fix: fall back to sha1 for an unusable DEFAULT_OBJECT_FORMAT

API creation and push-to-create now use DEFAULT_OBJECT_FORMAT, so an
invalid value or sha256 on git older than 2.42 would break them or store a
format that differs from the repo on disk. Keep the cargo index on sha1
since cargo clients can't fetch sha256 repos, and only probe the on-disk
format during LFS garbage collection when an object needs checking.

Assisted-by: Claude Code:claude-opus-5-5

Author: silverwind

modules/git/archive_test.go

@@ -17,18 +17,17 @@ import (
 func TestCreateBundle(t *testing.T) {
 	setting.AppDataPath = t.TempDir()
 
-	for _, tc := range []struct{ repo, commit, version string }{
-		{"repo1_bare", "ce064814f4a0d337b333e646ece456cd39fab612", "# v2 git bundle"},
-		{"repo1_bare_sha256", "9433b2a62b964c17a4485ae180f45f595d3e69d31b786087775e28c6b6399df0", "# v3 git bundle"},
-	} {
-		buf := &bytes.Buffer{}
-		require.NoError(t, CreateBundle(t.Context(), mockRepository(tc.repo), tc.commit, buf))
-
-		header, _, ok := strings.Cut(buf.String(), "\n\n")
-		require.True(t, ok)
-		assert.Equal(t, tc.version, strings.Split(header, "\n")[0])
-		// without a refs/heads/* ref and a HEAD, a clone of the bundle has no branch and no checkout
-		assert.Contains(t, header, tc.commit+" refs/heads/bundle")
-		assert.Contains(t, header, tc.commit+" HEAD")
-	}
+	buf := &bytes.Buffer{}
+	require.NoError(t, CreateBundle(t.Context(), mockRepository("repo1_bare"), "ce064814f4a0d337b333e646ece456cd39fab612", buf))
+
+	header, _, ok := strings.Cut(buf.String(), "\n\n")
+	require.True(t, ok)
+	assert.Equal(t, "# v2 git bundle", strings.Split(header, "\n")[0])
+	// without a refs/heads/* ref and a HEAD, a clone of the bundle has no branch and no checkout
+	assert.Contains(t, header, "ce064814f4a0d337b333e646ece456cd39fab612 refs/heads/bundle")
+	assert.Contains(t, header, "ce064814f4a0d337b333e646ece456cd39fab612 HEAD")
+
+	buf.Reset()
+	require.NoError(t, CreateBundle(t.Context(), mockRepository("repo1_bare_sha256"), "9433b2a62b964c17a4485ae180f45f595d3e69d31b786087775e28c6b6399df0", buf))
+	assert.True(t, strings.HasPrefix(buf.String(), "# v3 git bundle\n@object-format=sha256\n"))
 }

modules/structs/hook.go

@@ -108,7 +108,7 @@ type PayloadUser struct {
 
 // PayloadCommit represents a commit
 type PayloadCommit struct {
-	// hash of the commit
+	// sha1 hash of the commit
 	ID string `json:"id"`
 	// The commit message
 	Message string `json:"message"`

routers/api/v1/repo/hash_algorithm.go

@@ -1311,3 +1311,29 @@ func ListRepoActivityFeeds(ctx *context.APIContext) {
 
 	ctx.JSON(http.StatusOK, convert.ToActivities(ctx, feeds, ctx.Doer))
 }
+
+func GetHashAlgorithm(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/hash-algorithm repository repoGetHashAlgorithm
+	// ---
+	// summary: Get the hash algorithm used to store repository objects
+	// produces:
+	//   - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/RepoHashAlgorithm"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	ctx.JSON(http.StatusOK, api.RepoHashAlgorithm{HashAlgorithm: api.ObjectFormatName(ctx.Repo.Repository.ObjectFormatName)})
+}

routers/api/v1/repo/repo.go

@@ -122,6 +122,10 @@ func InitWebInstalled(ctx context.Context) {
 	translation.InitLocales(ctx)
 
 	setting.LoadSettings()
+	if !git.IsValidObjectFormat(setting.Repository.DefaultObjectFormat) {
+		log.Warn("[repository] DEFAULT_OBJECT_FORMAT %q is not supported, using sha1", setting.Repository.DefaultObjectFormat)
+		setting.Repository.DefaultObjectFormat = git.Sha1ObjectFormat.Name()
+	}
 	mustInit(storage.Init)
 
 	mailer.NewContext(ctx)

routers/init.go

@@ -212,7 +212,8 @@ func getOrCreateIndexRepository(ctx context.Context, doer, owner *user_model.Use
 	if err != nil {
 		if errors.Is(err, util.ErrNotExist) {
 			repo, err = repo_service.CreateRepositoryDirectly(ctx, doer, owner, repo_service.CreateRepoOptions{
-				Name: IndexRepositoryName,
+				Name:             IndexRepositoryName,
+				ObjectFormatName: git.Sha1ObjectFormat.Name(), // cargo clients can't fetch sha256 repos
 			}, true)
 			if err != nil {
 				return nil, fmt.Errorf("CreateRepository: %w", err)

services/packages/cargo/index.go

@@ -82,16 +82,16 @@ func GarbageCollectLFSMetaObjectsForRepo(ctx context.Context, repo *repo_model.R
 
 	store := lfs.NewContentStore()
 	errStop := errors.New("STOPERR")
-	objectFormat, err := gitRepo.GetObjectFormat(ctx) // on-disk format, the stored one can disagree with it
-	if err != nil {
-		return err
-	}
 
 	err = git_model.IterateLFSMetaObjectsForRepo(ctx, repo.ID, func(ctx context.Context, metaObject *git_model.LFSMetaObject, count int64) error {
 		if opts.NumberToCheckPerRepo > 0 && total > opts.NumberToCheckPerRepo {
 			return errStop
 		}
 		total++
+		objectFormat, err := gitRepo.GetObjectFormat(ctx) // on-disk format, the stored one can disagree with it
+		if err != nil {
+			return err
+		}
 		pointerSha := git.ComputeBlobHash(objectFormat, []byte(metaObject.Pointer.StringContent()))
 
 		if gitRepo.IsObjectExist(ctx, pointerSha.String()) {

services/repository/lfs.go

@@ -24,11 +24,12 @@ import (
 )
 
 type APITestContext struct {
-	Reponame         string
-	Session          *TestSession
-	Token            string
-	Username         string
-	ExpectedCode     int
+	Reponame     string
+	Session      *TestSession
+	Token        string
+	Username     string
+	ExpectedCode int
+
 	ObjectFormatName api.ObjectFormatName
 }