Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/common/encoding/decoder.go

@@ -0,0 +1,34 @@
+package encoding
+
+import (
+	"errors"
+
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/unicode"
+)
+
+// NewDecoder returns an x/text Decoder for the specified text encoding.  The
+// Decoder converts a character encoding into utf-8 bytes.  If a BOM is found
+// it will be converted into an utf-8 BOM, you can use
+// github.com/dimchansky/utfbom to strip the BOM.
+//
+// The "none" or "" encoding will pass through bytes unchecked.  Use the utf-8
+// encoding if you want invalid bytes replaced using the unicode
+// replacement character.
+//
+// Detection of utf-16 endianness using the BOM is not currently provided due
+// to the tail input plugins requirement to be able to start at the middle or
+// end of the file.
+func NewDecoder(enc string) (*Decoder, error) {
+	switch enc {
+	case "utf-8":
+		return createDecoder(unicode.UTF8.NewDecoder()), nil
+	case "utf-16le":
+		return createDecoder(unicode.UTF16(unicode.LittleEndian, unicode.IgnoreBOM).NewDecoder()), nil
+	case "utf-16be":
+		return createDecoder(unicode.UTF16(unicode.BigEndian, unicode.IgnoreBOM).NewDecoder()), nil
+	case "none", "":
+		return createDecoder(encoding.Nop.NewDecoder()), nil
+	}
+	return nil, errors.New("unknown character encoding")
+}