Import seperate git repo as subdirectory

gistfile1.sh

export target=my_dir
git remote add "$target" file:////path/to/original/repo
git fetch "$target"
git co -b "$target" "$target/master"
# Probably breaks on whitespace, sorry dawg.
git filter-branch -f --tree-filter "mkdir -p \"$target\"; git ls-tree \$GIT_COMMIT --name-only | xargs --no-run-if-empty mv -t $target" "$target"
git co master
git merge "$target"
git remote remove "$target"
git br -d "$target"