SystemError: NULL result without error in call_object

[Gaetan Corneau]

Hello,

I'm trying to implement a collection and an enumerator in a COM object using
Delphi 5. The following script works:

import com # Just a shortcut

try:
    o = com.Dispatch("TestDLLDriver.TestLib")
    

    o.LoadTestDLL("d:/Compiled/MyDll.dll", "d:/out.txt") # This loads a
"plugin" DLL containing test functions
    print "DLL Name:", o.DLLName
    print "Test Lib Name:", o.Name
    print "Test Lib Description:", o.Description
    print "Output File Name:", o.OutputFileName
    
    print "Number of Test Cases:", o.TestCases.Count
    
    #****** HERE *******
    for i in range(0, o.TestCases.Count):
        tc = o.TestCases.Item(i)
        print "Test Case Name:", tc.Name
        print "Running Test Case:", tc.Run()

    o.UnloadTestDLL()
except Exception, x:
    print "\n\nException:", x


This one doesn't:
import com

try:
    o = com.Dispatch("TestDLLDriver.TestLib")
    

    o.LoadTestDLL("d:/Compiled/MyDll.dll", "d:/out.txt")
    print "DLL Name:", o.DLLName
    print "Test Lib Name:", o.Name
    print "Test Lib Description:", o.Description
    print "Output File Name:", o.OutputFileName
    
    print "Number of Test Cases:", o.TestCases.Count
    
    # **** HERE ****
    for tc in o.TestCases:
        print "Test Case Name:", tc.Name
        print "Running Test Case:", tc.Run()

    o.UnloadTestDLL()
except Exception, x:
    print "\n\nException:", x


I traced the Delphi code, everything is called fine, but I get this:

Traceback (innermost last):
  File "<stdin>", line 1, in ?
  File "d:\Apps\Python\win32com\client\dynamic.py", line 174, in __getitem__
    return self._get_good_object_(self._enum_.__getitem__(index))
  File "d:\Apps\Python\win32com\client\util.py", line 37, in __getitem__
    return self.__GetIndex(index)
  File "d:\Apps\Python\win32com\client\util.py", line 53, in __GetIndex
    result = self._oleobj_.Next(1)
SystemError: NULL result without error in call_object

There is obviously something wrong in my Delphi code (I'm learning Delphi
right now), but I really don't know what that error message means, and where
it comes from. 

Anyone could help?

Thanks,
______________________________________________________
   Gaetan Corneau
   Software Developer 
   Copernic.com 
   http://www.copernic.com
   E-mail: corg at copernic.com                         
______________________________________________________
"Les Télétubbies, c'est de la musique d'ascenseur pour les yeux"


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