I've never seen a browser do this. It's not clear to me it's a good idea, considering how widely input fields are used behind the scenes. Websites can request t

I've never seen a browser do this. It's not clear to me it's a good idea, considering how widely input fields are used behind the scenes. Websites can request that the browser ask before navigating away, but I don't think a browser could reasonably do this automatically without getting it wrong annoyingly often.