Merge branch 'fetch_remote_default_branch' into 'master'

Set default branch to match remote for FetchInternalRemote

Closes #2837

See merge request gitlab-org/gitaly!2265

5 files changed, 78 insertions, 3 deletions

diff --git a/changelogs/unreleased/fetch_remote_default_branch.yml b/changelogs/unreleased/fetch_remote_default_branch.yml
new file mode 100644
index 000000000..3da75c753
--- /dev/null
+++ b/changelogs/unreleased/fetch_remote_default_branch.yml
@@ -0,0 +1,5 @@
+---
+title: Set default branch to match remote for FetchInternalRemote
+merge_request: 2265
+author:
+type: fixed
diff --git a/internal/service/ref/refs.go b/internal/service/ref/refs.go
index 0618a7ac3..c4a8e831f 100644
--- a/internal/service/ref/refs.go
+++ b/internal/service/ref/refs.go
@@ -206,6 +206,18 @@ func _headReference(ctx context.Context, repo *gitalypb.Repository) ([]byte, err
 	return headRef, nil
 }
 
+// SetDefaultBranchRef overwrites the default branch ref for the repository
+func SetDefaultBranchRef(ctx context.Context, repo *gitalypb.Repository, ref string) error {
+	cmd, err := git.SafeCmd(ctx, repo, nil, git.SubCmd{
+		Name: "symbolic-ref",
+		Args: []string{"HEAD", ref},
+	})
+	if err != nil {
+		return err
+	}
+	return cmd.Wait()
+}
+
 // DefaultBranchName looks up the name of the default branch given a repoPath
 func DefaultBranchName(ctx context.Context, repo *gitalypb.Repository) ([]byte, error) {
 	branches, err := FindBranchNames(ctx, repo)
diff --git a/internal/service/ref/refs_test.go b/internal/service/ref/refs_test.go
index 476f98285..a026fbd41 100644
--- a/internal/service/ref/refs_test.go
+++ b/internal/service/ref/refs_test.go
@@ -301,6 +301,43 @@ func TestHeadReferenceWithNonExistingHead(t *testing.T) {
 	}
 }
 
+func TestSetDefaultBranchRef(t *testing.T) {
+	testCases := []struct {
+		desc        string
+		ref         string
+		expectedRef string
+	}{
+		{
+			desc:        "update the branch ref",
+			ref:         "refs/heads/feature",
+			expectedRef: "refs/heads/feature",
+		},
+		{
+			desc:        "unknown ref",
+			ref:         "refs/heads/non_existent_ref",
+			expectedRef: "refs/heads/master",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+
+			testRepo, _, cleanupFn := testhelper.NewTestRepo(t)
+			defer cleanupFn()
+
+			err := SetDefaultBranchRef(ctx, testRepo, tc.ref)
+			require.NoError(t, err)
+
+			newRef, err := DefaultBranchName(ctx, testRepo)
+			require.NoError(t, err)
+
+			require.Equal(t, tc.expectedRef, string(newRef))
+		})
+	}
+}
+
 func TestDefaultBranchName(t *testing.T) {
 	// We are going to override these functions during this test. Restore them after we're done
 	defer func() {
diff --git a/internal/service/remote/fetch_internal_remote.go b/internal/service/remote/fetch_internal_remote.go
index 6365e3cec..08863b24e 100644
--- a/internal/service/remote/fetch_internal_remote.go
+++ b/internal/service/remote/fetch_internal_remote.go
@@ -1,6 +1,7 @@
 package remote
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 
@@ -8,6 +9,7 @@ import (
 	"gitlab.com/gitlab-org/gitaly/internal/git"
 	"gitlab.com/gitlab-org/gitaly/internal/gitalyssh"
 	"gitlab.com/gitlab-org/gitaly/internal/helper"
+	"gitlab.com/gitlab-org/gitaly/internal/service/ref"
 	"gitlab.com/gitlab-org/gitaly/proto/go/gitalypb"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
@@ -51,6 +53,22 @@ func (s *server) FetchInternalRemote(ctx context.Context, req *gitalypb.FetchInt
 		return &gitalypb.FetchInternalRemoteResponse{Result: false}, nil
 	}
 
+	remoteDefaultBranch, err := ref.DefaultBranchName(ctx, req.RemoteRepository)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "FetchInternalRemote: remote default branch: %v", err)
+	}
+
+	defaultBranch, err := ref.DefaultBranchName(ctx, req.Repository)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "FetchInternalRemote: default branch: %v", err)
+	}
+
+	if !bytes.Equal(defaultBranch, remoteDefaultBranch) {
+		if err := ref.SetDefaultBranchRef(ctx, req.Repository, string(remoteDefaultBranch)); err != nil {
+			return nil, status.Errorf(codes.Internal, "FetchInternalRemote: set default branch: %v", err)
+		}
+	}
+
 	return &gitalypb.FetchInternalRemoteResponse{Result: true}, nil
 }
 
diff --git a/internal/service/remote/fetch_internal_remote_test.go b/internal/service/remote/fetch_internal_remote_test.go
index 3dc4079ee..a5b42c455 100644
--- a/internal/service/remote/fetch_internal_remote_test.go
+++ b/internal/service/remote/fetch_internal_remote_test.go
@@ -26,6 +26,8 @@ func TestSuccessfulFetchInternalRemote(t *testing.T) {
 	remoteRepo, remoteRepoPath, remoteCleanupFn := testhelper.NewTestRepo(t)
 	defer remoteCleanupFn()
 
+	testhelper.MustRunCommand(t, nil, "git", "-C", remoteRepoPath, "symbolic-ref", "HEAD", "refs/heads/feature")
+
 	repo, repoPath, cleanupFn := testhelper.InitBareRepo(t)
 	defer cleanupFn()
 
@@ -44,9 +46,10 @@ func TestSuccessfulFetchInternalRemote(t *testing.T) {
 	require.NoError(t, err)
 	require.True(t, c.GetResult())
 
-	remoteRefs := testhelper.GetRepositoryRefs(t, remoteRepoPath)
-	refs := testhelper.GetRepositoryRefs(t, repoPath)
-	require.Equal(t, remoteRefs, refs)
+	require.Equal(t,
+		string(testhelper.MustRunCommand(t, nil, "git", "-C", remoteRepoPath, "show-ref", "--head")),
+		string(testhelper.MustRunCommand(t, nil, "git", "-C", repoPath, "show-ref", "--head")),
+	)
 }
 
 func TestFailedFetchInternalRemote(t *testing.T) {