recountdiff
The corrected diff is sent to standard output.
--help
--version
There are some things that cannot be dealt with. If you have removed the first context line in a hunk, for example, there is no way for recountdiff to know that. For more precise fixing up, use rediff(1), which uses the original and modified diffs.
rediff(1)
Tim Waugh <twaugh@redhat.com>