Resolve LFS objects from git common dir

internal/pipeline/build.go

@@ -733,10 +733,14 @@ func chunksFromManifest(assets []assetResource, entries []BuildManifestHAK) ([]h
 
 func collectLFSAssetInfo(p *project.Project) (map[string]lfsAssetInfo, error) {
 	result := make(map[string]lfsAssetInfo)
+	lfsObjectRoot, err := resolveLFSObjectRoot(p.Root)
+	if err != nil {
+		return nil, err
+	}
 	for _, rel := range p.Inventory.AssetFiles {
 		rel = filepath.ToSlash(rel)
 		abs := filepath.Join(p.AssetsDir(), filepath.FromSlash(rel))
-		info, ok, err := parseLFSPointerFile(abs, p.Root)
+		info, ok, err := parseLFSPointerFile(abs, lfsObjectRoot)
 		if err != nil {
 			return nil, err
 		}
@@ -748,7 +752,22 @@ func collectLFSAssetInfo(p *project.Project) (map[string]lfsAssetInfo, error) {
 	return result, nil
 }
 
-func parseLFSPointerFile(path, repoRoot string) (lfsAssetInfo, bool, error) {
+func resolveLFSObjectRoot(repoRoot string) (string, error) {
+	output, err := gitOutput(repoRoot, "rev-parse", "--git-common-dir")
+	if err != nil {
+		return filepath.Join(repoRoot, ".git", "lfs", "objects"), nil
+	}
+	commonDir := strings.TrimSpace(output)
+	if commonDir == "" {
+		return filepath.Join(repoRoot, ".git", "lfs", "objects"), nil
+	}
+	if !filepath.IsAbs(commonDir) {
+		commonDir = filepath.Join(repoRoot, commonDir)
+	}
+	return filepath.Join(filepath.Clean(commonDir), "lfs", "objects"), nil
+}
+
+func parseLFSPointerFile(path, lfsObjectRoot string) (lfsAssetInfo, bool, error) {
 	entry, err := os.Lstat(path)
 	if err != nil {
 		return lfsAssetInfo{}, false, fmt.Errorf("stat %s: %w", path, err)
@@ -784,7 +803,7 @@ func parseLFSPointerFile(path, repoRoot string) (lfsAssetInfo, bool, error) {
 		return lfsAssetInfo{}, false, nil
 	}
 	if len(info.OID) >= 4 {
-		info.ObjectPath = filepath.Join(repoRoot, ".git", "lfs", "objects", info.OID[:2], info.OID[2:4], info.OID)
+		info.ObjectPath = filepath.Join(lfsObjectRoot, info.OID[:2], info.OID[2:4], info.OID)
 	}
 	return info, true, nil
 }

internal/pipeline/pipeline_test.go

@@ -1874,6 +1874,59 @@ func TestPlanHAKChunksPutsNewestAssetsInLastChunk(t *testing.T) {
 	}
 }
 
+func TestCollectLFSAssetInfoUsesGitCommonDirForWorktree(t *testing.T) {
+	if _, err := exec.LookPath("git"); err != nil {
+		t.Skip("git not available")
+	}
+
+	parent := t.TempDir()
+	repoRoot := filepath.Join(parent, "repo")
+	worktreeRoot := filepath.Join(parent, "worktree")
+	mustMkdir(t, repoRoot)
+	runGitTest(t, repoRoot, "init")
+	mustWriteFile(t, filepath.Join(repoRoot, "README.md"), "test\n")
+	runGitTest(t, repoRoot, "add", ".")
+	runGitTest(t, repoRoot, "config", "user.name", "Test User")
+	runGitTest(t, repoRoot, "config", "user.email", "test@example.com")
+	runGitTest(t, repoRoot, "commit", "-m", "initial")
+	runGitTest(t, repoRoot, "worktree", "add", worktreeRoot, "HEAD")
+
+	oid := strings.Repeat("a", 64)
+	assetRel := filepath.Join("core", "foo.mdl")
+	assetPath := filepath.Join(worktreeRoot, "assets", assetRel)
+	mustMkdir(t, filepath.Dir(assetPath))
+	mustWriteFile(t, assetPath, "version https://git-lfs.github.com/spec/v1\n"+"oid sha256:"+oid+"\n"+"size 5\n")
+
+	lfsObjectPath := filepath.Join(repoRoot, ".git", "lfs", "objects", oid[:2], oid[2:4], oid)
+	mustMkdir(t, filepath.Dir(lfsObjectPath))
+	mustWriteFile(t, lfsObjectPath, "model")
+
+	proj := &project.Project{
+		Root: worktreeRoot,
+		Config: project.Config{
+			Paths: project.PathConfig{Source: "src", Assets: "assets", Build: "build"},
+		},
+		Inventory: project.Inventory{
+			AssetFiles: []string{filepath.ToSlash(assetRel)},
+		},
+	}
+
+	infos, err := collectLFSAssetInfo(proj)
+	if err != nil {
+		t.Fatalf("collect lfs asset info: %v", err)
+	}
+	info, ok := infos[filepath.ToSlash(assetRel)]
+	if !ok {
+		t.Fatal("expected LFS asset info")
+	}
+	if got, want := info.ObjectPath, lfsObjectPath; got != want {
+		t.Fatalf("unexpected LFS object path:\ngot  %s\nwant %s", got, want)
+	}
+	if _, err := lfsPathResource(assetPath, info, true); err != nil {
+		t.Fatalf("expected worktree LFS object to resolve: %v", err)
+	}
+}
+
 func runGitCommitTest(t *testing.T, dir, timestamp, message string) {
 	t.Helper()
 	runGitTest(t, dir, "add", ".")