Merge pull request #134 from troyready/fix_104

Remove hardcoded master branch reference

Author: azr

get_git.go

@@ -1,6 +1,7 @@
 package getter
 
 import (
+	"bytes"
 	"context"
 	"encoding/base64"
 	"fmt"
@@ -9,6 +10,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"strconv"
 	"strings"
@@ -24,6 +26,8 @@ type GitGetter struct {
 	getter
 }
 
+var defaultBranchRegexp = regexp.MustCompile(`\s->\sorigin/(.*)`)
+
 func (g *GitGetter) ClientMode(_ *url.URL) (ClientMode, error) {
 	return ClientModeDir, nil
 }
@@ -182,10 +186,10 @@ func (g *GitGetter) update(ctx context.Context, dst, sshKeyFile, ref string, dep
 	cmd.Dir = dst
 
 	if getRunCommand(cmd) != nil {
-		// Not a branch, switch to master. This will also catch non-existent
-		// branches, in which case we want to switch to master and then
-		// checkout the proper branch later.
-		ref = "master"
+		// Not a branch, switch to default branch. This will also catch
+		// non-existent branches, in which case we want to switch to default
+		// and then checkout the proper branch later.
+		ref = findDefaultBranch(dst)
 	}
 
 	// We have to be on a branch to pull
@@ -216,6 +220,22 @@ func (g *GitGetter) fetchSubmodules(ctx context.Context, dst, sshKeyFile string,
 	return getRunCommand(cmd)
 }
 
+// findDefaultBranch checks the repo's origin remote for its default branch
+// (generally "master"). "master" is returned if an origin default branch
+// can't be determined.
+func findDefaultBranch(dst string) string {
+	var stdoutbuf bytes.Buffer
+	cmd := exec.Command("git", "branch", "-r", "--points-at", "refs/remotes/origin/HEAD")
+	cmd.Dir = dst
+	cmd.Stdout = &stdoutbuf
+	err := cmd.Run()
+	matches := defaultBranchRegexp.FindStringSubmatch(stdoutbuf.String())
+	if err != nil || matches == nil {
+		return "master"
+	}
+	return matches[len(matches)-1]
+}
+
 // setupGitEnv sets up the environment for the given command. This is used to
 // pass configuration data to git and ssh and enables advanced cloning methods.
 func setupGitEnv(cmd *exec.Cmd, sshKeyFile string) {

get_git_test.go

@@ -88,6 +88,44 @@ func TestGitGetter_branch(t *testing.T) {
 	}
 }
 
+func TestGitGetter_remoteWithoutMaster(t *testing.T) {
+	if !testHasGit {
+		t.Log("git not found, skipping")
+		t.Skip()
+	}
+
+	g := new(GitGetter)
+	dst := tempDir(t)
+
+	repo := testGitRepo(t, "branch")
+	repo.git("checkout", "-b", "test-branch")
+	repo.commitFile("branch.txt", "branch")
+
+	q := repo.url.Query()
+	repo.url.RawQuery = q.Encode()
+
+	if err := g.Get(dst, repo.url); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Verify the main file exists
+	mainPath := filepath.Join(dst, "branch.txt")
+	if _, err := os.Stat(mainPath); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Get again should work
+	if err := g.Get(dst, repo.url); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Verify the main file exists
+	mainPath = filepath.Join(dst, "branch.txt")
+	if _, err := os.Stat(mainPath); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+}
+
 func TestGitGetter_shallowClone(t *testing.T) {
 	if !testHasGit {
 		t.Log("git not found, skipping")
@@ -380,6 +418,7 @@ func TestGitGetter_sshExplicitPort(t *testing.T) {
 	}
 }
 
+
 func TestGitGetter_sshSCPStyleInvalidScheme(t *testing.T) {
 	if !testHasGit {
 		t.Skip("git not found, skipping")