 'test.big'

What seems to be going on is if-none-match request always sends the qs ?multipart-manifest=get and drops the &version-id=

https://github.com/openstack/python-swiftclient/blob/master/swiftclient/service.py#L1228-L1235

this means the "is identical" comparison always happens against the local file-name whatever that is and the "current" version stored in the bucket.

FWIW --skip-identical is mostly only used when downloading whole containers/prefixes and --version-id explicitly is only allowed for use with a single object - so I'm not sure how often people run into this use-case in practice. I only noticed it while reviewing something else [1]

1. 902020: support part-num in python swiftClient | https://review.opendev.org/c/openstack/python-swiftclient/+/902020