plumbing: object, check legitimacy in (*Tree).Encode, export TreeSorter

niukuo · niukuo · commit a56fb9cd9a39 · 2023-12-13T15:18:26.000+08:00
diff --git a/plumbing/object/tree.go b/plumbing/object/tree.go
@@ -7,6 +7,7 @@ import (
 	"io"
 	"path"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"github.com/go-git/go-git/v5/plumbing"
@@ -270,6 +271,28 @@ func (t *Tree) Decode(o plumbing.EncodedObject) (err error) {
 	return nil
 }
 
+type EntrySorter []TreeEntry
+
+func (s EntrySorter) Len() int {
+	return len(s)
+}
+
+func (s EntrySorter) Less(i, j int) bool {
+	name1 := s[i].Name
+	name2 := s[j].Name
+	if s[i].Mode == filemode.Dir {
+		name1 += "/"
+	}
+	if s[j].Mode == filemode.Dir {
+		name2 += "/"
+	}
+	return name1 < name2
+}
+
+func (s EntrySorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
 // Encode transforms a Tree into a plumbing.EncodedObject.
 func (t *Tree) Encode(o plumbing.EncodedObject) (err error) {
 	o.SetType(plumbing.TreeObject)
@@ -279,7 +302,15 @@ func (t *Tree) Encode(o plumbing.EncodedObject) (err error) {
 	}
 
 	defer ioutil.CheckClose(w, &err)
+
+	if !sort.IsSorted(EntrySorter(t.Entries)) {
+		return errors.New("entries in tree is not sorted")
+	}
+
 	for _, entry := range t.Entries {
+		if strings.IndexByte(entry.Name, 0) != -1 {
+			return fmt.Errorf("malformed filename '%s'", entry.Name)
+		}
 		if _, err = fmt.Fprintf(w, "%o %s", entry.Mode, entry.Name); err != nil {
 			return err
 		}
diff --git a/plumbing/object/tree_test.go b/plumbing/object/tree_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"io"
+	"sort"
 	"testing"
 
 	fixtures "github.com/go-git/go-git-fixtures/v4"
@@ -231,6 +232,7 @@ func (s *TreeSuite) TestTreeDecodeEncodeIdempotent(c *C) {
 		},
 	}
 	for _, tree := range trees {
+		sort.Sort(EntrySorter(tree.Entries))
 		obj := &plumbing.MemoryObject{}
 		err := tree.Encode(obj)
 		c.Assert(err, IsNil)
