[python-win32] Callback RemQueryInterface gives E_NOINTERFACE

[Jim Bell]

I've been though all the demos and scoured the web, and am stumped. But 
I think I'm close. I have a 3rd-party .dll/.tlb. I run makepy.py and it 
works fine.  I need to pass a callback interface, which they define, 
into one of their functions. Here's where I'm stumped.

gencache.EnsureModule('{F8EF...}', 0, 1, 0) # via makepy -i -v

# IID defined in the 3rd-party library...
cbIID = IID('{188....}') # valid IID of ITheirCallBack

# My callback class...
class MyCallBack:
     _public_methods_ = [ 'GotMsg' ]
     _com_interfaces_ = [ cbIID ] # as defined above

     def GotMsg(self, msg):
         print 'GotMsg: %s' % str(msg) # Hey!

# This doesn't work: 'Library not registered'
win32com.universal.RegisterInterfaces('{188...}', 0, 1, 0, [ 
'ITheirCallBack'])

# Instantiate my callback...
cbRaw = MyCallBack() # Works fine.

# If I pass cbIID as param 2 here, I get 'No such interface supported'
cbCom = win32com.server.util.wrap(cbRaw)

cliObj = win32com.client.Dispatch('theirlib.Server.1') # Fine!

# Crux: we make the call,
# but Wireshark shows RemQueryInterface back to us,
# for ITheirCallBack/cbIID,
# and our machine returns E_NOINTERFACE
cliObj.InitServer(cbCom) # Doesn't crash, but fails.