fix default initial branch ignoring the project default branch and always be set to master

fs/repository.go

@@ -29,7 +29,7 @@ func newRepositoryNode(project *gitlab.Project, param *FSParam) (*RepositoryNode
 
 func (n *RepositoryNode) Readlink(ctx context.Context) ([]byte, syscall.Errno) {
 	// Create the local copy of the repo
-	localRepoLoc, _ := n.param.Git.CloneOrPull(n.project.CloneURL, n.project.ID, "master")
+	localRepoLoc, _ := n.param.Git.CloneOrPull(n.project.CloneURL, n.project.ID, n.project.DefaultBranch)
 
 	return []byte(localRepoLoc), 0
 }

git/clone.go

@@ -82,9 +82,12 @@ func (c *gitClient) clone(gcp *gitCloneParam) error {
 		if err != nil {
 			return fmt.Errorf("failed to retrieve worktree of git repo %v: %v", gcp.dst, err)
 		}
-		w.Checkout(&git.CheckoutOptions{
+		err = w.Checkout(&git.CheckoutOptions{
 			Branch: branchRef,
 		})
+		if err != nil {
+			return fmt.Errorf("failed to checkout %v of git repo %v: %v", branchRef, gcp.dst, err)
+		}
 	}
 	if c.PullAfterClone {
 		// Dispatch to pull worker

gitlab/project.go

@@ -8,6 +8,7 @@ type Project struct {
 	ID            int
 	Name          string
 	CloneURL      string
+	DefaultBranch string
 }
 
 func (c *gitlabClient) newProjectFromGitlabProject(project *gitlab.Project) Project {
@@ -15,6 +16,10 @@ func (c *gitlabClient) newProjectFromGitlabProject(project *gitlab.Project) Proj
 	p := Project{
 		ID:            project.ID,
 		Name:          project.Path,
+		DefaultBranch: project.DefaultBranch,
+	}
+	if p.DefaultBranch == "" {
+		p.DefaultBranch = "master"
 	}
 	if c.PullMethod == PullMethodSSH {
 		p.CloneURL = project.SSHURLToRepo