Author: Ankit Kumar Agarwal
MDL-29619 Validate urls before generating output
http://git.moodle.org/gw?p=moodle.git;a=commit;h=8077c81f47b38e364941846199a71b58124cb4fb
http://github.com/moodle/moodle/commit/8077c81f47b38e364941846199a71b58124cb4fb
+ 2.2 en [invalidstoredurl,mod_url]