That’s correct. It seems to ignore the domain and only uses the path even when the other wiki domain has been added to url.trustedDomains in xwiki.properties. When it is specified it doesn’t show errors in the logs about an untrusted domain, it does show the error when it isn’t specified.
I’ve also tried url.trustedDomainsEnabled set to false, but it still uses the current wiki’s domain.
I haven’t tested setting a redirect to an address outside of our wiki yet. I’ll try that and come back.