DOCUMENT:Q167949  26-JUN-2001  [visualc]
TITLE   :FIX: OnWindowMessage Returns BOOL for HRESULT
PRODUCT :Microsoft C Compiler
PROD/VER::2.0,2.1,3.0
OPER/SYS:
KEYWORDS:kbATL200bug kbATL210bug kbATLWC kbLocalSvr kbVC500bug kbVS97sp1fix kbGrpDSMFCATL

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

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

 - The Microsoft Active Template Library (ATL), versions 2.0, 2.1, 3.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

ATL[ASCII 146]s IOleInPlaceObjectWindowless::OnWindowMessage implementation
mistakenly returns a BOOL instead of an HRESULT indicating failure when it has
actually succeeded.

CAUSE
=====

IOleInPlaceObjectWindowless::OnWindowMessage should return S_OK if processed,
otherwise S_FALSE.

ATL passes on the return from value pT->ProcessWindowMessage, which returns
TRUE if processed, otherwise FALSE.

RESOLUTION
==========

Change the following line of source code in AtlCtl.h line 1829:

      return pT->ProcessWindowMessage(pT->m_hWnd, msg, wParam,
            lParam, *plResult);

to:

      if (pT->ProcessWindowMessage(pT->m_hWnd, msg, wParam,
            lParam, *plResult))
         return S_OK;
      else
         return S_FALSE;

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug has been corrected in Visual Studio 97
Service Pack 1.

For additional information about the Visual Studio 97 Service Pack 1, please see
the following article in the Microsoft Knowledge Base:

   Q170365 INFO: Visual Studio 97 Service Packs - What, Where, and Why

(c) Microsoft Corporation 1997, All Rights Reserved. Contributions by Chuck Bell,
Microsoft Corporation


Additional query words: BOOL HRESULT OnWindowMessage

======================================================================
Keywords          : kbATL200bug kbATL210bug kbATLWC kbLocalSvr kbVC500bug kbVS97sp1fix kbGrpDSMFCATL 
Technology        : kbAudDeveloper kbATLsearch kbATL200 kbATL300 kbATL210
Version           : :2.0,2.1,3.0
Issue type        : kbbug
Solution Type     : kbfix

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

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Copyright Microsoft Corporation 2001.