v4.5.12 relative URLs don't resolve to the host endpoint?

Upgraded our app from v4.5.8 to v.4.5.12, and I noticed that redirects to a relative URL are now routed differently.

Our ServiceStack endpoint base is /some/path/api

Our app host is configured to redirect from the base to a documentation page:

Config.DefaultRedirectPath = "docs/reference.html";
v4.5.8  redirects `GET /some/path/api` to `/some/path/api/docs/reference.html` (Yay!)
v4.5.12 redirects `GET /some/path/api` to `/docs/reference.html` (Boo!)
// Same effect, redirecting to the host root instead of relative to the endpoint base. 
Config.DefaultRedirectPath = "~/docs/reference.html";

Is there a way I can work around this and ask an AppHost for its base Url?

Config.DefaultRedirectPath = MagicallyGetMyEndpointBaseUrl() + "/docs/reference.html";

Config.WebHostUrl is null, so I can’t use that.

Any ideas?

We may have fixed this URL resolution issue with the latest v4.5.13 on MyGet, or if you prefer can you copy the GetBaseUrl impl from AppHostBase and let me know if that resolves the issue? Also URLs should ideally start with ~/ or /.