'test_chmod +x rezrov &&
git diff-index $tree >current'
-_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
-_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
sed -e 's/\(:100644 100755\) \('"$_x40"'\) \2 /\1 X X /' <current >check
echo ":100644 100755 X X M rezrov" >expected