fix(archive): prefer utf-8 for non-EFS zip names (#2557)

internal/archive/zip/utils.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"io/fs"
 	"strings"
+	"unicode/utf8"
 
 	"github.com/KirCute/zip"
 	"github.com/OpenListTeam/OpenList/v4/internal/archive/tool"
@@ -101,6 +102,9 @@ func decodeName(name string, efs bool) string {
 	if efs {
 		return name
 	}
+	if utf8.ValidString(name) {
+		return name
+	}
 	enc, err := ianaindex.IANA.Encoding(setting.GetStr(conf.NonEFSZipEncoding))
 	if err != nil {
 		return name

internal/archive/zip/utils_test.go

@@ -0,0 +1,41 @@
+package zip
+
+import (
+	"testing"
+
+	"github.com/OpenListTeam/OpenList/v4/internal/conf"
+	"github.com/OpenListTeam/OpenList/v4/internal/model"
+	"github.com/OpenListTeam/OpenList/v4/internal/op"
+	"github.com/OpenListTeam/OpenList/v4/internal/setting"
+	"github.com/stretchr/testify/require"
+)
+
+func setNonEFSZipEncoding(value string) {
+	op.Cache.SetSetting(conf.NonEFSZipEncoding, &model.SettingItem{
+		Key:   conf.NonEFSZipEncoding,
+		Value: value,
+	})
+}
+
+func TestDecodeNamePrefersValidUTF8WhenEFSDisabled(t *testing.T) {
+	setNonEFSZipEncoding("IBM437")
+
+	name := "中文.txt"
+	require.Equal(t, name, decodeName(name, false))
+	// Ensure the setting still exists to verify we did not bypass config due to missing setup.
+	require.Equal(t, "IBM437", setting.GetStr(conf.NonEFSZipEncoding))
+}
+
+func TestDecodeNameFallsBackToConfiguredEncoding(t *testing.T) {
+	setNonEFSZipEncoding("GB18030")
+
+	name := string([]byte{0xd6, 0xd0, 0xce, 0xc4, '.', 't', 'x', 't'})
+	require.Equal(t, "中文.txt", decodeName(name, false))
+}
+
+func TestDecodeNameRespectsEFSFlag(t *testing.T) {
+	setNonEFSZipEncoding("GB18030")
+
+	name := "utf8-name.txt"
+	require.Equal(t, name, decodeName(name, true))
+}