Steps to reproduce

1. Import Site configuration and website workspace as attached
2. Create a Text/Image Component in SiteA
3. Push the changes to SiteB
4. Protect all the headline fields of the pushed component
5. Look into the jcr of the component and check the property propertiesToIgnore
6. Delete the defaultLocale property from the site config of pageB
7. Delete the propertiesToIgnore property of the component
8. Protect the headline fields again
9. Look again into the jcr of the component

Expected results

I would expect that the defaultLocale has no impact on the behavior of field protection. 

Actual results

As you can see on the Screenshot, when the defaultLocale is set, the wrong fieldKey is protected.

With default locale:

Without defaultLocale:

Workaround

Development notes