It's been a while since I've touched that code, but AFAIR the queryParams field is used to set additional query params, not to retrieve those associated with the current request.

On 23 February 2016 at 07:32, Thomas Darimont <thomas.darimont@googlemail.com> wrote:
Sorry was probably to late for me yesterday...

I was trying to add dynamic theme selection via URL parameter - and I noticed that a "theme" 
parameter passed to the login URL was not propagated to FreeMarkerLoginFormsProvider. 

I needed to be able to dynamically select a theme for the login site with a parameter:
https://gist.github.com/thomasdarimont/c59acdd7d7d41fd5c041#file-freemarkerloginformsprovider-java-L201

Cheers,
Thomas