Based on the original message that did + 64 and that this revised to + 5, it might be that a float64 can be serialized to at most 13 ASCII characters (not true

Based on the original message that did + 64 and that this revised to + 5, it might be that a float64 can be serialized to at most 13 ASCII characters (not true in general but might be true of cjson's serializer; I didn't check). The original buffer would only have 8 bytes since that's the width of the f64, so 5 more bytes are needed.