Re: realloc() / free() BYTE* immediately after malloc() fails

From:

=?ISO-8859-1?Q?Erik_Wikstr=F6m?= <Erik-wikstrom@telia.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 06 Jun 2007 14:31:45 GMT

Message-ID:

<lzz9i.1487$ZA.986@newsb.telia.net>

On 2007-06-06 16:03, attibln wrote:

Hi,

I'm having an odd problem with a project using VisualStudio 2005 Prof.

When I execute the program below I get this message:

Debug Assertion Failed
Program: ...
File: dbgheap.c
Line: 1252
Expression: _CrtIsValidHeapPointer(pUserData)

---------- START ----------
#include "stdafx.h"

#include <iostream>
using namespace std;

int main( int argc, char * argv[] )
{
    unsigned long lU_tile_size = 2956;
    // read the tile data (jpeg file) into a buffer
    unsigned char * byP_jpeg_file = (unsigned char *)
malloc( lU_tile_size );
    if( byP_jpeg_file == NULL )
    {
        wcout << L"eek - allocating memory failed";
        return 1;
    }

    // PROBLEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEM
    realloc( byP_jpeg_file , 0 );

    return 0;
}
---------- END----------

VS2005 settings:
win32 command line executable
ATL is linked statically
Multithreaded-Debug (/MTd)
runtime checking: both
optimisation is turned off (/Od)

Please help!

Either you have some weird settings somewhere else (why do you link ATL
statically when you don't use it?) or you have not shown us all the
code. This I surmise from the fact that it compiles and runs perfectly
fine for me on the same version of VS.

--
Erik Wikstr?m