mapi - AllocMVBuffer (mapiutil.cpp) should set an error after PySequence_Check

[nczeczulin]

SystemError('<built-in function HrSetOneProp> returned NULL without setting an error',)
SystemError('<built-in method SetProps of PyIMessage object at 0x03830D8C> returned NULL without setting an error',)

import pythoncom
from win32com import storagecon
from win32com.mapi import mapi
from win32com.mapi import mapitags

mapi.MAPIInitialize((mapi.MAPI_INIT_VERSION, mapi.MAPI_MULTITHREAD_NOTIFICATIONS))
try:
    lockbytes = pythoncom.CreateILockBytesOnHGlobal(None, True)
    mode = storagecon.STGM_CREATE | storagecon.STGM_READWRITE | storagecon.STGM_SHARE_EXCLUSIVE
    storage = pythoncom.StgCreateDocfileOnILockBytes(lockbytes, mode, 0)
    msg = mapi.OpenIMsgOnIStg(0, None, storage, None, 0, mapi.MAPI_UNICODE)
    proptag = mapitags.PROP_TAG(
        mapitags.PT_MV_I4,
        mapitags.PROP_ID(msg.GetIDsFromNames(((mapi.PS_PUBLIC_STRINGS, 'Test123'),), mapi.MAPI_CREATE)[0])
    )
    try:
        mapi.HrSetOneProp(msg, (proptag, None))
    except Exception as e:
        print(repr(e))
    try:
        msg.SetProps(((proptag, None),))
    except Exception as e:
        print(repr(e))
finally:
    msg = None
    storage = None
    lockbytes = None
    mapi.MAPIUninitialize()