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Q183211: FIX: Assert in AtlCtl.cpp, Line 121

Article: Q183211
Product(s): Microsoft C Compiler
Version(s): WINDOWS:2.0,2.1
Operating System(s): 
Keyword(s): kbnokeyword kbActiveX kbATL200bug kbATL210bug kbCOMt kbContainer kbCtrlCreate kbDebug k
Last Modified: 28-JUN-2001

-------------------------------------------------------------------------------
The information in this article applies to:

- The Microsoft Active Template Library (ATL), versions 2.0, 2.1, used with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 4.2b 
   - Microsoft Visual C++, 32-bit Professional Edition, version 4.2b 
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
   - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

When you insert a debug version of your ATL control into a control container
like Visual Basic, you might get an assert in AtlCtl.cpp, line The assert occurs
in the CComControlBase::IQuickActivate_QuickActivate() method that checks
whether the cbSize member of the QACONTAINER structure is equal to
sizeof(QACONTAINER):

  _ASSERTE(pQACont->cbSize >= sizeof(QACONTAINER));

CAUSE
=====

The container initializes the QACONTAINER structure and passes it into the
control using IQuickActivate::QuickActivate(). QACONTAINER is defined in Ocidl.h
that comes with both Visual C++ and the Platform SDK. However, the Platform SDK
provides a newer version of QACONTAINER that includes two additional interface
pointers. Therefore, the QACONTAINER passed in by the container doesn't match
the size of the QACONTAINER defined in the newer Ocidl.h.

RESOLUTION
==========

The assert is harmless and can be ignored. Or, you can get rid of the assert by
performing the following steps:

1. Override IQuickActivate::QuickActivate().

2. Copy the contents of CComControlBase::IQuickActivate_QuickActivate() into
  your override of IQuickActivate::QuickActivate().

3. Comment out the assert.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This problem was corrected in Visual C++ version 6.0
for Windows.

Additional query words: kbCtrl kbATL200bug kbATL210bug kbVC420 kbVC500 kbvc600fix

======================================================================
Keywords          : kbnokeyword kbActiveX kbATL200bug kbATL210bug kbCOMt kbContainer kbCtrlCreate kbDebug kbVBp kbVC420bug kbVC500bug kbVC600fix kbATL300fix kbGrpDSMFCATL 
Technology        : kbVCsearch kbAudDeveloper kbATLsearch
Version           : WINDOWS:2.0,2.1
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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