The return URL that is part of the link to CAS login is double-escaped on the staff login page.
It appears that this is the same issue as bug 21973 but in the staff intranet template. I have attached an identical patch for the intranet auth.tt file.
Signed-off-by: Nick Clemens <nick@bywatersolutions.com> Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de> Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>