Xml Empty Data Exception

Empty data generate an error because  on line:

https://github.com/skler/serializer/blob/d177ebdd35e7a1c6e525506d3e8926632f353a36/src/JMS/Serializer/XmlDeserializationVisitor.php#L86

libxml_get_last_error() returns false 
Sorry @stof I don't understand, where libxml changes its state? 

Another solution could be to check that serialization/deserialization methods doesn't receive empty data, or allow it and create a valid, but empty, XML. In any case now I guess there is a bug because XmlErrorException class expects one LibXMLError object not a boolean.