Pushing new branches does not set up tracking branch completely

When you push a local branch that does not exist on the remote (using the refspec overload), libgit2sharp automatically creates a tracking branch, but it does not set up the config for the local branch

i.e. the following config entries are missing:

branch.(branch_name).remote
branch.(branch_name).merge

Currently, I push a new branch like as follows:

string refspec = string.Format("{0}:{1}",
    currentBranch.CanonicalName, currentBranch.CanonicalName);
repo.Network.Push(remote, refspec, handler, credentials);
repo.Branches.Update(repo.Head, delegate(BranchUpdater updater)
{
    updater.Remote = remote.Name;
    updater.UpstreamBranch = repo.Head.CanonicalName;
});

I feel like this should be simplified. Either by doing the BranchUpdater stuff in Push(), or by extending the Push(Branch, ...) overload to let it accept non-tracking branches and do the whole process.

I also did not find a test fixture covering that feature, so the intended behaviour should at least be specified.

先閱讀 issue 中展示的 Push 多載和 BranchUpdater 的使用方式，然後檢查現有的 push 測試 fixture，因為 issue 表示沒有任何 fixture 涵蓋此行為。完成的標準是，受支援的新分支 push 路徑能夠建立 branch.remote 和 branch.merge 設定，並有一個測試明確指定預期行為。