Author: Marina Glancy
MDL-39177 File reference is not updated when overwriting the file
http://git.moodle.org/gw?p=moodle.git;a=commit;h=e9e32b1d8815531f4d66907b063da84b41a5ea45
http://github.com/moodle/moodle/commit/e9e32b1d8815531f4d66907b063da84b41a5ea45
+ 2.6 en [errordoublereference,core_repository]