fix err handling

Author: wxiaoguang

modules/git/gitcmd/command.go

@@ -426,9 +426,9 @@ type RunStdError interface {
 }
 
 type runStdError struct {
-	err    error
-	stderr string
-	errMsg string
+	err    error  // usually the low-level error like exec.ExitError
+	stderr string // git command's stderr output
+	errMsg string // the cached error message for Error() method
 }
 
 func (r *runStdError) Error() string {
@@ -448,6 +448,22 @@ func (r *runStdError) Stderr() string {
 	return r.stderr
 }
 
+func ErrorAsStderr(err error) (string, bool) {
+	var runErr RunStdError
+	if errors.As(err, &runErr) {
+		return runErr.Stderr(), true
+	}
+	return "", false
+}
+
+func StderrHasPrefix(err error, prefix string) bool {
+	stderr, ok := ErrorAsStderr(err)
+	if !ok {
+		return false
+	}
+	return strings.HasPrefix(stderr, prefix)
+}
+
 func IsErrorExitCode(err error, code int) bool {
 	var exitError *exec.ExitError
 	if errors.As(err, &exitError) {

modules/git/gitcmd/utils.go

@@ -3,12 +3,16 @@
 
 package gitcmd
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+)
 
-// ConcatenateError concatenats an error with stderr string
+// ConcatenateError concatenates an error with stderr string
+// FIXME: use RunStdError instead
 func ConcatenateError(err error, stderr string) error {
 	if len(stderr) == 0 {
 		return err
 	}
-	return fmt.Errorf("%w - %s", err, stderr)
+	return errors.Join(fmt.Errorf("%w - %s", err, stderr), &runStdError{err: err, stderr: stderr})
 }

services/repository/archiver/archiver.go

@@ -329,9 +329,8 @@ func ServeRepoArchive(ctx *gitea_context.Base, archiveReq *ArchiveRequest) error
 		// the header must be set before starting streaming even an error would occur,
 		// because errors may happen in git command and such cases aren't in our control.
 		httplib.ServeSetHeaders(ctx.Resp, &httplib.ServeHeaderOptions{Filename: downloadName})
-		var gitErr gitcmd.RunStdError
 		if err := archiveReq.Stream(ctx, ctx.Resp); err != nil && !ctx.Written() {
-			if errors.As(err, &gitErr); strings.HasPrefix(gitErr.Stderr(), "fatal: pathspec") {
+			if gitcmd.StderrHasPrefix(err, "fatal: pathspec") {
 				return util.NewInvalidArgumentErrorf("path doesn't exist or is invalid")
 			}
 			return fmt.Errorf("archive repo %s: failed to stream: %w", archiveReq.Repo.FullName(), err)

services/repository/archiver/archiver_test.go

@@ -8,11 +8,13 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/contexttest"
 
 	_ "code.gitea.io/gitea/models/actions"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestMain(m *testing.M) {
@@ -124,4 +126,13 @@ func TestArchive_Basic(t *testing.T) {
 	// Ideally, the extension would match what we originally requested.
 	assert.NotEqual(t, zipReq.GetArchiveName(), tgzReq.GetArchiveName())
 	assert.NotEqual(t, zipReq.GetArchiveName(), secondReq.GetArchiveName())
+
+	t.Run("BadPath", func(t *testing.T) {
+		badRequest, err := NewRequest(ctx.Repo.Repository, ctx.Repo.GitRepo, firstCommit+".tar.gz", []string{"not-a-path"})
+		require.NoError(t, err)
+		err = ServeRepoArchive(ctx.Base, badRequest)
+		require.Error(t, err)
+		assert.ErrorIs(t, err, util.ErrInvalidArgument)
+		assert.ErrorContains(t, err, "path doesn't exist or is invalid")
+	})
 }