FIX: List of Fixes in VC++ 4.2 to Bugs in VC++ 4.0/VC++ 4.1 (154492)

MORE INFORMATION

Visual C++ version 4.2 fixes several Visual C++ version 4.0 and 4.1 bugs. These bugs include Developer Studio debugger problems with breakpoints and long directory structure names, and MFC database classes problems with certain ODBC drivers producing "Out of memory" errors. Many developers will find the bug fixes listed in this article to be of particular interest.

1. In an MFC application that uses the Microsoft database classes, when using certain ODBC drivers, you may get "Out of memory" errors. These errors can occur when mapping a CString to a SQL_LONGVARCHAR, SQL_VARCHAR, or other SQL data type fields if a driver returns a large precision value from SQLDescribeCol() for the column.
   
   For more information, please see the following article in the Microsoft Knowledge Base:

   148787 FIX: Run Out of Memory or Assertion in GetBufferSetLength()

2. In the Microsoft Developer Studio, you may not be stopping at breakpoints you have set if your project was built from a directory structure that contained long names. This problem did not exist in Visual C++ 4.0.
   
   For more information, please see the following article in the Microsoft Knowledge Base:

   150936 FIX: VC41 Debugger Fails to Stop on Breakpoints w/ Long Names

3. _CRTDBG_MAP_ALLOC does not work as documented. When an object is allocated through use of the new operator and dumped through use of the debugging routines in the C Run-Time Library, the allocation is reported as occurring in the Crtdbg.h file, line 512.
   
   For more information, please see the following article in the Microsoft Knowledge Base:

   140858 FIX: _CRTDBG_MAP_ALLOC Does Not Work as Documented

4. Attempting to add a function or variable to a class by using ClassView fails and returns the error message:
   
   One or more of the files for <class name> are read-only.
   
   <class name> corresponds to the class that is selected.
   
   For more information, please see the following article in the Microsoft Knowledge Base:

   140270 FIX: ClassView Add Function/Variable Fails If Header File Moved

5. When using the CCheckListBox class in MFC and specifying a style of LBS_MULTICOLUMN, the user will be unable to check or uncheck items that are not displayed in the first column.
   
   For more information, please see the following article in the Microsoft Knowledge Base:

   142960 FIX: CCheckListBox Fails with Style LBS_MULTICOLUMN

6. If the #include preprocessor directive is used in a template class definition, the compiler generates a C1001 internal compiler error in compiler file msc1.cpp, line 899.
   
   For more information, please see the following article in the Microsoft Knowledge Base:

   146000 FIX: C1001 Including Header File in Template Class Definition

7. On Windows NT, when running in debug mode using a dynamically-loaded DLL such as an OLE control with a long file name or an .exe file with a long file name, the debugger may not break at set breakpoints. You may be able to set breakpoints both before starting and while it is running, but the debugger will not break on them.
   
   For more information, please see the following article in the Microsoft Knowledge Base:

   146447 FIX: Breakpoints Not Hit for Long File Name DLL/EXE

8. It is possible to use AppWizard to create an OLE Custom Control (.ocx file) that subclasses a standard Windows control. If you choose to subclass an edit control, the control will not exhibit the same behavior as a standard edit control.
   
   For more information, please see the following article in the Microsoft Knowledge Base:

   146617 FIX: SetWindowText(NULL) Doesn't Clear .OCX Edit Control

9. Under circumstances similar to the following, ClassWizard may cause an access violation:
   
   
   1. Derive a class CRecordSet1 from CRecordSet using ClassWizard.
   2. Derive a class CRecordSet2 from CRecordSet using ClassWizard.
   3. Replace all occurrences of CRecordSet in the .cpp and .h files for CRecordSet2 with CRecordSet1. When ClassWizard is invoked to view CRecordSet2, an access violation may occur. This may also happen with CDaoRecordset class.
   For more information, please see the following article in the Microsoft Knowledge Base:

   147735 FIX: ClassWizard Quits If Class Twice Derived from CRecordSet

10. Running an application that uses the MFC DAO classes to retrieve CLongBinary data from a database may result in one or more of the following behaviors when performing a recordset move or requery:
    
    Access violations or "Out of memory" exceptions.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    147948 FIX: Errors Occurs Using DAO CLongBinary Data from Database

