increase varint.WriteTo range

gumble/varint/write.go

@@ -11,14 +11,25 @@ import (
 // and nil.
 func WriteTo(w io.Writer, value int64) (int64, error) {
 	var length int
-	var buff [2]byte
+	var buff [4]byte
 	if value <= 0x7F {
 		buff[0] = byte(value)
 		length = 1
 	} else if value <= 0x3FFF {
 		buff[0] = byte(((value >> 8) & 0x3F) | 0x80)
 		buff[1] = byte(value & 0xFF)
 		length = 2
+	} else if value <= 0x1FFFFF {
+		buff[0] = byte((value >> 16) & 0x1F | 0xC0)
+		buff[1] = byte((value >> 8) & 0xFF)
+		buff[2] = byte(value & 0xFF)
+		length = 3
+	} else if value <= 0xFFFFFFF {
+		buff[0] = byte((value >> 24) & 0xF | 0xE0)
+		buff[1] = byte((value >> 16) & 0xFF)
+		buff[2] = byte((value >> 8) & 0xFF)
+		buff[3] = byte(value & 0xFF)
+		length = 4
 	}
 	if length > 0 {
 		if n, err := w.Write(buff[:length]); err != nil {