tests/test-undo

contrib: add Chris Mason's stand-alone diff tool

This uses Mercurial's diff algorithm to generate unidiffs like the traditional diff tool.

#!/bin/sh

mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m "test" -d "0 0"
hg verify
hg parents
hg status
hg undo
hg verify
hg parents
hg status