Rendering of relative Urls does not take into account filterpath for absolute Urls

Assume, there is an WicketApplication with mounted Page "error" running on https://localhost:8443/ 

The page "error" renders an reference for resource "https://localhost:8443/webjars/uilib/5.6.0/javascripts/bundle.all.js". The rendered Url is created by Url.parse("https://localhost:8443/webjars/uilib/5.6.0/javascripts/bundle.all.js").

In this case everything is fine:

https://localhost:8443/error renders tag <script type="text/javascript" src="./webjars/uilib/5.6.0/javascripts/bundle.all.js"></script>

But if I change the filterpath of the application to "recovery", the following happens:

https://localhost:8443/recovery/error renders tag <script type="text/javascript" src=".//webjars/uilib/5.6.0/javascripts/bundle.all.js"></script>

This is not the expected value "../webjars/uilib/5.6.0/javascripts/bundle.all.js" of the src-Attribute.

I tried to break it down: The rendered Url in the script tag is created by the UrlRenderer. The UrlRenderer decides to render a relative url as scheme, host and port match the corresponding properties of the clientUrl and the Url is not "contextabsolute" (as it contains an hostname). I think, this is absolutly fine. But during rendering the relative url the UrlRenderer does not detect, that it has to handle this url separatly. The segments of the Url contain a leading "" (for /) which is not followed by the filterpath. I assume, this should be resolved to ".." for every part of the filterpath.