Making a request for a deleted attachment with a wrong rid from a created page causes NPE

STEPS TO REPRODUCE

1. Create a page (e.g. on root, named TestPage)
2. Upload a file and then delete it
3. Make a request for it from the recycle bin using a non-existent rid parameter in the query string (ex: /xwiki/bin/downloadrev/TestPage/yourfile.jpg?rev=1.1&rid=144)

EXPECTED RESULTS

An error is displayed informing that the respective attachment does not exist.

ACTUAL RESULTS

A NullPointerException is displayed.

However, if the file is uploaded inside Sandbox Application pages (e.g. Sandbox.WebHome or Sandbox.TestPage1) the correct error is displayed.