Unregistered users cannot download multiple files (package) on Tomcat

[mflorea]

The server returns a 400 Bad Request for the download URL. The download URLs look like this:

// Registered user
http://localhost:8080/xwiki/bin/get/FileManager/Download-Admin-NAhd (302 Redirect)
http://localhost:8080/xwiki/tmp/filemanager/document%3Axwiki%3AFileManager.Download-Admin-NAhd/NAhd.zip

// Unregistered user
http://localhost:8080/xwiki/bin/get/FileManager/Download-%24%7Bxcontext.userReference.name%7D-gkub (302 Redirect)
http://localhost:8080/xwiki/tmp/filemanager/document%3Axwiki%3AFileManager.Download-%24%7Bxcontext%21.userReference%21.name%7D-gkub/gkub.zip

Notice the $xcontext.userReference.name in the download URL for unregistered users. The reason is because the guest user reference is null. The Tomcat doesn't like the encoded $ character. It works fine with Jetty though. Note that the URL is properly URL-encoded but Tomcat is protected itself from some security issues and doesn't allow such an URL.

We can use Velocity's silent notation to prevent this problem.