BUG: You experience a crash in Mfc42 (d).dll during process exit on Windows 95, Windows 98, or Windows Me (271208)


The information in this article applies to:

  • Microsoft Visual C++, 32-bit Enterprise Edition 6.0, when used with:
    • Microsoft Windows Millennium Edition
    • Microsoft Windows 98
  • Microsoft Visual C++, 32-bit Professional Edition 6.0, when used with:
    • Microsoft Windows Millennium Edition
    • Microsoft Windows 98
  • Microsoft Visual C++, 32-bit Learning Edition 6.0, when used with:
    • Microsoft Windows Millennium Edition
    • Microsoft Windows 98
This article was previously published under Q271208

SYMPTOMS

When a process exits, you may experience a crash in the Mfc42.dll or Mfc42d.dll file on a computer that is running Microsoft Windows 95, Microsoft Windows 98, or Microsoft Windows Millennium (Me).

CAUSE

The Mfc42(d).dll file assumes it is cleaning up on the main thread and relies on the handle map that is stored into a thread-local storage value for the main thread. If the handle map is missing, Microsoft Foundation Class Library (MFC) may crash.

On a computer that is running Windows 95, Windows 98, or Windows Me, you can run DLL_PROCESS_DETACH on any thread, rather than the thread that called the ExitProcess function. (Microsoft Windows NT and Microsoft Windows 2000 exit the process on the thread that called ExitProcess.)

RESOLUTION

Use the static MFC library and not the shared MFC dynamic-link library (DLL).

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed in the "Applies to" section.

MORE INFORMATION

Steps to reproduce the behavior

  1. Create a new MFC project and accept all the defaults.
  2. Use class wizard to add a new handler for ID_FILE_OPEN in the CWinApp-derived class. Edit the code to read as follows:
        void CAssertApp::OnFileOpen()
    {
        CFileDialog dlg(TRUE);
        dlg.DoModal();
        ASSERT(FALSE);
    }
  3. In the message map in the Assert.cpp file, remove the line that maps ID_FILE_OPEN to the CWinApp::OnFileOpen function.
  4. Build the debug configuration.
  5. Press F5 (on the Debug menu, and then click Go).
  6. In the application, click the toolbar button to open a file.
  7. Click Cancel in the Open File dialog box.

    The assertion is hit and a dialog box titled Debug Assertion Failed! is displayed.
  8. Click Abort.
This is known to crash on Windows 98 Second Edition.
Modification Type:MajorLast Reviewed:4/29/2005
Keywords:kbtshoot kbBug KB271208 kbAudDeveloper
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