The query string is lost when exporting a document as PDF

Documents that output different things based on the query string parameters are not properly exported. To reproduce, create a document with this content:

{{velocity}}
My favorite color is $request.color!
{{/velocity}}

then specify the color in the query string (/xwiki/bin/view/Test/Page?color=green) and try to export the page as PDF or try to preview the print.