How to highlight lines changed since the last save of a file in Vim?

vim

Solution

Straight from Vim documentation (see `:help :DiffOrig`):

if !exists(":DiffOrig")
    command DiffOrig vert new | set bt=nofile | r # | 0d_ | diffthis
          \ | wincmd p | diffthis
endif

Then just do `:DiffOrig` et voila!

Problem

Is it possible to have Vim highlight the changed lines since the last save? I know it can be done with version control, but can it be done without? I do not want to use any version control system, because the code I work on does not have that. I think, UltraEdit has something like that.

Original source

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