Official website try! tab is not right for int64

[ebwood]

In official website https://msgpack.org/, choose Try! tab and input value like below:

The value of age is -2^63 + 1
The result is wrong in the last byte, it should be 01 instead of 00.

[DrewMcArthur]

pretty sure i'm seeing this too; both numbers 1111111111111111168 and 1111111111111111111 return the same packed value: cf 0f 6b 75 ab 2b c4 72 00 (which i think decodes to the former int, according to the spec).

[ObjectBoxPC]

This is because JavaScript numbers are IEEE 754 double-precision floating point numbers, which can't precisely represent integers that large. So when the JSON input is parsed, the resulting number may be off, which is then carried over to the MsgPack output.