I wish vi were more graceful when a file system is full

[Jim Haynes]

We all run systems with the disks 99% full 99% of the time don't we?
Or maybe the problem is that they are only 90% full most of the time.
Anyway, our semi-naive users have a fair amount of trouble when
they try to edit, and some jerk has filled up the file system, and
then they can't write the edited file back.  Those in the know
have learned to write to /tmp or /usr/tmp or some other place that
is safe for parking files; but most of them the first time manage to
lose both the edited file and the unedited file and come to me in tears.

So has anybody patched vi to give the user some kind of helpful
message suggesting what to do when the file cannot be written
because the file system is full?