S3 suffix-range GET on a zero-byte object returns private NotPartial wrapped as Error::Generic #846

Describe the bug

Requesting a suffix range from an existing zero-byte S3 object fails with Error::Generic(GetResultError::NotPartial). S3 returns a 200 for the suffix-range GET when the object is 0 bytes, but object_store expects a 206.

To Reproduce

  let options =
      GetOptions::new().with_range(Some(GetRange::Suffix(512 * 1024)));
  let result = store.get_opts(&path, options).await;

For a zero-byte object, AWS S3 responds with:

  HTTP/1.1 200 OK
  Content-Length: 0

Expected behavior
Either the call should return success, or fail with some error with a specific type that the caller can use to discriminate and handle this case specifically (e.g. by falling back to a HEAD).