additional sanity checks. git-svn-id: http://simplesamlphp.googlecode.com/svn/trunk@622 44740490-163a-0410-bde0-09ae8108e29a
git-svn-id: http://simplesamlphp.googlecode.com/svn/trunk@534 44740490-163a-0410-bde0-09ae8108e29a