pkg/vcs: fix fetching of commits on non master branch

Fixes #728

2 files changed, 173 insertions, 2 deletions

diff --git a/pkg/vcs/git.go b/pkg/vcs/git.go
index bc0e05373..f73c47c58 100644
--- a/pkg/vcs/git.go
+++ b/pkg/vcs/git.go
@@ -16,6 +16,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/google/syzkaller/pkg/hash"
 	"github.com/google/syzkaller/pkg/osutil"
 )
 
@@ -87,13 +88,20 @@ func (git *git) CheckoutCommit(repo, commit string) (*Commit, error) {
 			return nil, err
 		}
 	}
-	_, err := runSandboxed(dir, "git", "fetch", repo)
-	if err != nil {
+	if err := git.fetchRemote(repo); err != nil {
 		return nil, err
 	}
 	return git.SwitchCommit(commit)
 }
 
+func (git *git) fetchRemote(repo string) error {
+	repoHash := hash.String([]byte(repo))
+	// Ignore error as we can double add the same remote and that will fail.
+	runSandboxed(git.dir, "git", "remote", "add", repoHash, repo)
+	_, err := runSandboxed(git.dir, "git", "fetch", repoHash)
+	return err
+}
+
 func (git *git) SwitchCommit(commit string) (*Commit, error) {
 	dir := git.dir
 	if _, err := runSandboxed(dir, "git", "checkout", commit); err != nil {
diff --git a/pkg/vcs/git_repo_test.go b/pkg/vcs/git_repo_test.go
new file mode 100644
index 000000000..e6f94c117
--- /dev/null
+++ b/pkg/vcs/git_repo_test.go
@@ -0,0 +1,163 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package vcs
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/syzkaller/pkg/osutil"
+)
+
+func TestGitRepo(t *testing.T) {
+	baseDir, err := ioutil.TempDir("", "syz-git-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(baseDir)
+	repo1 := createTestRepo(t, baseDir, "repo1")
+	repo2 := createTestRepo(t, baseDir, "repo2")
+	repo := newGit(filepath.Join(baseDir, "repo"))
+	{
+		com, err := repo.Poll(repo1.dir, "master")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if diff := cmp.Diff(com, repo1.commits["master"]["1"]); diff != "" {
+			t.Fatal(diff)
+		}
+	}
+	{
+		com, err := repo.CheckoutBranch(repo1.dir, "branch1")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if diff := cmp.Diff(com, repo1.commits["branch1"]["1"]); diff != "" {
+			t.Fatal(diff)
+		}
+	}
+	{
+		want := repo1.commits["branch1"]["0"]
+		com, err := repo.CheckoutCommit(repo1.dir, want.Hash)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if diff := cmp.Diff(com, want); diff != "" {
+			t.Fatal(diff)
+		}
+	}
+	{
+		commits, err := repo.ListRecentCommits(repo1.commits["branch1"]["1"].Hash)
+		if err != nil {
+			t.Fatal(err)
+		}
+		want := []string{"repo1-branch1-1", "repo1-branch1-0", "repo1-master-0"}
+		if diff := cmp.Diff(commits, want); diff != "" {
+			t.Fatal(diff)
+		}
+	}
+	{
+		want := repo2.commits["branch1"]["0"]
+		com, err := repo.CheckoutCommit(repo2.dir, want.Hash)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if diff := cmp.Diff(com, want); diff != "" {
+			t.Fatal(diff)
+		}
+	}
+	{
+		want := repo2.commits["branch1"]["1"]
+		com, err := repo.CheckoutCommit(repo2.dir, want.Hash)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if diff := cmp.Diff(com, want); diff != "" {
+			t.Fatal(diff)
+		}
+	}
+	{
+		com, err := repo.CheckoutBranch(repo2.dir, "branch2")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if diff := cmp.Diff(com, repo2.commits["branch2"]["1"]); diff != "" {
+			t.Fatal(diff)
+		}
+	}
+	{
+		want := repo2.commits["branch2"]["0"]
+		com, err := repo.SwitchCommit(want.Hash)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if diff := cmp.Diff(com, want); diff != "" {
+			t.Fatal(diff)
+		}
+	}
+}
+
+func createTestRepo(t *testing.T, baseDir, name string) *testRepo {
+	repo := makeTestRepo(t, filepath.Join(baseDir, name))
+	repo.git("checkout", "-b", "master")
+	repo.commitFileChange("master", "0")
+	for _, branch := range []string{"branch1", "branch2"} {
+		repo.git("checkout", "-b", branch, "master")
+		repo.commitFileChange(branch, "0")
+		repo.commitFileChange(branch, "1")
+	}
+	repo.git("checkout", "master")
+	repo.commitFileChange("master", "1")
+	return repo
+}
+
+type testRepo struct {
+	t       *testing.T
+	dir     string
+	name    string
+	commits map[string]map[string]*Commit
+}
+
+func makeTestRepo(t *testing.T, dir string) *testRepo {
+	if err := osutil.MkdirAll(dir); err != nil {
+		t.Fatal(err)
+	}
+	repo := &testRepo{
+		t:       t,
+		dir:     dir,
+		name:    filepath.Base(dir),
+		commits: make(map[string]map[string]*Commit),
+	}
+	repo.git("init")
+	return repo
+}
+
+func (repo *testRepo) git(args ...string) {
+	if _, err := osutil.RunCmd(time.Minute, repo.dir, "git", args...); err != nil {
+		repo.t.Fatal(err)
+	}
+}
+
+func (repo *testRepo) commitFileChange(branch, change string) {
+	id := fmt.Sprintf("%v-%v-%v", repo.name, branch, change)
+	file := filepath.Join(repo.dir, "file")
+	if err := osutil.WriteFile(file, []byte(id)); err != nil {
+		repo.t.Fatal(err)
+	}
+	repo.git("add", file)
+	repo.git("commit", "-m", id)
+	if repo.commits[branch] == nil {
+		repo.commits[branch] = make(map[string]*Commit)
+	}
+	com, err := newGit(repo.dir).HeadCommit()
+	if err != nil {
+		repo.t.Fatal(err)
+	}
+	repo.commits[branch][change] = com
+}