bool TextIterator::handleTextNode()
{
    if (m_fullyClippedStack.top() && !m_ignoresStyleVisibility)
        return false;

    RenderText* renderer = toRenderText(m_node->renderer());
        
    m_lastTextNode = m_node;
    String str = renderer->text();

    if (!renderer->style()->collapseWhiteSpace()) {
        int runStart = m_offset;
        if (m_lastTextNodeEndedWithCollapsedSpace && hasVisibleTextNode(renderer)) {
            emitCharacter(' ', m_node, 0, runStart, runStart);
            return false;
        }
        if (!m_handledFirstLetter && renderer->isTextFragment() && !m_offset) {
            handleTextNodeFirstLetter(static_cast<RenderTextFragment*>(renderer));
            if (m_firstLetterText) {
                String firstLetter = m_firstLetterText->text();
                emitText(m_node, m_firstLetterText, m_offset, m_offset + firstLetter.length());
                m_firstLetterText = 0;
                m_textBox = 0;
                return false;
            }
        }
        if (renderer->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility)
            return false;
        int strLength = str.length();
        int end = (m_node == m_endContainer) ? m_endOffset : INT_MAX;
        int runEnd = min(strLength, end);

        if (runStart >= runEnd)
            return true;

        emitText(m_node, runStart, runEnd);
        return true;
    }

    if (renderer->firstTextBox())
        m_textBox = renderer->firstTextBox();

    bool shouldHandleFirstLetter = !m_handledFirstLetter && renderer->isTextFragment() && !m_offset;
    if (shouldHandleFirstLetter)
        handleTextNodeFirstLetter(static_cast<RenderTextFragment*>(renderer));

    if (!renderer->firstTextBox() && str.length() > 0 && !shouldHandleFirstLetter) {
        if (renderer->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility)
            return false;
        m_lastTextNodeEndedWithCollapsedSpace = true; // entire block is collapsed space
        return true;
    }

    if (m_firstLetterText)
        renderer = m_firstLetterText;

    if (renderer->containsReversedText()) {
        m_sortedTextBoxes.clear();
        for (InlineTextBox* textBox = renderer->firstTextBox(); textBox; textBox = textBox->nextTextBox()) {
            m_sortedTextBoxes.append(textBox);
        }
        std::sort(m_sortedTextBoxes.begin(), m_sortedTextBoxes.end(), InlineTextBox::compareByStart); 
        m_sortedTextBoxesPosition = 0;
        m_textBox = m_sortedTextBoxes.isEmpty() ? 0 : m_sortedTextBoxes[0];
    }

    handleTextBox();
    return true;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.