Output filters

I have been scouring the source for Smarty trying to find how to read the currently parsed tpl from the output filter, without enabling debug mode, is there a reason this isn't currently possible and would a patch to be able to do it be accepted? Right now i'm making a htmltidy output filter that logs (emails?) when there is bad html output from a template so as I can slowly repair some horrid html i'v had thrown at me however I can't always tell what tpl is the 'master' generating the mess with just the request uri. Alternative suggestions welcomed if anyone has a better idea on how to do this. Cameron