11. COleDateTimeSpan returns an incorrect number of days when using dates earlier than midnight December 30, 1899. Also, adding or subtracting COleDateTimeSpan objects from COleDateTime objects will produce incorrect results if the resulting date is before midnight December 30, 1899.
12. When installing ODBC drivers from the Visual C++ 4.1 CD-ROM, you may see the following error message:
    
    Setup could not open the file: "...\MSDEV\REDIST\ORACLE.HLP"
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    148916 FIX: Setup Could Not Open \Msdev\Redist\Oracle.hlp File

13. Running an application built using the MFC ODBC classes to retrieve CLongBinary date from a database may result in data truncation. If Visual C++ 4.1 is used, the truncation is only evident in release builds; debug builds work as expected.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    149137 FIX: ODBC Long Binary Functions Use SQL_NO_TOTAL Incorrectly

14. Using /O1 (minimize size) or /O2 (maximize speed) causes a C1001 internal compiler error in a try block. The error is in compiler file \school.tp2\test\c10\src\p2\main.c, line 413. Additionally, C++ exception handling must be enabled (/GX). If the warning level is set to 4 (/W4), C4702 (unreachable code) warnings are issued before C1001.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    150884 FIX: C1001 Fatal Error in File Main.c, Line 413 for /O1 or /O2

15. If the MFC CMultiLock class is used to synchronize on more than eight synchronization objects, a memory leak occurs when using CEvent, CSemaphore, or CMutex as the synchronization objects. The size of the leak equals the number of synchronization objects used multiplied by the memory needed for a BOOL variable.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    151033 FIX: Using CMultiLock Class Can Cause a Memory Leak

16. Using Visual C++ 4.0 or 4.1 C Run-time to asynchronously spawn a child process that is inheriting a pipe handle, the parent process hangs before returning from the spawn call.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    151071 FIX: Spawn Hangs When Inheriting Pipe Handle

17. When using MFC 4.0 or 4.1, an assert can occur in bardock.cpp, line 682 when CFrameWnd::LoadBarState() is called. This behavior occurs if SaveBarState() was previously called and more than one CToolBar was docked at the bottom of the window.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    151382 FIX: LoadBarState() Causes Assert In Bardock.cpp, Line 682

18. With MFC 4.0 or 4.1, the internal state of the ControlBars is corrupted when ControlBars are docked and undocked. The size of the registry key or the .INI file grows when SaveBarState is a result of this corruption.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    151446 FIX: Internal State of ControlBars Corrupted

19. When using the MFC ODBC classes with the Microsoft SQL Server ODBC driver version 2.65.0201 that ships with Microsoft SQL Server 6.5, CDBExceptions can be thrown that contain no information about what led to the exception.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    151683 FIX: MFC ODBC Exceptions Using the SQL Server 6.5 Driver

20. When installing ODBC drivers from the Visual C++ 4.1 CD-ROM by running setup from \msdev\redist, you may see the following error message:
    
    Setup could not open the file: "...\MSDEV\REDIST\QFEUPD.EXE".
    
    When this happens, you have to quit the setup program.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    152317 FIX: Setup Could Not Open \MSDEV\REDIST\QFEUPD.EXE

21. When using MFC ISAPI classes to send a POST HTTP request to an MFC ISAPI DLL, an access violation may occur in the debugger, or a message about a failed request from the Web browser may be generated.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    152365 FIX: Sending a POST HTTP Request May Cause an Access Violation

22. Using the ClassWizard to associate a short with a control on a dialog may result in an access violation when UpdateData(TRUE) is called, or in other member variables of the dialog being corrupted after the call toUpdateData(TRUE).
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    152384 FIX: DDX for Short Causes Stack Corruption

23. Generating an ISAPI filter using the MFC ISAPI Extension Wizard and selecting the option "Client Authentication Requests," will generate an ISAPI filter DLL with an OnAuthentication() member function that will never be called.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    152493 FIX: ISAPI Extension Wizard Generates Bad OnAuthentication

24. When the POST method is used to send information from an HTML form to an MFC ISAPI DLL, the last parameter in the function handling command may have extra characters that are not part of the actual input. This will happen if the last parameter is a string.
    
    For more information, please see the following article in the Microsoft Knowledge Base:

    152968 FIX: Extra Invalid Characters in String Arguments