Regression in msgpack-python 1.0.0 wraps around timestamps after 2038

[progval]

Hi,

I just found this data corruption after upgrading msgpack from 1.0.0 to 1.0.1:

$ pip3 install --user msgpack==1.0.0
[...]
$ python3 -c "import msgpack, datetime; print(msgpack.unpackb(msgpack.packb(datetime.datetime(2100, 1, 1, 1, 1, tzinfo=datetime.timezone.utc), datetime=True), timestamp=3))"
2100-01-01 01:01:00+00:00
$ pip3 install --user msgpack==1.0.1
[...]
$ python3 -c "import msgpack, datetime; print(msgpack.unpackb(msgpack.packb(datetime.datetime(2100, 1, 1, 1, 1, tzinfo=datetime.timezone.utc), datetime=True), timestamp=3))"
1963-11-25 18:32:44+00:00

[methane]

On my mac:

$ python3 -m venv venv
$ source venv/bin/activate

$ pip install msgpack==1.0.0
...
Successfully installed msgpack-1.0.0

$ python -c "import msgpack, datetime; print(msgpack.unpackb(msgpack.packb(datetime.datetime(2100, 1, 1, 1, 1, tzinfo=datetime.timezone.utc), datetime=True), timestamp=3))"
2100-01-01 01:01:00+00:00

$ pip install msgpack==1.0.1
...
Successfully installed msgpack-1.0.1

$ python -c "import msgpack, datetime; print(msgpack.unpackb(msgpack.packb(datetime.datetime(2100, 1, 1, 1, 1, tzinfo=datetime.timezone.utc), datetime=True), timestamp=3))"
2100-01-01 01:01:00+00:00

What is your enviornment? Do you use speedup module?

[progval]

I'm on Debian 10, python 3.7.3. msgpack was installed from this wheel: https://files.pythonhosted.org/packages/8e/e8/a4b64266a1fb99190a3a03c999395108ef2fde5d912343b2a6cf435d59af/msgpack-1.0.1-cp37-cp37m-manylinux2010_x86_64.whl

I don't know about the speedup module, but I can see this:

>>> msgpack._cmsgpack
<module 'msgpack._cmsgpack' from '/home/tmp/venv/lib/python3.7/site-packages/msgpack/_cmsgpack.cpython-37m-x86_64-linux-gnu.so'>

[jfolz]

Can confirm the issue with Python 3.6 through 3.9 in the manylinux 2014 docker container:

$ sudo docker run --rm -it quay.io/pypa/manylinux2014_x86_64
[root@56d0702a09b2 /]# /opt/python/cp37-cp37m/bin/pip install msgpack==1.0.0
...
Successfully installed msgpack-1.0.0
[root@56d0702a09b2 /]# /opt/python/cp37-cp37m/bin/python -c "import msgpack, datetime; print(msgpack.unpackb(msgpack.packb(datetime.datetime(2100, 1, 1, 1, 1, tzinfo=datetime.timezone.utc), datetime=True), timestamp=3))"
2100-01-01 01:01:00+00:00
[root@56d0702a09b2 /]# /opt/python/cp37-cp37m/bin/pip install msgpack==1.0.1
...
Successfully installed msgpack-1.0.1
[root@56d0702a09b2 /]# /opt/python/cp37-cp37m/bin/python -c "import msgpack, datetime; print(msgpack.unpackb(msgpack.packb(datetime.datetime(2100, 1, 1, 1, 1, tzinfo=datetime.timezone.utc), datetime=True), timestamp=3))"
1963-11-25 18:32:44+00:00
[root@56d0702a09b2 /]#

So it seems the linux build specifically casts to int32 somewhere.

[methane]

https://github.com/msgpack/msgpack-python/pull/436/files#diff-167e9083fc109195a2c1c50f75abecb64b50c3b085af5292ceb76a3cd85f97d3R352