I would assume browser can see if favicon name is the same.If it is it won't request its download again and will use one already cached, but if you change the name it will assume it has changed thus requesting it from the server.It's easier and just as effective to use the file's last modified date.I see no advantage of using the MD5 over the last modified stamp.This way the Favicon will always refresh when it has been changed.
Assuming that you've defined your icon via I recently restored my bookmarks and was looking for a way to restore the Fav Icons without visiting each page. For those in a similar circumstance merely download the FAVICON RELOADER addon.
I have a Grails application running locally using its own tomcat and I have just changed the favicon for a new one. The old favicon shows up or I get no favicon at all, but not my new one. I have numerous bookmarks in my browser which have the wrong icons and they never seem to get refreshed.
I don't think this is a Grails issue per se, more an issue wth favicons. How do I force the server/browser to stop cacheing them?
I wrote this answer under the impression that this is what it took to refresh favicons in Google Chrome.
However, it turns out that this only works for the first five minutes or so, until the icon gets irretrievably lost in Chrome's history synchronization.