Add error return value to metainfo.MetaInfo.UnmarshalInfo

Too many problems caused by bad info bytes in downstream projects.

metainfo/magnet_test.go

@@ -74,7 +74,9 @@ func TestMagnetize(t *testing.T) {
 	mi, err := LoadFromFile("../testdata/bootstrap.dat.torrent")
 	require.NoError(t, err)
 
-	m := mi.Magnet(mi.UnmarshalInfo().Name, mi.HashInfoBytes())
+	info, err := mi.UnmarshalInfo()
+	require.NoError(t, err)
+	m := mi.Magnet(info.Name, mi.HashInfoBytes())
 
 	assert.EqualValues(t, "bootstrap.dat", m.DisplayName)
 

metainfo/metainfo.go

@@ -1,7 +1,6 @@
 package metainfo
 
 import (
-	"fmt"
 	"io"
 	"os"
 	"time"
@@ -49,11 +48,8 @@ func LoadFromFile(filename string) (*MetaInfo, error) {
 	return Load(f)
 }
 
-func (mi MetaInfo) UnmarshalInfo() (info Info) {
-	err := bencode.Unmarshal(mi.InfoBytes, &info)
-	if err != nil {
-		panic(fmt.Sprintf("bad info bytes: %s", err))
-	}
+func (mi MetaInfo) UnmarshalInfo() (info Info, err error) {
+	err = bencode.Unmarshal(mi.InfoBytes, &info)
 	return
 }
 

metainfo/metainfo_test.go

@@ -18,8 +18,9 @@ import (
 func testFile(t *testing.T, filename string) {
 	mi, err := LoadFromFile(filename)
 	require.NoError(t, err)
+	info, err := mi.UnmarshalInfo()
+	require.NoError(t, err)
 
-	info := mi.UnmarshalInfo()
 	if len(info.Files) == 1 {
 		t.Logf("Single file: %s (length: %d)\n", info.Name, info.Files[0].Length)
 	} else {

spec.go

@@ -34,7 +34,7 @@ func TorrentSpecFromMagnetURI(uri string) (spec *TorrentSpec, err error) {
 }
 
 func TorrentSpecFromMetaInfo(mi *metainfo.MetaInfo) (spec *TorrentSpec) {
-	info := mi.UnmarshalInfo()
+	info, _ := mi.UnmarshalInfo()
 	spec = &TorrentSpec{
 		Trackers:    mi.AnnounceList,
 		InfoBytes:   mi.InfoBytes,