Article ID: 172398
Article Last Modified on 11/18/2003
APPLIES TO
- The Standard C++ Library, when used with:
- Microsoft Visual C++ 5.0 Enterprise Edition
- Microsoft Visual C++ 5.0 Professional Edition
This article was previously published under Q172398
SYMPTOMS
When you assign a shorter string to an existing string that originally contained a longer string, the assignment corrupts the heap.
When running a debug build, you may see an assertion similar to the following:
CAUSE
This problem is due to a bug in the Standard C++ Library basic_string class implementation. When assigning a shorter string to an existing string that originally contained a longer string, the heap is corrupted. The assignment can be done either through operator=() or assign().
RESOLUTION
To work around the problem, call the string::erase member function before assigning the new value to the existing string.
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.
MORE INFORMATION
Steps to Reproduce Behavior
//Compile options needed: /GX
#include <crtdbg.h>
#include <string>
int main()
{
std::string str, str2;
str = "abcdefghijklmnopqrstuvwxyzabcdefghij" ;
str2 = str;
//Workaround, uncomment the following line
//str.erase() ;
str = "zyxw" ;
_CrtCheckMemory() ;
return 0;
}
Keywords: kbbug kbfix kbvc600fix KB172398
