Q240014: FIX: Listing Sort Function Removes Elements

Article: Q240014
Product(s): Microsoft C Compiler
Version(s): 6.0
Operating System(s): 
Keyword(s): kbLangCPP kbSTL kbVC600 kbVC600bug kbNoUpdate
Last Modified: 11-FEB-2002

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

- The Standard C++ Library, used with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, version 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

If a list has over 32K elements, list::sort removes the elements.
Please refer to the Sample Program in the MORE INFORMATION section for details.

RESOLUTION
==========

The bug is in the header file <list>.

In the sort() function:

     if (_I == _MAXN)
  	//_A[_I].merge(_X); /* remove this line and add the line below*/ 
  	_A[_I - 1].merge(_X);

In the sort(_Pr3 _Pr) function :

     if (_I == _MAXN)
  	//_A[_I].merge(_X, _Pr); /* remove this line and add the line below*/ 
  	_A[_I - 1].merge(_X, _Pr);<BR/>

If you are sorting through a list larger than 32K, increasing _MAXN from 15 to 25
would improve the performance.

NOTE: Since the resolution involves modifying a system header file, extreme care
should be taken to make sure nothing else is changed in the header file.
Microsoft is not responsible for any problems resulting due to unwanted changes
to the system header files.

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 Microsoft Visual C++ .NET.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

The following sample program demonstrates the bug.

     //test.cpp
     //Compiler options : /GX
     #include <list>
     #include <algorithm>
     #include <iostream>

     void main()
     {
       std::list<int> mylist;

       int i;
       int last = 32768;

       for (i = 0; i < last; i++)
      mylist.push_back(i);

       std::cout << "Size before sort: " << mylist.size() << "\n";
       mylist.sort();
       std::cout << "Size after sort: " << mylist.size() << "\n";
     }

     Actual Results:
     Size before sort: 32768
     Size after sort: 0

     Expected Results:
     Size before sort: 32768
     Size after sort: 32768

Additional query words: STL

======================================================================
Keywords          : kbLangCPP kbSTL kbVC600 kbVC600bug kbNoUpdate 
Technology        : kbVCsearch kbAudDeveloper kbVCLibrary
Version           : :6.0
Issue type        : kbbug
Solution Type     : kbfix

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

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.