void InputConnectionImpl::SetComposingText(
    const base::string16& text,
    int new_cursor_pos,
    const base::Optional<gfx::Range>& new_selection_range) {
  new_cursor_pos += text.length() - 1;

  StartStateUpdateTimer();

  const int selection_start = new_selection_range
                                  ? new_selection_range.value().start()
                                  : new_cursor_pos;
  const int selection_end =
      new_selection_range ? new_selection_range.value().end() : new_cursor_pos;

  std::string error;
  if (!ime_engine_->SetComposition(
          input_context_id_, base::UTF16ToUTF8(text).c_str(), selection_start,
          selection_end, new_cursor_pos,
          std::vector<input_method::InputMethodEngineBase::SegmentInfo>(),
          &error)) {
    LOG(ERROR) << "SetComposingText failed: pos=" << new_cursor_pos
               << ", error=\"" << error << "\"";
    return;
  }
  composing_text_ = text;
}

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.