I tried to comment on a bug I reported today (MDL-6641), but got a Java stack trace starting
java.lang.IllegalArgumentException: Custom field with id 'customfield_10012' does not exist.
I wanted to say that the /lib/setup.php reads $lang from optional_param('lang', PARAM_SAFEDIR and then sets this to the $SESSION->lang which makes the language edits a bit too sticky from course edit and profile edit forms. (added this text here as I'll forget it after "Post to forum" as usually
