MsgPack: support full UInt64 range when decoding

[wdoo01]

Hi, thanks for DDO — it works very well overall.

I noticed an issue when decoding MsgPack uint64 values at the upper end of the range. For example, decoding UInt64.MaxValue raises an exception:

is too large of an unsigned 64-bit integer to fit in a signed 64-bit integer type.

I traced this to DataObjects2MsgPack.pas, where large uint64 values are explicitly rejected:

$cf: begin  // uInt 64
  fStream.Read(lUInt64, 8);
  lUInt64 := SwapBytes(lUInt64);
  if lUInt64 <= $7FFFFFFFFFFFFFFF then
    aDataObj.AsInt64 := lUInt64
  else
    raise Exception.Create(IntToHex(lUInt64)+' is too large of an unsigned 64-bit integer to fit in a signed 64-bit integer type.');
end;

From the codebase, it seems TDataObj already has a SetAsUInt64 method. Because of that, I wanted to ask:

• Is there a design reason why MsgPack decoding does not support the full UInt64 range?
• Would it be possible to decode $cf values larger than Int64.MaxValue via AsUInt64 instead of raising an exception?

It would be great if DDO could support the full MsgPack uint64 range.

If helpful, I can also put together a minimal repro case.