Stack around variable corrupt, not sure what the problem is

Question

Problem solved, thank you all for the help

I've got a bit of a problem here it's not something that's blowing my program up, but it's just bothering me that I can't fix it. I have a function reading in some data from a file, at the end of the execution, the stack around variable longGarbage is corrupted. I've looked around a bit and found that a possible cause is writing to invalid memory. I cleaned up some memory leaks that I had and the problem still persists. What's confusing me is that it happens when the function finishes executing, so it appears to be happening when the variable goes out of scope. Here's the code...

CHCF::CHCF(std::string fileName)
: PAKID("HVST84838672")
{
FILE * archive = fopen(fileName.c_str(), "rb");
std::string strGarbage = "";
unsigned int intGarbage = 0;
unsigned long longGarbage = 0;
unsigned char * data = 0;
char charGarbage = '0';

if (!archive)
{
    fclose (archive);
    return;
}

for (int i = 0; i < 12; i++)
{
    fread(&charGarbage, 1, 1, archive);
    strGarbage += charGarbage;
}


if (strGarbage != PAKID)
{
    fclose(archive);
    throw "Incorrect archive format";
}
strGarbage = "";

fread(&_gameID, sizeof(_gameID),1,archive);
fread(&_fileCount, sizeof(_fileCount),1,archive);

for (int i = 0; i < _fileCount; i++)
{
    fread(&longGarbage, 8,1,archive); //file offset

    fread(&intGarbage, 4, 1, archive);//fileName

    for (int i = 0; i < intGarbage; i++)
    {
        fread(&charGarbage, 1, 1, archive);
        strGarbage += charGarbage;
    }

    fread(&longGarbage, 8, 1, archive); //fileSize

    fread(&intGarbage, 4, 1, archive); //fileType

    data = new unsigned char[longGarbage];

    for (long i = 0; i < longGarbage; i++)
    {
        fread(&charGarbage, 1, 1, archive);
        data[i] = charGarbage;
    }

    switch ((FILETYPES)intGarbage)
    {
    case MAP:
        _maps.append(strGarbage, new CFileData(strGarbage, FILETYPES::MAP, data, longGarbage));
        break;

    default:
        break;
    }

    delete [] data;
    data = 0;
    strGarbage.clear();
    longGarbage = 0;

}
fclose(archive);
} //error happens here

Here is the CFileData constructor:

CFileData::CFileData(std::string fileName, FILETYPES type, unsigned char *data, long fileSize)
{
_fileName = fileName;
_type = type;
_data = new unsigned char[fileSize];

for (int i = 0; i < fileSize; i++)
    _data[i] = data[i];
}

Answer 1

1. Might I suggest std::vector instead of calling new and delete manually? Your code is not exception safe -- you leak if an exception is thrown.

2. fread(&longGarbage, 8, 1, archive); //fileSize Are you sure sizeof(long) is 8? I suspect it's 4. I believe on Linux boxes sometimes it's 8, but most everywhere else sizeof(long) is 4, and sizeof(long long) is 8.

3. What about any constructors on members of this class? They can corrupt the stack too.