in spec/repository_spec.rb [1137:1152]
def new_commit_edit_old_file(repo)
oid = repo.write("I replaced the changelog with this text", :blob)
index = repo.index
index.read_tree(repo.head.target.tree)
index.add(path: "CHANGELOG", oid: oid, mode: 0100644)
options = commit_options(
repo,
index,
"Edit CHANGELOG in its original location"
)
sha = Rugged::Commit.create(repo, options)
repo.lookup(sha)
end