git-update-index --refresh 2>/dev/null
new_head=$(git-rev-parse --verify "$1^0") &&
git-read-tree -u -v -m $head "$new_head" &&
git-update-index --refresh 2>/dev/null
new_head=$(git-rev-parse --verify "$1^0") &&
git-read-tree -u -v -m $head "$new_head" &&