How to get the current branch with LibGit2Sharp?

Question

How do I get the branch for a specific directory even if this directory is not the root of the repo ? iow the equivalent of

git branch --show-current

(which works fine even in a subdirectory).

Following the answer to this similar question, I did as follows, which works only in the root dir of the repo:

using (var git = new Repository("repo_root\subdir")) // throws if subdir
{
  return git.Head.FriendlyName;
}

Answer 1

Oops, found it:

using (var git = new Repository(
  LibGit2Sharp.Repository.Discover(@"repo_root\subdir")))
{
  return git.Head.FriendlyName;
}