add 'debugrebuildstate' to rebuild the dirstate from a given revision - added and removed files will be lost while recreating the dirstate - modifications are not lost

#!/bin/sh

mkdir a
cd a
hg init
echo foo > b
hg add b
hg ci -m "b" -d "0 0"

chmod -w .hg

cd ..

hg clone a b

chmod +w a/.hg # let test clean up

cd b
hg verify