From c736731ac9cbbc002d074de200f417decccc3dca Mon Sep 17 00:00:00 2001
From: Paulo Gomes <pjbgf@linux.com>
Date: Sat, 13 Jul 2024 14:24:30 +0100
Subject: utils: merkletrie, Align error message with upstream

Signed-off-by: Paulo Gomes <pjbgf@linux.com>
---
 utils/merkletrie/change.go      |  9 +++++++++
 utils/merkletrie/change_test.go | 11 +++++++++++
 2 files changed, 20 insertions(+)

diff --git a/utils/merkletrie/change.go b/utils/merkletrie/change.go
index cc6dc89..450feb4 100644
--- a/utils/merkletrie/change.go
+++ b/utils/merkletrie/change.go
@@ -1,12 +1,17 @@
 package merkletrie
 
 import (
+	"errors"
 	"fmt"
 	"io"
 
 	"github.com/go-git/go-git/v5/utils/merkletrie/noder"
 )
 
+var (
+	ErrEmptyFileName = errors.New("empty filename in tree entry")
+)
+
 // Action values represent the kind of things a Change can represent:
 // insertion, deletions or modifications of files.
 type Action int
@@ -121,6 +126,10 @@ func (l *Changes) AddRecursiveDelete(root noder.Path) error {
 type noderToChangeFn func(noder.Path) Change // NewInsert or NewDelete
 
 func (l *Changes) addRecursive(root noder.Path, ctor noderToChangeFn) error {
+	if root.String() == "" {
+		return ErrEmptyFileName
+	}
+
 	if !root.IsDir() {
 		l.Add(ctor(root))
 		return nil
diff --git a/utils/merkletrie/change_test.go b/utils/merkletrie/change_test.go
index f73eb86..cd28bfe 100644
--- a/utils/merkletrie/change_test.go
+++ b/utils/merkletrie/change_test.go
@@ -28,6 +28,17 @@ func (s *ChangeSuite) TestUnsupportedAction(c *C) {
 	c.Assert(a.String, PanicMatches, "unsupported action.*")
 }
 
+func (s ChangeSuite) TestEmptyChanges(c *C) {
+	ret := merkletrie.NewChanges()
+	p := noder.Path{}
+
+	err := ret.AddRecursiveInsert(p)
+	c.Assert(err, Equals, merkletrie.ErrEmptyFileName)
+
+	err = ret.AddRecursiveDelete(p)
+	c.Assert(err, Equals, merkletrie.ErrEmptyFileName)
+}
+
 func (s ChangeSuite) TestNewInsert(c *C) {
 	tree, err := fsnoder.New("(a(b(z<>)))")
 	c.Assert(err, IsNil)
-- 
cgit