Merge pull request #13 from gerow/utf16_comm_write_fix

Fixed the way id3-go writes back comm tags when using utf16

encodedbytes/writer.go

@@ -51,7 +51,14 @@ func (w *Writer) WriteString(s string, encoding byte) (err error) {
 func (w *Writer) WriteNullTermString(s string, encoding byte) (err error) {
 	err = w.WriteString(s, encoding)
 	if err == nil {
-		err = w.WriteByte(0)
+		nullLength := EncodingMap[encoding].NullLength
+
+		for i := 0; i < nullLength; i++ {
+			err = w.WriteByte(0)
+			if err != nil {
+				return
+			}
+		}
 	}
 	return
 }

id3_test.go

@@ -6,6 +6,7 @@ package id3
 import (
 	"bytes"
 	v2 "github.com/mikkyang/id3-go/v2"
+	"io"
 	"io/ioutil"
 	"os"
 	"testing"
@@ -37,6 +38,24 @@ func TestOpen(t *testing.T) {
 	if s := tag.Album(); s != "Chief Life" {
 		t.Errorf("Open: incorrect album, %v", s)
 	}
+
+	parsedFrame := file.Frame("COMM")
+	resultFrame, ok := parsedFrame.(*v2.UnsynchTextFrame)
+	if !ok {
+		t.Error("Couldn't cast frame")
+	}
+
+	expected := "✓"
+	actual := resultFrame.Description()
+
+	if expected != actual {
+		t.Errorf("Expected %q, got %q", expected, actual)
+	}
+
+	actual = resultFrame.Text()
+	if expected != actual {
+		t.Errorf("Expected %q, got %q", expected, actual)
+	}
 }
 
 func TestClose(t *testing.T) {
@@ -152,3 +171,24 @@ func TestUnsynchTextFrame_RoundTrip(t *testing.T) {
 		}
 	}
 }
+
+func TestUTF16CommPanic(t *testing.T) {
+	osFile, err := os.Open(testFile)
+	if err != nil {
+		t.Error(err)
+	}
+	tempfile, err := ioutil.TempFile("", "utf16_comm")
+	if err != nil {
+		t.Error(err)
+	}
+	io.Copy(tempfile, osFile)
+	osFile.Close()
+	tempfile.Close()
+	for i := 0; i < 2; i++ {
+		file, err := Open(tempfile.Name())
+		if err != nil {
+			t.Error(err)
+		}
+		file.Close()
+	}
+}