error: Pointer addition with NULL pointer. [nullPointerArithmetic]

这个错误表明正在尝试对一个NULL指针进行指针相加操作。

size_t CompoundFile::WriteData(const char *data, size_t size, int startIndex, bool isBig)    {
    if (isBig) {
        if (size == 0 && startIndex == -2)
            return startIndex;

        // Get present indices
        vector<size_t> indices;
        GetBlockIndices(startIndex, indices, true);
        size_t maxPresentBlocks = indices.size();

        // Write blocks into available space
        size_t remainingFullBlocks = size / header_.bigBlockSize_;
        size_t curIndex = 0;
        if (maxPresentBlocks != 0)            {
            for (; remainingFullBlocks && curIndex < maxPresentBlocks;
                 --remainingFullBlocks, ++curIndex)                {
                file_.Write(indices[curIndex] + 1, data + curIndex * header_.bigBlockSize_);
            }
        }
    }
}

问题出现在file_.Write这行代码，需对data进行是否为空的判断，修改如下：

size_t CompoundFile::WriteData(const char *data, size_t size, int startIndex, bool isBig)    {
    if (isBig) {
        if (size == 0 && startIndex == -2)
            return startIndex;

        // Get present indices
        vector<size_t> indices;
        GetBlockIndices(startIndex, indices, true);
        size_t maxPresentBlocks = indices.size();

        // Write blocks into available space
        size_t remainingFullBlocks = size / header_.bigBlockSize_;
        size_t curIndex = 0;
        if (maxPresentBlocks != 0)            {
            for (; remainingFullBlocks && curIndex < maxPresentBlocks;
                 --remainingFullBlocks, ++curIndex)                {
                     if (data)
                          file_.Write(indices[curIndex] + 1, data + curIndex * header_.bigBlockSize_);
            }
        }
    }
}

再次编译，报错消失。