fix(run): keep the permission bits of extracted artifact files

Signed-off-by: bircni <bircni@icloud.com>

internal/app/artifacts.go

@@ -259,7 +259,8 @@ func extractZip(ctx context.Context, body io.Reader, dir string, clobber, skipEx
 	return nil
 }
 
-// extractFile writes one archive entry to path with the permissions the umask allows.
+// extractFile writes one archive entry to path with its permission bits, such as an executable's,
+// as far as the umask allows; special bits such as setuid are dropped.
 func extractFile(entry *zip.File, path string, clobber, skipExisting bool) error {
 	if err := os.MkdirAll(filepath.Dir(path), 0o777); err != nil {
 		return err
@@ -268,7 +269,7 @@ func extractFile(entry *zip.File, path string, clobber, skipExisting bool) error
 	if clobber {
 		flags = os.O_WRONLY | os.O_CREATE | os.O_TRUNC
 	}
-	file, err := os.OpenFile(path, flags, 0o666)
+	file, err := os.OpenFile(path, flags, cmp.Or(entry.Mode().Perm(), 0o666))
 	if errors.Is(err, os.ErrExist) && skipExisting {
 		return nil
 	}

internal/app/artifacts_test.go

@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 
 	"gitea.dev/tea/internal/clierr"
@@ -127,6 +128,31 @@ func TestRunDownloadExtractsArtifactsByName(t *testing.T) {
 	})
 }
 
+func TestExtractZipKeepsPermissionBits(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("Windows has no permission bits")
+	}
+	var archive bytes.Buffer
+	writer := zip.NewWriter(&archive)
+	for name, mode := range map[string]os.FileMode{"bin/tool": 0o755, "setuid": 0o755 | os.ModeSetuid, "data": 0o644} {
+		header := &zip.FileHeader{Name: name}
+		header.SetMode(mode)
+		file, err := writer.CreateHeader(header)
+		require.NoError(t, err)
+		_, err = file.Write([]byte(name))
+		require.NoError(t, err)
+	}
+	require.NoError(t, writer.Close())
+	dir := t.TempDir()
+	require.NoError(t, extractZip(context.Background(), &archive, dir, false, false))
+	for name, executable := range map[string]bool{"bin/tool": true, "setuid": true, "data": false} {
+		info, err := os.Stat(filepath.Join(dir, name))
+		require.NoError(t, err)
+		require.Equal(t, executable, info.Mode().Perm()&0o100 != 0, name)
+		require.Zero(t, info.Mode()&os.ModeSetuid, name)
+	}
+}
+
 // filepathReplace puts dir in place of {dir} in text.
 func filepathReplace(text, dir string) string {
 	return string(bytes.ReplaceAll([]byte(text), []byte("{dir}"), []byte(dir)))