Set default branchname on first push (#3715)

Author: Bwko

models/action.go

@@ -523,6 +523,11 @@ func CommitRepoAction(opts CommitRepoActionOptions) error {
 		return fmt.Errorf("GetRepositoryByName [owner_id: %d, name: %s]: %v", opts.RepoOwnerID, opts.RepoName, err)
 	}
 
+	refName := git.RefEndName(opts.RefFullName)
+	if repo.IsBare && refName != repo.DefaultBranch {
+		repo.DefaultBranch = refName
+	}
+
 	// Change repository bare status and update last updated time.
 	repo.IsBare = repo.IsBare && opts.Commits.Len <= 0
 	if err = UpdateRepository(repo, false); err != nil {
@@ -563,7 +568,6 @@ func CommitRepoAction(opts CommitRepoActionOptions) error {
 		return fmt.Errorf("Marshal: %v", err)
 	}
 
-	refName := git.RefEndName(opts.RefFullName)
 	if err = NotifyWatchers(&Action{
 		ActUserID: pusher.ID,
 		ActUser:   pusher,