forbids non-int/string map keys (previously they were silently cast to int/string which could result in a warning Illegal offset type)
fixes checking the buffer size required to unpack Ext (previously the Ext "type" byte wasn't taken into account which could result in a notice Uninitialized string offset for extensions with zero-length data)
This PR
Illegal offset type)Uninitialized string offsetfor extensions with zero-length data)