varkind and invoke_type

[GitBadSanta]

Regarding this commit

Previous implementation was :

def _GetDescInvokeType(entry, default_invoke_type):
    if not entry or not entry.desc: return default_invoke_type
    return entry.desc[4]   # apparently varkind

So this was always returning varkind when entry.desc was defined. The function name is consistent : we try to retrieve invoke_type from desc and return default_invoke_type otherwise.

Regarding new implementation :

def _GetDescInvokeType(entry, invoke_type):
    # determine the wFlags argument passed as input to IDispatch::Invoke
    if not entry or not entry.desc: return invoke_type
    varkind = entry.desc[4] # from VARDESC struct returned by ITypeComp::Bind
    if varkind == pythoncom.VAR_DISPATCH and invoke_type == pythoncom.INVOKE_PROPERTYGET:
        return pythoncom.INVOKE_FUNC | invoke_type # DISPATCH_METHOD & DISPATCH_PROPERTYGET can be combined in IDispatch::Invoke
    else:
        return invoke_type

The logic is totally different, we check varkind to possibly amend invoke_type, but we never return varkind.

In the related issue of this pull request, we found out that when setting AdminQueueInfo member of an MSMQ.MSMQMessage , we call _GetDescInvokeType with an entry verifying entry.desc[4] = 8 and an invoke_type = INVOKE_PROPERTYPUT.
We should get a INVOKE_PROPERTYPUTREF (8), corresponding to entry.desc[4] but new function returns INVOKE_PROPERTYPUT and makes invoke crash.

The pull request is proposing a mix between two implementations, but I'm still really confused, especially with entry.desc[4] which apparently should correspond to varkind. Looking to documentation
varkind values can only be 0,1,2,3.

So what is really entry.desc[4] ?