Only reverse adjust the changes in the commit, which means that adjustments
do not need to be generally cleanly reversable.
For example, an adjustment can unlock all locked files, but does not need
to worry about files that were originally unlocked when reversing, because
it will only ever be run on files that have been changed. So, it's ok
if it locks all files when reversed, or even leaves all files as-is when
reversed.
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