The 'undofile'
is a great feature, and I use it a lot. However, one annoyance
is that it's very easy to accidentally undo changes that I did the last time I
opened the file; which may be 2 minutes ago, an hour ago, last week, or a
month ago.
So what would happen is that sometimes I would accidentally undo changes from
ages ago.
This plugin fixes that by showing a warning.
I originally posted this as an answer on vi StackExchange, which also has some other solutions to the same problem: http://vi.stackexchange.com/q/2115/51