Handle more encoding conversion edge cases

1 files changed, 13 insertions, 12 deletions

diff --git a/reader/encoding/encoding.go b/reader/encoding/encoding.go
index 497b2d0..7f4abda 100644
--- a/reader/encoding/encoding.go
+++ b/reader/encoding/encoding.go
@@ -7,6 +7,7 @@ package encoding // import "miniflux.app/reader/encoding"
 import (
 	"bytes"
 	"io"
+	"io/ioutil"
 	"unicode/utf8"
 
 	"golang.org/x/net/html/charset"
@@ -19,20 +20,20 @@ import (
 //
 // Several edge cases could exists:
 //
-// - Feeds with charset specified only in Content-Type header and not in XML document
-// - Feeds with charset specified in both places
-// - Feeds with charset specified only in XML document and not in HTTP header
+// - Feeds with encoding specified only in Content-Type header and not in XML document
+// - Feeds with encoding specified in both places
+// - Feeds with encoding specified only in XML document and not in HTTP header
+// - Feeds with wrong encoding defined and already in UTF-8
 func CharsetReader(label string, input io.Reader) (io.Reader, error) {
-	var buf1, buf2 bytes.Buffer
-	w := io.MultiWriter(&buf1, &buf2)
-	io.Copy(w, input)
-	r := bytes.NewReader(buf2.Bytes())
+	buffer, _ := ioutil.ReadAll(input)
+	r := bytes.NewReader(buffer)
 
-	if !utf8.Valid(buf1.Bytes()) {
-		// Transform document to UTF-8 from the specified XML encoding.
-		return charset.NewReaderLabel(label, r)
+	// The document is already UTF-8, do not do anything (avoid double-encoding).
+	// That means the specified encoding in XML prolog is wrong.
+	if utf8.Valid(buffer) {
+		return r, nil
 	}
 
-	// The document is already UTF-8, do not do anything (avoid double-encoding)
-	return r, nil
+	// Transform document to UTF-8 from the specified encoding in XML prolog.
+	return charset.NewReaderLabel(label, r)
 }