dirstate.status: if a file is marked as copied, consider it modified
After a "hg copy --force --after somefile cleanfile", cleanfile
shouldn't be considered clean anymore.
#!/bin/sh
hg init a
echo a > a/a
hg --cwd a ci -A -m a
hg clone a b
echo b > b/b
hg --cwd b ci -A -m b
chmod 100 a/.hg/store
hg --cwd b push ../a
chmod 700 a/.hg/store