Automatic merge from submit-queue (batch tested with PRs 66011, 66111, 66106, 66039, 65745). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
fieldpath: Add tests for missing cases
Tests some missing cases in `pkg/fieldpath`.
**Release note**:
```release-note
NONE
```
Signed-off-by: Lorenzo Fontana <lo@linux.com>